Close up of kitchen faucet with a strong stream of water Close up of kitchen faucet with a strong stream of water

The Multi-Site PFAS Health Study

About

 

 

Researcher Erin Bell, discusses study with local residents outside of Hoosick Falls clinic.
Researcher Erin Bell, discusses the study with local residents outside of the Hoosick Falls study clinic.

 

The Multi-Site PFAS Health Study (MSS) is a national health study examining the role per- and polyfluoroalkyl substances (PFAS) may play in various health outcomes. The MSS began data collection in the City of Newburg and in the Hoosick Falls area in the winter of 2021. Study visits took place at local study clinics from the Winter of 2021 through Fall of 2023. 523 adults and children in the City of Newburgh and in the Hoosick Falls area participated in the study. The success of the study would not have been possible without input and assistance from our Community Advisory Panel (CAP) and numerous community members and groups. We are looking forward to continuing these relationships as we analyze results and present findings to participants and the community. 

 

 

Researcher and Newburgh clinic staff stand at a table with flyers and other information to provide to local residents at the Newburgh Free Library.
University at Albany research staff and Newburgh study clinic staff table to provide study information to local residents at the Newburgh Free Library.

The study is funded by the Centers for Disease Control and Prevention (CDC) and the Agency for Toxic Substances and Disease Registry (ATSDR). New York’s effort is led by researchers at the University at Albany and the New York State Department of Health (NYSDOH). 

The Multi-site PFAS Health Study
George Education Center Room 254

1 University Place
Rensselaer, NY 12144
United States

Para traducir la pagina, por favor acuda a su navegador de internet. 

Tranpri itilize navigate pou ou ka tradui paj sa.

Please use your browser to translate this webpage.

Meet Our Team

 

Newburgh Summer Clinic Team 

Clinic Staff: Destini McMillan, Rashaun Providence, Riley Winters, Lovis Gordon, Serojnie Girdharry

MSS Study Support Staff: June Moore, Kelly Law, Cindy Arthur, Anonna Saha, Monica Nordstrom, Elizabeth Velasquez

(Left to Right: Rashaun Providence, Riley Winters, Destini McMillan, Erin Bell, Serojnie Girdharry, Lovis Gordon, Elizabeth Vasquez and Anonna Saha).

 

Newburgh Clinic Team

Keir Graham, Roberta Chambers, Suntiah Frierson, Jasmine Monroy, Destini McMillan, Brittany Brown and Joseph Rivera. 

Check out the Newburgh Clinic

Newburgh Clinic Team Members

(Left to Right: Keir, Roberta, Suntiah, Jasmine, Destini, and Brittany)

 

Hoosick Falls Clinic Team

Kayla Denue, Teresa Lassor, Madison Kownack, Carol Frazier and Ayaka Hisanaga

Check out the Hoosick Falls Clinic

Hoosick Falls PFAS Team standing in front of building

(Left to Right: Kayla, Teresa, and Janaye)

 

UAlbany Team

Gloria Diaz, Elisa Grimm, Jordan McAdam, Cindy Arthur, and Nicole Lee

Meet the UAlbany Team

School of Public Health Multi-Site PFAS Health Study Team

(Left to Right: Jordan, Gloria, Nicole, Elisa, and Cindy)

 

New York State Department of Health Team

Kelly Law, Elizabeth Lewis-Michl, Steven Forand, June Moore, Sana Savadatti, Gena Gallinger, and Harshal Shet

Hoosick Falls Area Multi-site PFAS Health Study Clinic Team

(Top Left to Right: Kelly, Elizabeth, Steven, and June; Bottom Left to Right: Sana, Gena, and Harshal)

 

Study Investigators

Dr. Erin Bell

Mr. Steven Forand

 

Dr. Erin Bell

Dr. Bell is a Professor of Environmental Health Sciences at the University at Albany School of Public Health. Her research interests include examining the association of environmental exposures and adverse birth and child health outcomes, including neurodevelopment. She is particularly interested in the relationship between social factors and environmental exposures and their combined impact on child development. For more information, please visit Dr. Bell's faculty page.

Mr. Steven Forand 

Mr. Steven Forand is the Section Chief, Research Scientist IV in the Bureau of Environmental and Occupational Epidemiology (NYSDOH). Mr. Forand has extensive experience working on environmental health studies and surveillance projects and community health investigations related to environmental exposures. He holds a MA in Biology from Binghamton University and a MS in Epidemiology from the University at Albany. 

Dr. Elizabeth L. Lewis-Michl (former NYSDOH Co-Principal investigator)

Dr. Lewis-Michl was the Director of the Division of the Environmental Health Assessment within the Center for Environmental Health at the New York State Department of Health (NYSDOH). Dr. Lewis-Michl has extensive experience conducting wide variety of health outcome and biomonitoring investigations including applied epidemiological research in communities with unusual environmental exposures. She holds a PhD in Socio-medical Sciences from Columbia University. 

 

 

Published Literature

Our staff is dedicated to bringing scientific information to our communities and review recently published scientific research articles. This was last updated 9/11/2023.

This page will be updated monthly. All of the articles listed have been published between 2015 and now and are peer reviewed. Older articles are available upon request. If you have any questions, please contact us by phone at 1-833-732-7697, by text at 518-898-0276, or by email at [email protected].

Esta página se actualizará mensualmente. Todos los artículos enumerados se han publicado entre 2015 y ahora. Los artículos más antiguos están disponibles bajo petición. Si tienes algunas preguntas, póngase en contacto con nosotros. Por favor contáctenos por teléfono a 1-833-732-7697, mensaje de texto a 518-898-0276, o por correo electrónico a [email protected].

Paj sa a pral mete ajou chak mwa. Tout atik ki nan lis yo te pibliye ant 2015 e kounye a. Pi gran atik yo disponib sou demann. Si ou gen nenpòt kesyon, tanpri kontakte nou. Tanpri Kontakte nou sou Telefòn a 1-833-732-7697, pa tèks a 518-898-0276, oubyen pa imèl a [email protected].


Dr. Katie Pelch and her team created a PFAS-TOX database that contains articles on PFAS and potential health outcomes that may be observed in humans, animals, or in-vitro. To maintain consistency between the PFAS-TOX database created by Dr. Pelch and our literature review webpage we have used their health outcome categories to organize our literature review webpage. If you have questions or want to discuss an article, please let us know and we will be happy to speak with you. We are able to set up a call in either Spanish or Haitian Creole. We can be reached by phone at 1-833-732-7697, by text at 518-898-0276, or by email at [email protected].

 

Infant and Childhood Health

 

Reproductive System

Reproduction includes effects on the reproductive system, reproductive function, pregnancy, and birth outcomes. Menstruation and puberty information can be found in the Hormones section. This section currently has 156 total papers: 150 since 2016. Some studies include other endocrine-disrupting chemicals (EDCs) to measure outcomes following exposure to multiple toxicants. Although a study may find, or not find, an association between PFASs and other EDCs and reproductive outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Birthweight, birth size, and birth outcomes

Associations of a Prenatal Serum Per- and Polyfluoroalkyl Substance Mixture with the Cord Serum Metabolome in the HOME Study

Study Purpose: While numerous statistical methods have been developed to quantify the potential effects of chemical mixtures, few studies have evaluated the impact of PFAS mixtures on the fetal metabolome. Understanding the impact of PFAS exposures on the fetal metabolome is important because PFAS can cross the placenta, and the fetus may be more sensitive to environmental exposures compared to later life stages. To address these research gaps, this study evaluated the impact of a mixture of PFAS [PFOS, PFOA, PFHxS, and perfluorononanoic acid (PFNA)] concentrations on the fetal metabolome.

Prenatal Exposure to PFAS, Associations with Preterm Birth and Modification by Maternal Estrogen Levels: The Maoming Birth Study

Study Purpose: Assessing modification of PFAS-preterm birth associations by the different estrogen types may shed light on the reproductive toxicity of PFAS exposure and inform public health strategies for maternal and child health. In this context, we examined associations between maternal PFAS exposure and preterm birth in 879 Chinese women and then further explored if these associations were modified by
estrogen profile.

Study Conclusion: Our findings suggest that estrogen modified the association between maternal PFAS exposure and preterm birth. Further studies on maternal PFAS exposure and preterm birth, taking interaction effects of cord estrogens into account, are warranted.

Prenatal and Early Postnatal Exposure to Persistent Organic Pollutants (POPs): What Is the Correlation between Dioxins and Long-Chain Per- and Polyfluorinated Alkyl Substances (PFAS)?

Study Purpose: The study purpose is to investigate the potential correlation between prenatal and early postnatal exposure to persistent organic pollutants (POPs), specifically dioxins and long-chain per- and polyfluorinated alkyl substances (PFAS), and their impact on male reproductive health in adulthood. The study also aims to highlight the need for cautious interpretation of epidemiological data and the consideration of other lifestyle factors that may influence male reproductive health.

Study Conclusion: The study concludes that there is a moderate correlation between dioxin I-TEq and the four PFAS in maternal blood drawn 11 months after delivery. The study suggests that the observed correlations of plasma levels of dioxins and PFAS make simple association analyses of biological parameters and single compound groups difficult with respect to generating hypotheses of causal relationships, if not all compound groups can be analyzed in parallel. The study also highlights the need for cautious interpretation of epidemiological data with respect to causality, given the complex issue of co-exposure of different possible agents in a mixture with different doses, different possible windows of exposure, and the long latency time between exposure and possible effects.

Environmental exposure to per- and perfluoroalkyl substances in early pregnancy and newborn anogenital distance: A prospective cohort study

Study Purpose: The primary aim of this study was to investigate the potential associations between maternal exposure to PFAS during pregnancy and AGD in newborns.

Study Conclusion: This prospective cohort study has yielded additional evidence supporting the notion that PFAS exposure has the potential to influence AGD in both boys and girls. 

Prenatal exposure to per- and polyfluoroalkyl substances and DNA methylation in the placenta: A prospective cohort study

Study Purpose: Epidemiological studies regarding the relationship between per- and polyfluoroalkyl substances (PFAS) and DNA methylation were limited. We investigated the associations of maternal PFAS concentrations with placental DNA
methylation and examined the mediating role of methylation changes between PFAS and infant development.

Study Conclusion: Prenatal exposure to PFAS may contribute to alterations in the DNA methylation profile of the placental genome, most notably in angiogenesis and neurological development. Among the five candidate genes(i.e., CHST7, FGF13, IRS4, PHOX2A, and PLXDC1), placental DNA methylation of CHST7, IRS4, and PLXDC1 was associated with PFAS exposure. Additionally, decreased methylation of PLXDC1 may mediatethe association between PFOA exposure and increased risk of developmental delay in infants.

Prenatal per- and polyfluoroalkyl substances (PFAS) exposure in relation to preterm birth subtypes and size-for-gestational age in the LIFECODES cohort 2006-2008

Study Purpose: Many studies have linked prenatal PFAS exposure with increased risk of preterm birth and small for gestational age. This study examines associations of PFAS with subtypes of preterm birth, birthweight, and size for gestational age.

Study Conclusion: The effects of prenatal exposure to single and multiple types of PFAS on preterm birth and large for gestational age depend on the sex of the offspring. 

Fetal Glucocorticoid Mediates the Association between Prenatal Per- and Polyfluoroalkyl Substance Exposure and Neonatal Growth Index: Evidence from a Birth Cohort Study

Study Purpose: Glucocorticoid plays a role in the growth and organ development of the fetus. However, the effect of glucocorticoid on the association between PFAS exposure and fetal growth is unknown. This study measurements cortisol (active glucocorticoid in humans) and PFAS in maternal serum. The effects of newborn cortisol levels on the relationship between maternal PFAS and the neonatal growth index were estimated. 

Study Conclusion: These findings suggest that fetal glucocorticoid can affect the relationship between prenatal PFAS exposure and neonatal growth index. Higher maternal PFAS was also associated with greater fetal cortisol.

Associations between maternal exposure to perfluoroalkylated substances (PFASs) and infant birth weight: a meta-analysis

Study Purpose: The objective of this study was to evaluate associations between maternal exposure to PFAS and infant birth weight.

Study Conclusion: These findings suggest an adverse relationship between maternal exposure to PFAS during pregnancy and infant birth weight, and this relationship appears to vary by the type of PFAS and the geographical region. 

Association between prenatal exposure to perfluoroalkyl substance mixtures and intrauterine growth restriction risk: A large, nested case-control study in Guangxi, China

Study Purpose: Intrauterine growth restriction (IUGR) is an abnormal fetal growth pattern that can affect neonatal development. IUGR may be affected by prenatal exposure to environmental pollutants, but research linking PFAS exposure to IUGR is limited, with inconsistent results. This study aims to investigate the association between PFAS exposure and IUGR.

Study Conclusion: This study observed a relationship between increasing maternal exposure to PFHpA, PFDoA, and PFHxS with the risk of IUGR. Further study is needed to better understand the mechanisms behind this relationship.

Newborn metabolomic signatures of maternal per- and polyfluoroalkyl substance exposure and reduced length of gestation

Study Purpose: This study assessed the relationship between prenatal PFAS exposure and gestational age at birth and other birth outcomes among African Americans in Atlanta, GA.

Study Conclusion: Increases in maternal PFAS levels were associated with early term birth and medically indicated early birth prior to full-term. Newborn blood samples revealed disruptions in biological pathways that may be related to the PFAS and gestational at birth findings. 

Association between perfluoroalkyl and polyfluoroalkyl substances exposure and fetal overgrowth: A prospective birth cohort study conducted in China

Study Purpose: Prenatal exposure to PFAS has been associated with gestational diabetes and increased body fatness, but data on fetal overgrowth outcomes, including macrosomia and large for gestational age (LGA) is lacking. This study explores the relationship between maternal PFAS exposure and macrosomia and large for gestational age.

Study Conclusion: This study suggests that associations between PFAS and fetal overgrowth depend on the level of exposure. When the level of PFDA exceeded a threshold, it was associated with greater risks of developing macrosomia and LGA. When PFOA levels reached a threshold, it was associated with a higher risk of macrosomia. 

Prenatal exposure to per- and polyfluoroalkyl substances and pregnancy outcome in Austria

Study Purpose: PFAS may harm reproductive health. This study investigates possible associations between prenatal PFAS exposure and adverse pregnancy outcomes. 

Study Conclusion: This study found that exposure to PFOA, PFOS, PFHxS, and PFNA has decreased from 2010/2012 to 2017/2019. Further studies are needed to assess the relationship between prenatal PFAS exposure and pregnancy outcomes, in particular to confirm findings in this study of elevated PFDA levels contributing to increased risk of small for gestational age.

Association of Early Pregnancy Perfluoroalkyl and Polyfluoroalkyl Substance Exposure With Birth Outcomes

Study Purpose: PFAS have been linked to adverse birth outcomes. Previous research has shown that higher folate levels are associated with lower blood PFAS concentrations. This study examines whether prenatal folate levels modify the relationship between pregnancy PFAS concentrations, birth weight, and gestational age.

Study Conclusion: In this study, higher early pregnancy PFAS concentrations were associated with lower birth weight and gestational age, and higher risk of low birth weight only among mothers whose early pregnancy dietary folate intake or plasma folate levels were low (below the 25th percentiles). Findings suggest that mothers with the lowest folate status were more susceptible to PFAS-related adverse birth outcomes. These findings should be confirmed in future studies.

Metals and per- and polyfluoroalkyl substances mixtures and birth outcomes in the New Hampshire Birth Cohort Study: Beyond single-class mixture approaches

Study Purpose: This study aims to investigate the joint and individual impacts of PFAS, toxic metals, and essential elements on birth outcomes in a group of mothers and children.

Study Conclusion: This study identified a positive relationship between prenatal manganese (Mn) and head circumference at birth among male infants. Our findings suggest that, within the range of concentrations represented in our population, higher maternal Mn in pregnancy may contribute to a larger infant head circumference at birth. These findings need to be further investigated.

Pregnancy-related hemodynamic biomarkers in relation to trimester-specific maternal per - and polyfluoroalkyl substances exposures and adverse birth outcomes

Study Purpose: The distribution of PFAS in maternal and fetal tissues might be affected by pregnancy-related cardiovascular changes that occur. During pregnancy, blood volume increases and kidney function changes. These changes are thought to affect associations between PFAS exposure measures in late pregnancy with gestational length and fetal growth. This study analyzes two pregnancy-related cardiovascular markers, creatinine and estimated glomerular filtration rate (a marker of kidney function), as factors affecting trimester-specific relationships between maternal PFAS concentrations and adverse birth outcomes.

Study Conclusion: The results presented here demonstrate that the associations between prenatal PFAS exposure and adverse birth outcomes are modestly influenced by trimester of pregnancy, but are not strongly influenced by pregnancy-related cardiovascular changes. 

Unveiling Distribution of Per- and Polyfluoroalkyl Substances in Matched Placenta-Serum Tetrads: Novel Implications for Birth Outcome Mediated by Placental Vascular Disruption

Study Purpose: The placenta is needed for fetal development and can be a source of exposure to PFAS chemicals for the fetus. In this study, fetal-side placenta, maternal-side placenta, cord blood, and maternal blood samples were collected and PFAS levels measured to understand the distribution of PFAS in the placenta. 

Study Conclusion: This study explored comprehensive PFAS distribution profiles in placental-serum tetrads and revealed adverse placental vascular effects of PFASs.

Mediation effects of DNA methylation and hydroxymethylation on birth outcomes after prenatal per- and polyfluoroalkyl substances (PFAS) exposure in the Michigan mother-infant Pairs cohort

Study Purpose: PFAS may impact development of the genome, but current human evidence is limited to assessments of total DNA methylation, or DNA changes. This study assessed the associations between first trimester PFAS exposures with newborn DNA methylation. Then, the study evaluates associations between PFAS exposure and birth outcomes and whether DNA methylation impacts this association. 

Study Conclusion: This study demonstrates the role of specific types of DNA methylation on the relationship between PFAS exposure and birth outcomes. These results suggest that 5-mC and 5-hmC DNA methylation may be more sensitive to the developmental impacts of PFAS than total DNA methylation.

Mediating effect of endocrine hormones on association between per- and polyfluoroalkyl substances exposure and birth size: Findings from sheyang mini birth cohort study

Study Purpose: Prenatal exposure to PFAS has been reported to affect fetal growth, but current results have been inconsistent and the mechanism remains unclear. This study aims to evaluate the associations of prenatal exposure to single and/or multiple PFAS with birth size and to investigate whether thyroid hormones and reproductive hormones impact these associations.

Study Conclusion: Prenatal PFAS mixture exposure, especially PFNA, was associated with larger birth size. Neonatal thyroid stimulating hormone (TSH) levels partially affected this relationship.

Prenatal exposure to persistent and non-persistent chemical mixtures and associations with adverse birth outcomes in the Atlanta African American Maternal-Child Cohort

Study Purpose: African Americans experience higher rates of preterm birth and fetal growth restriction relative to other pregnant populations. Different exposure prenatally to environmental chemicals may partially explain these health disparities, as African Americans are disproportionately exposed to environmental hazards. This study examines the individual and mixture effects of PFAS and other environmental chemicals on gestational age at birth and birthweight for gestational age within a study of pregnant African Americans.

Study Conclusion: These findings suggest that prenatal exposure to multiple classes of environmental chemicals is associated with reduced gestational age and birthweight in African Americans.

Serum Concentrations of Selected Poly- and Perfluoroalkyl Substances (PFASs) in Pregnant Women and Associations with Birth Outcomes. A Cross-Sectional Study from Southern Malawi

Study Purpose: Exposure to PFAS has been associated with adverse pregnancy outcomes. The aim of this study was to examine factors associated with different serum PFAS concentrations in late pregnancy and their relationship with birth outcomes in Malawi.

Study Conclusion: Area of residence was the predictor for high concentrations of PFASs detected in serum of women from urban settings. Maternal serum PFAS concentrations were associated with some but not all birth outcomes. PFAS concentrations assessed in the present study, except PFHxS, are lower as compared to other parts of the world. Follow-up studies are needed to evaluate the association between the source of drinking water and maternal serum PFAS concentrations. 

Prenatal exposure to persistent organic pollutants and changes in infant growth and childhood growth trajectories

Study Purpose: This study investigates associations between prenatal exposure to persistent organic pollutants, including PFAS, and growth during infancy and childhood.

Study Conclusion: This study provides some support for the effect of prenatal PCB-153 on elevated infant growth. Prenatal p,p’-DDE may be associated with reduced infant growth. No persistent effects of prenatal POP exposures across childhood were observed. Larger prospective studies with repeated measures and advanced multi-pollutant approaches are warranted to validate these results and inform policy recommendations.

Systematic review and meta-analysis of birthweight and PFNA exposures

Study Purpose: This paper reviews published literature on the association between PFNA exposure and birthweight and assessed the potential risk of bias and sensitivity in the included studies. As part of this effort, the study assesses statistical similarities between the studies, evaluates the potential for publication bias, and uses meta-analyses to highlight any differences. 

Study Conclusion: Overall, we detected a sizeable deficit in mean birthweight per each unit increase of PFNA that was seen across numerous analyses and showed little evidence of either publication bias or between-study heterogeneity. Importantly, this is the first PFAS meta-analysis to report birthweight deficits that do not appear to be fully explained by sample timing considerations and pregnancy hemodynamics. 

Reduced Birth Weight and Exposure to Per- and Polyfluoroalkyl Substances: A Review of Possible Underlying Mechanisms Using the AOP-HelpFinder

Study Purpose: Prenatal exposure to PFAS may impair fetal growth. This study used the Adverse Outcome Pathway (AOP)-helpFinder tool to search PubMed for studies published until March 2021 that examined PFAS exposure in relation to birth weight, oxidative stress, hormones/hormone receptors, or growth signaling pathways. 

Study Conclusion: Overall, data suggest thyroid-damaging effects of PFAS affecting thyroid hormones, thyroid hormone gene expression, and histology that are associated in animal studies with decreased body and organ weight. The effects of PFAS on the complex relationships between oxidative stress, endocrine system function, adipogenesis, and fetal growth should be further explored.

Detected prenatal perfluorooctanoic acid (PFOA) exposure is associated with decreased fetal head biometric parameters in participants experiencing higher perceived stress during pregnancy in the MADRES cohort

Study Purpose: PFAS are known to cross the placenta during pregnancy. This study examines the influence of maternal PFAS levels on in utero fetal growth trajectories and assessed whether maternal stress modified these associations.

Study Conclusion: Maternal serum PFOA concentrations were associated with lower fetal head circumference and biparietal diameter growth trajectories across pregnancy and these associations were stronger among participants reporting higher levels of perceived stress.

High maternal glucose exacerbates the association between prenatal per- and polyfluoroalkyl substance exposure and reduced birth weight

Study Purpose: PFAS exposure has been associated with reduced birth weight. However, the association may be complicated by glucose status due to PFAS impact on fetal growth and placental transport. The objective of this study was to examine whether maternal glucose status modifies the association between prenatal PFAS exposure and birth weight z-score.

Study Conclusion: High maternal glucose level may increase the risk of reduced birth weight z-score related to prenatal PFAS exposure. Moreover, exploring these estimated effects with different FPG cutoffs may contribute to providing intervention strategies for pregnant women with high PFAS exposure.

Perfluoroalkyl Mixture Exposure in Relation to Fetal Growth: Potential Roles of Maternal Characteristics and Associations with Birth Outcomes

Study Purpose: PFAS exposure is suggested to interfere with fetal growth. However, limited investigations considered the roles of parity and delivery on PFAS distributions and the joint effects of PFAS mixtures on birth outcomes.

Study Conclusion: Maternal age, BMI, parity, and delivery mode were considered as influencing factors of PFAS burden. Multivariate linear regression suggested that prenatal exposure to PFOA, PFOS, and PFNS significantly reduced neonatal birth weight. PFHpA and PFHpS exposure were associated with increased respiration scores. PFOA and PFNS were identified as risk factors to preterm birth. 

Gestational exposure to perfluoroalkyl substances is associated with placental DNA methylation and birth size

Study Purpose: DNA methylation is one potential mechanism for the effects of gestational exposure to PFAS on fetal growth. This study investigated pregnant women who participated in a study in Northern China and determined the concentrations of PFAS and the methylation of two genes related to fetal growth and one marker for methylation in placental tissue.

Study Conclusion: This study measured 11 PFASs and DNA methylation of two typical genes related to fetal growth (IGF2 and NR3C1) and one surrogate marker for global genome (LINE-1) in the placenta of Chinese pregnant women. The data indicated that intrauterine PFASs exposure affected placental DNA methylation and reduced fetal growth and these effects showed some sex-specific differences. In view of relatively small sample size, more studies are needed to interrogate these findings.

Per- and polyfluoroalkyl substances and psychosocial stressors have a joint effect on adverse pregnancy outcomes in the Atlanta African American Maternal-Child cohort

Study Purpose: African Americans experience high rates of adverse pregnancy outcomes relative to white Americans. Differences in in utero exposure to environmental chemicals and psychosocial stressors may explain some of these disparities, as exposures to PFAS and experiences of discrimination have been linked to adverse birth outcomes. This study examines the joint effects of PFAS and psychosocial stress on birth outcomes in African Americans.

Study Conclusion: This study found that a simultaneous increase in in utero PFAS exposure and psychosocial stressors was associated with reduced birthweight for gestational age.

Preconception exposure to perfluoroalkyl and polyfluoroalkyl substances and couple fecundity: A couple-based exploration

Study Purpose: This study aimed to assess the effects of PFAS on time to pregnancy and infertility, with a focus on the effects of PFAS exposure from either partner.

Study Conclusion: In this study population, exposure to 6:2 diPAP and PFHpA (two emerging PFAS replacement) in women was associated with reduced couple fecundity, which was shown as prolonged time to pregnancy and increased risk of infertility. Certain PFAS protected couple fecundity in men, suggesting that PFAS may exert different effects in men and women related to couple fecundity.

Association between prenatal exposure to perfluoroalkyl substances and anogenital distance in female neonates

Study Purpose: Anogenital distance (AGD) is a marker of intrauterine androgen exposure and an indicator of genital development. An animal study reported that female rats exposed to PFOA or PFOS during 1-5 days following birth exhibited longer AGD, while studies in humans have been inconsistent. This study aimed to examine the effects of prenatal exposure to PFAS on the AGD in female neonates.

Study Conclusion: High maternal concentrations of PFAS were associated with increased AGD in female neonates, indicating that PFAS may impair reproductive development in female offspring in early life.

Associations of prenatal exposure to perfluoroalkyl substances with preterm birth: A family-based birth cohort study

Study Purpose: Studies have investigated associations between maternal exposure to PFAS and preterm birth, but the impact of paternal and overall family exposure to PFAS mixtures on preterm birth remains unknown. To address this knowledge gap, a total of 355 preterm births and 481 controls were selected for a family-based birth cohort study in a coastal area of China, between 2016 and 2018. 

Study Conclusion: These results suggest that higher family-level PFNA and PFDA exposure was associated with greater preterm birth risk, although the results for individual paternal, maternal and neonatal PFAS exposures were contradictory. These findings highlight a need to study further family PFAS concentrations and seafood consumption when assessing reproductive toxicity.

Gestational per- and polyfluoroalkyl substances exposure and infant body mass index trajectory in the New Hampshire Birth Cohort Study

Study Purpose: Mothers participating in the New Hampshire Birth Cohort Study (NHBCS) provided a plasma sample during pregnancy to measure concentrations of seven PFAS, and infant weight and length were measured in infants between birth and 12 months.

Study Conclusion: This study observed sex-specific associations of prenatal PFAS during pregnancy with growth patterns during infancy. Greater BMI growth during the first year was observed among girls to mothers with higher pregnancy concentrations of PFOS.

Effect of perfluoroalkyl exposure in pregnancy and infancy on intrauterine and childhood growth and anthropometry. Sub study from COPSAC2010 birth cohort

Study Purpose: PFOS and PFOA have a range of suspected negative health effects. It is hypothesized that exposure during prenatal and early postnatal life may have effects on intrauterine and childhood growth. This study investigates effects of PFOS and PFOS in pregnancy and infancy on intrauterine and childhood growth and anthropometry.

Study Conclusion: Higher PFOS and PFOA plasma concentrations during pregnancy had detrimental effects on fetal growth. The effects on childhood growth were not similar as PFOA increased child height, opposite of PFOS in models. Sex specific growth effects were affected by an altered lactosyl-ceramide metabolism, which may be a possible effect of PFOS exposure.

Association of single and multiple perfluoroalkyl substances exposure with preterm birth: Results from a Chinese birth cohort study

Study Purpose: PFAS are persistent organic pollutants that may lead to adverse birth outcomes, such as preterm birth (PTB). However, previous studies have reported inconsistent results on the association between PFASs and PTB, and lack of the epidemiological evidence regarding the effect of PFASs mixture on PTB. This study aimed to explore association of individual and multiple exposure to PFASs with PTB.

Study Conclusion: Overall, this study provided evidence of the effect of PFAS on preterm birth and found that prenatal exposure to PFAS mixtures was associated with higher risk of preterm birth, in which PFHpA, PFOS, and PFBS were the main contributors. 

Prenatal PFAS and psychosocial stress exposures in relation to fetal growth in two pregnancy cohorts: Applying environmental mixture methods to chemical and non-chemical stressors

Study Purpose: Prenatal exposure to individual PFAS and psychosocial stressors have been associated with reductions in fetal growth. Studies suggest cumulative or joint effects of chemical and non-chemical stressors on fetal growth. However, few studies have examined PFAS and non-chemical stressors together as a mixture, which better reflects real life exposure patterns. We examined joint associations between PFAS, perceived stress, and depression, and fetal growth using two approaches developed for exposure mixtures.

Study Conclusion: The study found that PFAS, perceived stress, and depression in combination were modestly associated with less fetal growth, which supports prior studies indicating that chemical and non-chemical stressors are jointly associated with adverse health outcomes.

Association Between Exposure to Per- and Polyfluoroalkyl Substances and Birth Outcomes: A Systematic Review and Meta-Analysis

Study Purpose: Emerging evidence suggests that PFAS affect birth outcomes, but the evidence is inconsistent. Therefore, this study aimed to systematically review the epidemiological evidence on PFAS exposure and birth outcomes.

Study Conclusion: This study showed that PFAS exposure was significantly associated with increased risks of various adverse birth outcomes and that different birth outcome indicators had different degrees of sensitivity to PFAS.  More studies are needed to confirm these results.

Associations between prenatal exposure to perfluoroalkyl substances, hypomethylation of MEST imprinted gene and birth outcomes

Study Purpose: PFAS exposure has been linked to adverse birth outcomes, but the underlying mechanism is not understood. DNA methylation changes in the MEST gene may be a mechanism of the prenatal exposure effects of PFASs on fetal growth. The aim of the study was to investigate the prenatal PFAS exposure effects on DNA methylation changes in MEST genes involved in fetal growth.

Study Conclusion: In conclusion, our results suggest that prenatal PFAS exposure, especially PFOS, is associated with lower methylation levels at MEST promoter region, which not only leverages the role of imprinted gene in ensuring the integrity of fetal growth but also provides a potential mechanism for evaluating the prenatal exposure effect.

High in Utero Exposure to Perfluoroalkyl Substances from Drinking Water and Birth Weight: A Cohort Study among Infants in Ronneby, Sweden

Study Purpose: In utero PFAS exposure can influence birth weight, but little is known about the effects at very high levels. This study aimed to examine the association between in utero PFAS exposure and birth weight. 

Study Conclusion: This study shows that high exposure to PFAS may influence birth weight in a sex-specific way, though this is likely a minor influence.

Concentrations of per- and polyfluoroalkyl substances (PFAS) in human placental tissues and associations with birth outcomes

Study Purpose: Previous studies have observed associations between maternal serum PFAS concentrations and adverse pregnancy and birth outcomes such as lower birth weight or pre-eclampsia; however, few studies have explored these associations with birth outcomes and placental tissue PFAS concentrations. The goal of this study was to measure placental PFAS concentrations and examine associations with birth outcomes. 

Study Conclusion: The present study shows that several PFAS are frequently detected in the placenta, and our observed associations with birth outcomes indicate potential concern for adverse health effects on infants exposed to the highest levels of PFAS exposure. In this study, PFAS placental exposure was associated with sex-specific birth outcomes. They found that the highest exposure of placental PFOS was associated with lower birth weight for gestational age in infant males and higher birth weight in female infants.

Relationships between maternal perfluoroalkyl substance levels, polymorphisms of receptor genes, and adverse birth outcomes in the Hokkaido birth cohort study, Japan

Study Purpose: The goal of this study was to look at the association between PFOA and PFOS in third trimester women's blood samples, maternal genotypes, and birth outcomes in their children.

Study Conclusion: PFOS levels during pregnancy were associated with decreased birth weight, chest circumference, and birth Ponderal index (a measure of thinness at birth) and that those associations were different according to the maternal genotype LXRB. Further studies may help identify more vulnerable or preventive genetic groups.

Per- and polyfluoroalkyl substance (PFAS) exposure, maternal metabolomic perturbation, and fetal growth in African American women: A meet-in-the-middle approach

Study Purpose: Prenatal exposures to PFAS have been linked to reduced fetal growth. This study aims to investigate biological pathways and biomarkers underlying the association between serum PFAS and fetal growth using high-resolution metabolomics in a cohort of pregnant African American women in the Atlanta area, Georgia.

Study Conclusion: In this cohort of pregnant African American women, higher serum concentrations of PFOA and PFNA were associated with reduced fetal growth. Perturbations of biological pathways involved in amino acid, lipid and fatty acid, bile acid, and androgenic hormone metabolism were associated with PFAS exposures and reduced fetal growth, and uric acid was shown to be a potential intermediate biomarker. Our results provide opportunities for future studies to develop early detection and intervention for PFAS-induced fetal growth restriction.

Associations between exposure to perfluoroalkyl substances and birth outcomes: A meta-analysis

Study Purpose: This study reviews the published literature on the effects of prenatal PFAS exposure on birth outcomes, specifically premature birth, low birth weight, small for gestational age, and miscarriage.

Study Conclusion: In this study, we observed significant associations between PFOS and premature birth, PFOA and miscarriage, and PFOS and low birth weight. Study region, sampling time, and sample were potential sources of differences between the studies included in this paper. 

Association of maternal exposure to perfluoroalkyl and polyfluoroalkyl substances with infant growth from birth to 12 months: A prospective cohort study

Study Purpose: Although maternal PFASs have been associated with adverse birth outcomes, much less is known about their impact on infant growth during early infancy. This study investigates the association between maternal PFASs exposure and infant growth during the first 12 months of life.

Study Conclusion: In this study, there were negative associations found for maternal PFHpA exposure and infant length and PFBS exposure and weight and BMI. Maternal PFDoA exposure was positively associated with weight and BMI. The adverse association of maternal PFHpA exposure and infant length was more pronounced in males.

Early pregnancy loss: Do Per- and polyfluoroalkyl substances matter?

Study Purpose: PFAS can transfer across the blood-follicle barrier. However, it is unknown whether PFAS can affect human fertility. This study aims to analyze the associations of women's exposure to PFAs with pregnancy loss, the relevant processes of fertilization, zygote implantation, and embryo development.

Study Conclusion: Overall, this study concluded that most PFAS were not associated with early pregnancy loss at the current average exposure levels. As for the PFDA, there may exist susceptibility among different populations.

Association between maternal exposure to perfluoroalkyl and polyfluoroalkyl substances and risks of adverse pregnancy outcomes: A systematic review and meta-analysis

Study Purpose: This reviews and analyzes previous studies on the relationship of maternal PFAS exposure and adverse pregnancy outcomes.

Study Conclusion: It was found that maternal exposure to PFOS could be positively associated with preterm birth, while no statistically significant association have been found between PFASs exposure and miscarriage and stillbirth. Epidemiological evidence to date are insufficient to draw definitive conclusions on potential toxicities of PFASs with stronger statistical power.

Prenatal exposure to mixtures of persistent endocrine disrupting chemicals and postnatal body size in British girls

Study Purpose: This study investigates the association of prenatal exposure to endocrine disrupting chemicals such as PFAS, PCBs, and OCPS as mixtures with postnatal body size in female offspring.

Study Conclusion: This study found an inverse association between prenatal exposure to PFAS, PCBs, and OCPs and longitudinal postnatal body size through age 19 months.

Associations of paternal and maternal per- and polyfluoroalkyl substances exposure with cord serum reproductive hormones, placental steroidogenic enzyme and birth weight

Study Purpose: Maternal PFAS exposure has been associated with placental function and fetal growth. In this study, they evaluate the associations of maternal or paternal PFAS levels with placental function and fetal growth measures.

Study Conclusion: Several maternal PFAS were associated with fetal steroid hormones and placental enzymes. Despite a correlation of PFAS level within the couples, no association was found for paternal PFAS exposure on these outcomes. The findings suggest the intrauterine PFAS exposure effect on fetal endocrine hormones and growth is unlikely to be confounded by exposure sources or familial factors shared within the couples.

The relationship between maternal perfluoroalkylated substances exposure and low birth weight of offspring: a systematic review and meta-analysis

Study Purpose: This article reviews past studies to assess the association between maternal PFAS exposure and low birth weight in offspring.

Study Conclusion: The present meta-analysis showed a significant positive association between maternal prenatal PFOS exposure and LBW of offspring, but no association between maternal PFOA exposure and LBW of offspring. Meanwhile, we observed regional factors might influence the occurrence of LBW

Per- and polyfluoroalkyl substances exposure during pregnancy and adverse pregnancy and birth outcomes: A systematic review and meta-analysis

Study Purpose: Exposure to PFAS during pregnancy has been suggested to be associated with adverse pregnancy and birth outcomes; however, the findings have been inconsistent. This study provides an overview of these associations.

Study Conclusion: Our findings indicated that PFOS, PFOA and PFNA exposure during pregnancy might be associated with increased preterm birth risk and that PFAS exposure might be associated with the risk of miscarriage and preeclampsia. Due to the limited evidence obtained for most associations, additional studies are required to confirm these findings.

Effects of gestational exposures to chemical mixtures on birth weight using Bayesian factor analysis in the Health Outcome and Measures of Environment (HOME) Study

Study Purpose: This study looks at the effects of gestational exposures to chemical mixtures (including PFAS) on infant birth weight.

Study Conclusion: This study used three different statistical approaches to examine the association between birth weight and prenatal exposures to seven types of environmental chemical mixtures. They found that PCBs and PFASs displayed strong associations with reduced birth weight.

Exploring associations between prenatal exposure to multiple endocrine disruptors and birth weight with exposure continuum mapping

Study Purpose: This study examines how prenatal exposure to environmental mixtures influence birth weight or other adverse outcomes

Study Conclusion: Findings from our study revealed a wide range of prenatal exposure scenarios and found that combinations exhibiting higher levels of PBDEs were associated with lower birth weight and combinations with higher levels of PCBs and PFAS were associated with increased birth weight. Our ECM approach provides a promising framework for supporting studies of other exposure mixtures.

Prenatal exposure to mixtures of persistent endocrine-disrupting chemicals and birth size in a population-based cohort of British girls

Study Purpose: This study investigates the association of prenatal exposure to mixtures of PFASs, PCBs, and pesticides with birth size among female offspring in the United Kingdom.

Study Conclusion: These results are consistent with the hypothesis that prenatal exposure to mixtures of endocrine-disrupting chemicals may affect birth size.

PFAS concentration during pregnancy in relation to cardiometabolic health and birth outcomes

Study Purpose: To examine the relationship between PFAS concentration during pregnancy in relation to cardiometabolic health and birth outcomes.

Study Conclusion: This study observed a positive association between PFAS exposure and serum-lipid concentrations. No association was observed between PFAS exposure and birth weight. PFNA was associated with preterm birth.

Associations between prenatal maternal exposure to per- and polyfluoroalkyl substances (PFAS) and polybrominated diphenyl ethers (PBDEs) and birth outcomes among pregnant women in San Francisco

Study Purpose: To observe the associations between prenatal maternal exposure PFAS and PBDEs, and birth outcomes among pregnant women in San Francisco.

Study Conclusion: Most PFAS were not associated with adverse birth outcomes.

Persistent organic pollutants exposure in newborn dried blood spots and infant weight status: A case-control study of low-income Hispanic mother-infant pairs

Study Purpose: This study looks at the associations between PFAS and other pollutant exposure and birth weight and overweight status at 18 months old.

Study Conclusion: Some PFASs were associated with lower birth weight. No associations with infant overweight status at 18 months were observed.

Per- and polyfluoroalkyl substances in drinking water and birthweight in the US: A county-level study

Study Purpose: This study used public data to examine potential associations between PFAS in drinking water and birthweight at county levels.

Study Conclusion: Associations between PFAS and birthweight varied by the PFAS chemical in this study. Conclusions should be interpretation due to limitations of the 2 public datasets used.

Exposure to per- and polyfluorinated alkyl substances in pregnant Brazilian women and its association with fetal growth

Study Purpose: In this study, concentrations of PFAS were determined in the second trimester of pregnancy in Brazilian women.

Study Conclusion: To the best of our knowledge, this is the first study to assess whole blood concentrations of PFASs in pregnant Brazilian women. The results suggest ubiquitous exposure to PFOS and PFOA in pregnant women from Ribeirao Preto, an industrialized region in Brazil. PFOS and PFOA concentrations in pregnant women were positively associated with IUGR (p < 0.05). Further studies are needed to evaluate long-term effects of prenatal exposure of PFASs on developmental outcomes in children.

Associations of Exposure to Perfluoroalkyl Substances With Thyroid Hormone Concentrations and Birth Size

Study Purpose: To determine the associations between maternal serum-PFAS concentrations and birth weight, birth length, and head circumference.

Study Conclusion: In this study, several PFASs were negatively associated with birth size and increased thyroid hormone levels; however, this did not explain lower birth weight among children exposed to PFAS.

Exposure to PFAS and small for gestational age newborns: A birth records study in Veneto Region (Italy)

Study Purpose: To examine the association between PFAS exposure and the risk of small for gestational age in a PFAS contaminated area.

Study Conclusion: The findings suggest that living in a contaminated area by PFAS may have an effect on fetal growth. Individual data on exposure is needed to confirm the direct association.   

Prenatal exposure to 11 perfluoroalkyl substances and fetal growth: A large-scale, prospective birth cohort study

Study Purpose: To investigate whether prenatal maternal exposure to 11 PFAS is associated with fetal growth.

Study Conclusion: The study results suggest that prenatal, maternal exposure to PFAS with longer carbon chains may have effect on fetal growth.

Maternal serum levels of perfluoroalkyl substances in early pregnancy and offspring birth weight

Study Purpose: To examine associations between first-trimester exposure to PFAS and birth weight and examine differences between boys and girls.

Study Conclusion: This study observed associations between prenatal exposure for five different PFASs and birth weight, with more pronounced associations in girls than in boys.

Prenatal exposure to per- and polyfluoroalkyl substances and infant growth and adiposity: the Healthy Start Study

Study Purpose: To test the hypothesis that faster growth in early infancy may be associated with maternal PFAS concentrations.

Study Conclusion: Although maternal PFAS concentrations are inversely associated with infant weight and adiposity at birth, rapid gain may occur in infancy, particularly in fat mass.      

First-trimester maternal concentrations of polyfluoroalkyl substances and fetal growth throughout pregnancy

Study Purpose: To determine the association between first-trimester maternal concentrations of PFAS and fetal growth.

Study Conclusion: Study results did not suggest an overall association between prenatal PFASs and fetal growth.

Maternal serum concentrations of perfluoroalkyl substances and birth size in British boys

Study Purpose: To determine the association of prenatal maternal serum concentrations and birth size in boys.

Study Conclusion: Prenatal exposure to high levels of PFOS may be associated with reduced birth size in male infants.

Cumulative exposure to environmental pollutants during early pregnancy and reduced fetal growth: the Project Viva cohort

Study Purpose: To examine interactions between early pregnancy exposure to cigarette smoke, traffic pollution, and PFAS on birth weight for gestational age.

Study Conclusion: Prenatal exposure to PFOS was associated with lower fetal growth.

Prenatal Exposure to Perfluoroalkyl Substances: Infant Birth Weight and Early Life Growth

Study Purpose: To determine if prenatal PFAS exposure was associated with birth weight, body composition and growth until 2 years of age.

Study Conclusion: The study observed inverse associations between prenatal serum PFAS concentrations and anthropometry until age 2 years. Prenatal serum PFAS concentrations were not associated with growth rate in the first 2 years of life.

Gestational exposure to endocrine disrupting chemicals in relation to infant birth weight: a Bayesian analysis of the HOME Study

Study Purpose: To examine the association of gestational exposure to endocrine disrupting chemicals, including PFAS.

Study Conclusion: Gestational exposure to PFAS had small associations with birth weight.          

Prenatal exposure to perfluoroalkyl substances and birth outcomes in a Spanish birth cohort

Study Purpose: To estimate associations between prenatal PFAS exposure and birth outcomes, and the influence of kidney factors, in a birth cohort.

Study Conclusion: PFAS showed little association with birth outcomes. Higher PFHxS, PFOA, and PFNA were associated with reduced birth weight. The association between PFOS and low birth weight seems to be sex-specific.

Maternal Concentrations of Perfluoroalkyl Substances and Fetal Markers of Metabolic Function and Birth Weight

Study Purpose: To examine associations between first-trimester maternal plasma PFAS concentrations and birth weight.

Study Conclusion: All associations between maternal PFAS concentrations and cord blood adipocytokine concentrations were small.

Other

Mixtures of persistent organic pollutants are found in vital organs of late gestation human fetuses

Study Purpose: This study measured persistent organic pollutants, such as PFAS, in maternal serum, placenta, and fetal tissues in 20 pregnancies that ended in stillbirth.

Study Conclusion: This study quantified many POPs in fetal tissues. All studied chemicals were detected in fetal adipose tissue even in places when the chemical was not detected in the maternal serum and placenta.

A case-cohort study of perinatal exposure to potential endocrine disrupters and the risk of cryptorchidism in the Norwegian HUMIS study

Study Purpose: Exposure to PFAS and other endocrine-disrupting chemicals (EDCs) during the critical period of testicular descent may increase the risk of cryptorchidism and male fertility. The objective of this study was to investigate 27 potential EDCs in breast milk and the risk of cryptorchidism.

Study Conclusion: Perinatal exposure to PCB-74, PCB-114, PCB-194, and B-HCH were associated with increased odds of congenital cryptorchidism.

Exposure to endocrine disrupting chemicals (EDCs) and cardiometabolic indices during pregnancy: The HOME Study

Study Purpose: Toxicology studies have identified pregnancy as a time sensitive to endocrine disrupting chemicals (EDCs), such as PFAS, and cardiometabolic indices in women. No study has examined this in humans.

Study Conclusion: Overall, there were positive associations between PBDEs with glucose and cholesterol levels during pregnancy, while negative associations were found between some phthalates and cholesterol. No relationship was noted for BPA or PFAS with cardiometabolic indices during pregnancy across both models.

Associations of single and multiple per- and polyfluoroalkyl substance (PFAS) exposure with vitamin D biomarkers in African American women during pregnancy

Study Purpose: Vitamin D has been linked to various physiological function in pregnant women and their fetuses. This study aims to evaluate the associations of PFAs levels with vitamin D levels during pregnancy in a cohort of African American women in Atlanta.

Study Conclusion: This study suggests that exposure to PFAs might disturb vitamin D metabolism among pregnant African American women and that some of these effects might be changed by the sex of the fetus. More studies are needed to confirm these findings.

Association between maternal exposure to perfluoroalkyl and polyfluoroalkyl substances and risks of adverse pregnancy outcomes: A systematic review and meta-analysis

Study Purpose: This reviews and analyzes previous studies on the relationship of maternal PFAS exposure and adverse pregnancy outcomes.

Study Conclusion: It was found that maternal exposure to PFOS could be positively associated with preterm birth, while no statistically significant association have been found between PFASs exposure and miscarriage and stillbirth. Epidemiological evidence to date are insufficient to draw definitive conclusions on potential toxicities of PFASs with stronger statistical power.

Associations of single and multiple per- and polyfluoroalkyl substance (PFAS) exposure with vitamin D biomarkers in African American women during pregnancy

Study Purpose: Vitamin D has been linked to various physiological function in pregnant women and their fetuses. This study aims to evaluate the associations of PFAs levels with vitamin D levels during pregnancy in a cohort of African American women in Atlanta.

Study Conclusion: This study suggests that exposure to PFAs might disturb vitamin D metabolism among pregnant African American women and that some of these effects might be changed by the sex of the fetus. More studies are needed to confirm these findings.

Maternal exposure to perfluoroalkyl chemicals and anogenital distance in the offspring: a Faroese cohort study

Study Purpose: Exposure to PFASs has in some studies been associated with reduced anogenital distance in newborns, an indicator of prenatal anti-androgenic exposure. The aim of this study was to investigate the association between maternal PFAS exposure and offspring anogenital distance in a population with wide ranges of PFAS exposures.

Study Conclusion: In conclusion, we found that maternal PFAS exposure was significantly associated with a longer AGDs in boys. No significant associations were found among girls, suggesting sex-dimorphic effects of PFASs. Whether the observed association with longer ASD and PFAS influences the reproductive health of males is unknown and needs to be investigated further.

Prenatal exposures to mixtures of endocrine disrupting chemicals and children's weight trajectory up to age 5.5 in the SELMA study

Study Purpose: This study evaluates the effect of prenatal exposure to mixtures of endocrine disrupting chemical (such as PFASs) mixtures on birthweight and childhood weight trajectories.

Study Conclusion: Prenatal exposure to EDC mixtures was associated with lower birthweight and altered infant weight gain trajectories.

Exposure to perfluoroalkyl substances in early pregnancy and risk of sporadic first trimester miscarriage

Study Purpose: The aim of this study was to investigate whether PFASs in early pregnancy are associated with unexplained, sporadic first trimester miscarriage.

Study Conclusion: There was an association between PFOA and miscarriage in this study. The study can only represent early placentation and clinical pregnancy loss during the second half of the first trimester.

Perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) and DNA methylation in newborn dried blood spots in the Upstate KIDS cohort

Study Purpose: PFOA and PFOS may alter prenatal development, through modifying DNA. Prior studies on this subject have had few subjects and inconsistent results. This study examines relationships between PFOA and PFOS with DNA changes among nearly 600 infants.

Study Conclusion: There was limited evidence of an association between high concentrations of PFOA/PFOS and DNA changes in newborns in this study. Future studies are needed in populations with higher concentrations of PFOA/PFOS.

Prenatal Exposure to Per- and Polyfluoroalkyl Substances, Umbilical Cord Blood DNA Methylation, and Cardio-Metabolic Indicators in Newborns: The Healthy Start Study

Study Purpose: This study looks at the associations between prenatal PFAS exposure and changes in DNA in umbilical cord blood.

Study Conclusion: DNA changes in umbilical cord blood were associated with maternal PFAS concentrations during pregnancy, which could affect offspring growth, metabolism, and immune function.

Per- and polyfluoroalkyl substance mixtures and gestational weight gain among mothers in the Health Outcomes and Measures of the Environment study

Study Purpose: This study looks at associations between PFAS exposure and gestational weight gain.

Study Conclusion: Although there were consistent small increases in gestational weight gain with increasing PFOA, PFOS, and PFNA serum concentrations in this cohort, the associations were imprecise. Additional investigation of the association of PFAS with GWG in other cohorts would be informative and could consider pre-pregnancy BMI as a potential modifier.

Perfluoroalkyl substances exposure in early pregnancy and preterm birth in singleton pregnancies: a prospective cohort study

Study Purpose: To investigate the associations between prenatal PFAS exposure and preterm birth among singleton live births.

Preeclampsia and hypertensive disorders of pregnancy

Per- and Poly-fluoroalkyl Substances and Bile Acid Profiles in
Pregnant Women

Study Purpose: Alterations in bile acid (BA) profiles are closely associated with adverse outcomes in pregnant women and their offspring and may be one potential pathway underlying the related metabolic effects of per- and poly-fluoroalkyl substances (PFAS) exposure.

Study Conclusion: Our findings provide the first epidemiological evidence for the associations of a PFAS mixture with BA profiles in pregnant women and may provide explanatory insights into the biological pathways underlying the related metabolic effects of PFAS exposure.

Perfluoroalkyl and polyfluoroalkyl substances and hypertensive disorders of pregnancy: A systematic review and meta-analysis

Study Purpose: Hypertensive disorders of pregnancy (HDP), including gestational hypertension and preeclampsia, may be partially attributed to environmental toxins. This study reviews the evidence of associations between PFAS and HDP.

Study Conclusion: This study provides low to moderate certainty evidence of associations between PFOA, PFOS, and PFHxS exposure and the risk of pre-eclampsia. The certainty of evidence for an association between PFOS and HDP was considered low. 

In utero exposure to per-/polyfluoroalkyl substances (PFASs): Preeclampsia in pregnancy and low birth weight for neonates

Study Purpose: PFAS have been linked to preeclampsia with inconsistent findings. However, information regarding the joint effects of PFAS mixtures on preeclampsia as well as their associations with low birth weight (LBW) and small for gestational age (SGA) is not well studied. The present study included 82 women with preeclampsia and 169 healthy participants from China.

Study Conclusion: Several PFAS were associated with higher odds of preeclampsia, while some others showed a reverse trend. Overall, the analysis suggested that combined PFAS exposure increased the risks for the development of preeclampsia. We observed that PFOA and PFUnDA were significantly associated with increased odds of early-onset preeclampsia, while it was not the case in late-onset. Whether early-onset preeclampsia is particularly at higher risks for PFASs exposure and might induce adverse fetal outcomes deserved in-depth exploration. With regard to neonatal development, negative associations were observed between birth weight and PFNA, PFUnDA, PFOS and 6:2Cl-PFESA exposure. Higher risks of low birth weight and small for gestational age were associated with preeclampsia and PFOA exposure. 

Exposure to endocrine-disrupting chemicals and risk of gestational hypertension and preeclampsia: A systematic review and meta-analysis

Study Purpose: Prenatal exposure to PFAs has been linked to gestational hypertension and preeclampsia, though some results have been conflicting. This paper reviews the findings of studies on these relationships.

Study Conclusion: Since most of these associations have limited evidence, more research is needed to confirm these findings.

Associations of perfluoroalkyl and polyfluoroalkyl substances with gestational hypertension and blood pressure during pregnancy: A cohort study

Study Purpose: This study aimed to evaluate effects of PFAS on gestational hypertension (GH) and blood pressure measures throughout pregnancy.

Study Conclusion: This study found that high concentrations of PFAS in early pregnancy were associated with decreased risk of gestational hypertension and reduced longitudinal blood pressure measures in the third trimester, which may reflect the effect of PFAS at relatively high exposure levels. This may vary by the sex of the baby.

Early-pregnancy plasma per- and polyfluoroalkyl substance (PFAS) concentrations and hypertensive disorders of pregnancy in the Project Viva cohort

Study Purpose: Hypertensive disorders of pregnancy (HDP) affect up to 10% of pregnancies in the United States and are associated with substantial maternal and neonatal morbidity and mortality. Per- and polyfluoroalkyl substances (PFAS) are associated with adverse cardiometabolic outcomes during pregnancy, but associations between PFAS and HDP are inconsistent and joint effects of PFAS mixtures have not been evaluated.

Study Conclusion: These findings suggest that exposure to certain PFAS may increase the odds of gestational hypertension during pregnancy.

Per- and polyfluoroalkyl substances in drinking water and hypertensive disorders of pregnancy in the United States during 2013-2015

Study Purpose: This study investigates the associations between PFAS and hypertensive disorders of pregnancy.

Study Conclusion: There was a weak positive association between the PFAS mixture and hypertensive disorders of pregnancy, although there are limitations as this was public data.

Endocrine-Disrupting Chemical Exposures in Pregnancy: a Sensitive Window for Later-Life Cardiometabolic Health in Women

Study Purpose: Pregnancy can be seen as a "stress test" with complications predicting later-life cardiovascular disease risk. Here, we review the growing epidemiological literature evaluating environmental endocrine-disrupting chemical (EDC) exposure in pregnancy in relation to two important cardiovascular disease risk factors, hypertensive disorders of pregnancy and maternal obesity.

Study Conclusion: Although numerous studies evaluated pregnancy outcomes, few evaluated the postpartum period or assessed chemical mixtures. Overall, there is a need to better understand whether pregnancy exposure to these chemicals could contribute to adverse cardiometabolic health outcomes in women, particularly given that cardiovascular disease is the leading cause of death in women.

Maternal Levels of Perfluoroalkyl Substances (PFAS) during Early Pregnancy in Relation to Preeclampsia Subtypes and Biomarkers of Preeclampsia Risk

Study Purpose: This study examines the associations between PFAS, any preeclampsia diagnosis, and early- and late-onset preeclampsia. In addition, they estimate associations between PFAS and biomarkers that provide an estimate of pro- and anti- angiogenic activity within the placenta.

Study Conclusion: Maternal PFAS concentrations were associated with higher odds of late-onset preeclampsia. Differences in preeclampsia should be considered in future studies because populations may have different distributions of disease subtypes.

Exposure to perfluoroalkyl substances in early pregnancy and the risk of hypertensive disorders of pregnancy: A nested case-control study in Guangxi, China

Study Purpose: Previous studies have examined the associations between exposure to PFAS and the risk of hypertensive disorders of pregnancy. However, these studies have had some limitations. This study again addresses this association.

Study Conclusion: This study found that combined exposure to nine PFAS had a positive effect on the development of hypertensive disorders of pregnancy (HDP). PFOS and PFBS were positively associated with HDP risk, while PFHxS and PFHpA were negatively associated with the HDP risk in women in Guangxi, China.

Considering Environmental Exposures to Per- and Polyfluoroalkyl Substances (PFAS) as Risk Factors for Hypertensive Disorders of Pregnancy

Study Purpose: This reviews the literature on associations between PFAS and hypertensive disorders of pregnancy and recommends next steps for research and prevention.

Study Conclusion: Positive associations between 6 PFASs--PFOA, PFOS, PFHxS, PFHpA, PFBS, and PFNA-- and risk for HDP have been reported in some studies, though these associations have not been seen in other studies.

Exposure to perfluoroalkyl substances and blood pressure in pregnancy among 1436 women from the Odense Child Cohort

Study Purpose: This study investigates the association between PFAS exposure in early pregnancy and maternal blood pressure throughout pregnancy, gestational hypertension, and preeclampsia.

Study Conclusion: The strength of the relationship between PFAS exposure blood pressure may appear small. However, at a population level this may slightly shift the distribution of blood pressure towards an increased incidence of gestational hypertension. If blood pressure increases in pregnancy, it may have a long-term impact on health not only of the pregnant woman but also of her offspring.

Exposure to toxic metals and per- and polyfluoroalkyl substances (PFAS) and the risk of preeclampsia and preterm birth in the United States: A review

Study Purpose: This article reviews past studies to provide an overview on environmental contaminants (such as PFAS) and the development of preeclampsia and preterm birth among U.S. women.

Study Conclusion: There are inconsistent findings on the relationship between PFASs and preeclampsia and preterm birth.

Per- and Polyfluoroalkyl Substances in Early Pregnancy and Risk for Preeclampsia: A Case-Control Study in Southern Sweden

Study Purpose: To investigate the association between serum concentrations of PFAS in early pregnancy and the risk of developing preeclampsia.

Study Conclusion: This study provides limited support for the association between PFAS and preeclampsia in a population with relatively low exposure levels.

Study Conclusion: There were no associations between maternal PFAS levels in early pregnancy and infant length, preterm birth, or spontaneous or indicated preterm birth.

Association of perfluoroalkyl substances with gestational hypertension and preeclampsia in the MIREC study

Study Purpose: To examine the relationship between background levels of PFOA, PFOS, and PFHxS and the development of gestational hypertension or preeclampsia in a Canadian pregnancy cohort.

Study Conclusion: Higher levels of PFHxS were associated with the development of preeclampsia, but not gestational hypertension. Both PFOA and PFOS were not associated with either outcome.

Perfluoroalkyl substances in early pregnancy and risk of hypertensive disorders of pregnancy: A prospective cohort study

Study Purpose: This study looks at associations between PFAS exposure and hypertensive disorders of pregnancy.

Study Conclusion: Maternal levels of PFASs in early pregnancy were not associated with gestational hypertension, preeclampsia, or hypertensive disorders of pregnancy.

Early pregnancy serum levels of perfluoroalkyl substances and risk of preeclampsia in Swedish women

Study Purpose: To investigate the association between early pregnancy serum levels of PFAS and preeclampsia.

Study Conclusion: Increasing serum levels of PFOS and PFNA during early pregnancy were associated with a clinically relevant risk of preeclampsia, adjusting for established confounders.

Prenatal exposure to perfluoroalkyl and polyfluoroalkyl substances and the risk of hypertensive disorders of pregnancy

Study Purpose: PFAS have been reported to disrupt the endocrine system and reproductive system, but information on the association between PFAS and preeclampsia is not consistent. This study looks at the association between prenatal PFAS exposure and hypertensive disorders of pregnancy.

Study Conclusion: Prenatal exposure to PFBS was associated with elevated risk of preeclampsia and hypertensive disorders of pregnancy.

Fertility and treatment

PFAS exposure exert negative effects on oocyte
yield, fertilization and high-quality embryo in women
undergoing IVF

Study Purpose: As part of standard Assisted Reproductive Technology (ART) procedures, both the treatment results and collected samples present valuable prospects for exploring the connection between PFAS levels and In Vitro Fertilization (IVF) results, which may provide insights into the potential impact of PFAS on female
reproductive health. Previous studies primarily examined individual PFAS and did not
investigate the possible combined impact of PFAS mixtures on human reproductive capabilities. To address these gaps in existing research, this study aimed to assess the links between plasma levels of individual PFAS and PFAS mixtures in women undergoing IVF-ET and how these exposures might affect female reproductive health. 

Study Conclusion: Blood samples were collected over the first three days of a woman's menstrual cycle to analyze the foundational hormone profiles, which comprised follicular-stimulating-hormone (FSH), luteal hormone (LH), and estradiol (E2).

Environmental Exposure to Emerging Alternatives of Per- and Polyfluoroalkyl Substances and Polycystic Ovarian Syndrome in Women Diagnosed with Infertility: A Mixture Analysis

Study Purpose: PFAS have been previously linked to polycystic ovarian syndrome (PCOS), but this has only been assessed in a few PFAS. This study aimed to explore this association with a variety of PFAS, including emerging alternatives, as well as PFAS mixtures. 

Study Conclusion: In this study population, exposure to PFAS mixtures was associated with elevated odds of PCOS, with 6:2 Cl-PFESA, HFPO-DA, uppercase sigma 3,4,5 lowercase m-uppercase p f o sΣ3,4,5m-PFOS, and PFDoA being the major contributors, especially in overweight or obese women.

Perfluoroalkyl Acids in Follicular Fluid and Embryo Quality during IVF: A Prospective IVF Cohort in China

Study Purpose: There are few human studies that have demonstrated a link between exposure to PFAS and decreased fertility. This study assessed the associations between preconception plasma PFAS concentrations and fertility outcomes in women.

Study Conclusion: Higher PFAS exposure may be associated with decreased fertility in women. The mechanisms behind this relationship need further study.

Perfluoroalkyl Acids in Follicular Fluid and Embryo Quality during IVF: A Prospective IVF Cohort in China

Study Purpose: PFAS have been measured in follicular fluid from women undergoing IVF, although associations between follicular fluid PFAS levels and IVF outcomes have been inconsistent. This study investigated the association between follicular fluid PFAS levels and embryo quality in women undergoing IVF.

Study Conclusion: Higher PFAS levels in follicular fluid were associated with poorer embryo quality during IVF. Branched PFOS isomers may have a stronger effect than linear PFOS isomers. More studies are needed to confirm these findings and to directly estimate the effects on pregnancy and live-birth outcomes. 

The effects of perfluoroalkyl and polyfluoroalkyl substances on female fertility: A systematic review and meta-analysis

Study Purpose: The reproductive toxicity of PFAS has been shown in animal experiments, however, the association between PFAS and female fertility remains contradictory in population studies. This review evaluates the effects of PFAS on female fertility based on population evidence.

Study Conclusion: Based on the evidence provided by the current study, increased levels of PFAS exposure are associated with reduced fertility in women, this was characterized by a reduction in fecundability odds and an increase in odds for infertility. This finding could partially explain the decline in female fertility and provide insight into risk assessment when manufacturing products containing PFAS.

Association between chemical mixtures and female fertility in women undergoing assisted reproduction in Sweden and Estonia

Study Purpose: Women of reproductive age are exposed to chemicals such as phthalates, parabens, and PFAS, which may affect fertility. The objective of this study was to investigate associations between potential endocrine disrupting chemicals (EDCs), including PFAS, and female fertility in two cohorts of women attending fertility clinics.

Study Conclusion: This study provided evidence supporting the presence of and an inverse association between DEHP metabolites and female fertility and identifying chemicals such as methylparaben, and possibly PFUnDA and PFOA, that can be involved in the biological processes causing female infertility via disruption of ovarian function.

Mixtures of persistent organic pollutants and ovarian function in women undergoing IVF

Study Purpose: This study investigates whether internal levels of persistent organic pollutants (POPs)--such as PFAS--in serum and follicular fluid affect ovarian function of women undergoing IVF.

Study Conclusion: Globally, associations between POP and the markers of ovarian function or responsiveness were lacking. Nonetheless, the stratification analysis suggested that current smoking could be a risk modifier, and extension of the study to a larger population sample size is needed.

Associations between internal concentrations of fluorinated and organochlorinated chemicals in women and in vitro fertilization outcomes: A multi-pollutant study

Study Purpose: The impact of persistent pollutants on reproductive health is poorly understood. This study aims to characterize the internal levels of PCBs, OCPs, and PFAS in women undergoing IVF and evaluate their association with IVF outcomes.

Study Conclusion: The results showed that mixtures of low concentrations of PCBs, OCPs, and PFAS are widespread among women. Most pollutants were not associated with IVF outcomes, like live birth rate. Further study is needed.

Per- and polyfluoroalkyl substances (PFAS) exposure in women seeking in vitro fertilization-embryo transfer treatment (IVF-ET) in China: Blood-follicular transfer and associations with IVF-ET outcomes

Study Purpose: Follicular fluid is a critical environment for the development of oocytes, so investigation of environmental contaminants in follicular fluid may facilitate a better understanding of the influence of environmental exposure on reproductive health. In this study, they aim to investigate PFAS exposure in women receiving in vitro fertilization-embryo transfer (IVF-ET) treatment, determine the blood-follicle transfer efficiencies (BFTE) of PFAS, and explore potential associations between PFAS exposure and selected IVF-ET outcomes.

Study Conclusion: In the present study, we measured a suite of PFAS chemicals in paired blood and follicular fluid collected from women receiving the IVF-ET treatments through a prospective cohort study. Our results reveal the frequent detection of several legacy and emerging PFAS in the study population, suggesting broad exposure. A number of PFAS exhibited high potency to cross the blood-follicle barrier, and the BFTE may be partially affected by their physicochemical properties such as Kow, although other influencing factors could also exist. Although our data did not find any significant association between blood or follicular fluid concentrations of PFAS and selected IVF-ET outcomes, our study raises the need of better characterization of follicular exposure to environmental chemicals and potential influence on reproductive health.

Follicular fluid and blood levels of persistent organic pollutants and reproductive outcomes among women undergoing assisted reproductive technologies

Study Purpose: Persistent organic pollutants (POPs), such as PFAS, are chemicals resistant to degradation. This study measured POP levels in women who were seeking fertility treatment.

Study Conclusion: These results suggest that age plays a role in the chemical transfer from blood to follicular fluid and that exposure to POPs is associated with fertility treatment outcomes.

Associations between human internal chemical exposure to Persistent Organic Pollutants (POPs) and In Vitro Fertilization (IVF) outcomes: Systematic review and evidence map of human epidemiological evidence

Study Purpose: The aim of this study was to review the evidence on associations between internal levels of persistent organic pollutants, such as PFAs, and IVF outcomes among women.

Study Conclusion: The review showed that many types of persistent pollutants (POPs) are in follicular fluid and serum of women attending IVF treatments. Globally, there were inconsistent findings across studies for specific exposure-outcome dyads, suggesting that adverse effects of POPs on IVF outcomes cannot be ruled out. These results suggest that POPs may impair embryo quality and pregnancy rates.

Perfluoroalkyl Chemicals and Male Reproductive Health: Do PFOA and PFOS Increase Risk for Male Infertility?

Study Purpose: This review looks at previous studies on PFOS/PFOA effects on male reproductive health.

Study Conclusion: Human and rodent studies suggest that increased PFAS exposure could be associated with changes in some enzymes, including gonadal or serum testosterone, testicular receptors for gonadotropin, growth hormone, and IGF-1 and semen parameters.

Endocrine disrupting chemicals: Impacts on human fertility and fecundity during the peri-conception period

Study Purpose: The goals of this study include:

  1. Identify and review evidence regarding the effects of endocrine-disrupting chemicals on adult male and female fertility, reproductive hormone concentrations, gamete and embryo characteristics, as well as the time to pregnancy
  2. To investigate whether individuals or couples diagnosed as sub-fertile have higher endocrine-disrupting chemical levels
  3. To highlight where little or no data exists that prevents associations from being identified.

Study Conclusion: Currently, the findings from human studies do not support a consistent effect of PFAS on male fertility. No association is evident from animal studies. For women, nearly all measured fertility results had conflicting findings. Few animal studies have been conducted regarding female fertility and PFAS exposure.

Persistent organic pollutants and couple fecundability: a systematic review

Study Purpose: To summarize the strength of evidence for associations of four common groups of persistent organic pollutants and a couple's probability to conceive. To identify gaps and limitations in the literature in order to inform policy decisions and future research.

Study Conclusion: This review found no support for associations between female exposure to pesticides or male exposure to any persistent organic pollutant's groups and time to pregnancy.

Parental plasma concentrations of perfluoroalkyl substances and In Vitro fertilization outcomes

Study Purpose: This study looks at whether maternal or paternal PFAS levels have effects on in vitro fertilization (IVF) outcomes.

Study Conclusion: These results suggest that PFAS may have reproductive effects on both men and women, and that exposure to PFAS may negatively affect IVF outcomes.

Per- and poly-fluoroalkyl substances (PFASs) in follicular fluid from women experiencing infertility in Australia

Study Purpose: This study investigates if associations exist between PFAS concentrations, age, and fertilization rate. This study also investigates the associations between PFAS concentrations and infertility.

Study Conclusion: PFASs were detected in follicular fluid of Australian women who had been treated at an IVF clinic. This study found that PFAS in follicular fluids was linked to an increased risk of some infertility factors. Increased age was associated with decreased fertilization rate. There was no relationship between PFAS and fertilization rate.   

Perfluoroalkyl substances and endometriosis-related infertility in Chinese women

Study Purpose: To examine the association between PFASs and endometriosis-related infertility.

Study Conclusion: Exposure to PFBS may increase the risk of female infertility due to endometriosis.

Perfluoroalkyl and polyfluoroalkyl substances and measures of human fertility: a systematic review

Study Purpose: To review current evidence on the association between exposure to PFASs and measures of human fertility.

Study Conclusion: For PFOS and PFOA, the literature indicates an association with female fertility in women who have had children.

Women’s Health

Early menarche and other endocrine disrupting effects of per- and polyfluoroalkyl substances (PFAS) in adolescents from Northern Norway. The Fit Futures study

Study Purpose: The aim of this study was to investigate associations of various PFAS with thyroid, parathyroid, steroid and sex hormones, as well as with menstrual function and pubertal development in teenagers recruited from the general population of Northern Norway.

Study Conclusion: Serum concentrations of several PFAS were associated with parathyroid and steroid hormones in both sexes, and with thyroid hormones in boys, as well as with early menarche in girls and higher PDS in boys.

Environmental exposure to legacy and emerging per- and polyfluoroalkyl substances and endometriosis in women of childbearing age

Study Purpose: In the present study, we investigated (i) whether single PFAS exposure was associated with endometriosis; (ii) whether PFAS mixture has a
joint effect on endometriosis; and (iii) which PFAS was the dominant contributor. 

Study Conclusion: Our study suggests that PFAS exposure is associated with an
increased odds of endometriosis. The branched isomer of PFOS, i.e., 1mPFOS, is the dominant contributor, suggesting that emerging PFAS (isomers, precursors and alternatives) warrants further research. Considering the wide-ranging PFAS exposure in women of childbearing age, our findings may have significant public health implications. More studies are needed to confirm or refute our results and to elucidate the underlying mechanisms. 

Trimester-specific hemodynamics of per- and polyfluoroalkyl substances and its relation to lipid profile in pregnant women

Study Purpose: PFAS can be detected in the blood of pregnant women, but the effects of pregnancy on blood volume may affect PFAS measurements by trimester. Additionally, little is known on specific windows during pregnancy where PFAS may interrupt cholesterol metabolism. In this study, PFAS and cholesterol measures were obtained in pregnant women.

Study Conclusion: PFAS levels showed a decline in maternal blood samples during pregnancy, except for PFTrDA. 

Associations of Pregnancy Per- and Polyfluoroalkyl Substance Concentrations and Uterine Fibroid Changes across Pregnancy: NICHD Fetal Growth Studies - Singletons Cohort

Study Purpose: Fibroids often undergo changes during pregnancy. Because PFAS disrupt hormonal signaling, they may affect fibroid growth. This study assesses associations between PFAS and fibroid changes in pregnancy.

Study Conclusion: In this study, prenatal levels of certain PFAS were associated with both first-trimester total fibroid volume and total fibroid volume trajectory across pregnancy. Because PFAS were not associated with the number of fibroids, PFAS may primarily influence volume change in fibroids rather than contributing to fibroid formation.

An exposure to endocrine active persistent pollutants and endometriosis - a review of current epidemiological studies

Study Purpose: Widespread exposure to persistent organic pollutants (POPs) can disrupt natural endocrine functions and contribute to reproductive diseases such as endometriosis. This review focuses on the relationship between several POPs, including PFAS, and risk of endometriosis.

Study Conclusion: In conclusion, the results of the reviewed studies suggest that exposure to POPs may be associated with the occurrence of endometriosis. The consistent results were found in the case of all described organochlorine pesticides (OCPs), lead, and PCBs. The results of the studies on mercury, cadmium, copper, chromium, zinc, PCB-52, PCB-101, PCB-118, PCB-138, PCB-156, PCB-180, 2,3,7,8— TCDD, OCDF, PBB-77, PBB-101, PBB-153, PBB-180, PBDE-47, PBDE-183, PFOA, PFNA, PFBS, and PFOS exposure are inconclusive. Due to conflicting results, further study is needed to confirm these findings.

Association between Perfluoroalkyl and Polyfluoroalkyl Substances and Women's Infertility, NHANES 2013-2016

Study Purpose: The role of PFAS in infertility is poorly understood. This study included 788 women to explore the association between PFAS exposure and self-reported infertility.

Study Conclusion: This study found that associations with PFAS and women's infertility varied according to types of PFAS and age. There was a non-linear association between PFAS and women's infertility. Mixed PFAS exposure might influence infertility negatively as revealed in the BKMR model. Our study indicated that further profound studies are needed to address the impact of low-dose PFAS exposure on women’s infertility.

Endocrine disrupting chemicals impact on ovarian aging: Evidence from epidemiological and experimental evidence

Study Purpose: It is important to summarize the impacts of endocrine disrupting chemicals (EDCs), such as PFAS, on ovarian aging. This review focuses on the impacts of 10 environmental contaminants on the progression of ovarian aging during adult exposure, including epidemiological data in humans and experimental models in rodents, with their clinical phenotypes and underlying mechanisms.

Study Conclusion: Most epidemiological evidence demonstrated that both persistent (PFASs and PCBs) and non-persistent EDCs (phthalates) exposure could increase the overall risk of ovarian aging, leading to DOR (diminished ovarian reserve), fertility or fecundity decline, menstrual cycle irregularity and an earlier age at menopause, due to the accelerated follicles loss and endocrine disorder.

Perfluoroalkyl Substances and Incident Natural Menopause in Midlife Women: The Mediating Role of Sex Hormones

Study Purpose: PFAS exposure has been associated with earlier natural menopause; however, the underlying mechanisms are not well understood, or how the relationship is affected by sex hormones. This study investigates the relationship between PFAS and menopause and how the relationship may be affected by sex hormones.

Study Conclusion: In conclusion, this study is the first to investigate and quantify the degree to which FSH is an explanatory factor for the shortened time to natural menopause in midlife women with higher exposure to PFAS. Although mediation analysis still does not concretely establish a causal pathway, our findings provide evidence that PFAS exposure may accelerate ovarian aging through endocrinologic mechanisms associated with changing serum concentrations of FSH. Any potential mechanism underlying the relationships between PFAS exposure and natural menopause is likely to involve an interplay of hormones, beyond the action of single hormone levels. Future replication of our findings should consider other hormones such as luteinizing hormone in the analysis.

Per- and Poly-fluoroalkyl Substances (PFAS) and Female Reproductive Outcomes: PFAS Elimination, Endocrine-Mediated Effects, and Disease

Study Purpose: This paper summarizes the role of PFAS in female reproductive tract dysfunction and disease. Since these chemicals can affect reproductive tissue, this is also discussed.

Study Conclusion: Given the global decline in female fertility and the ability of PFAS to negatively impact female reproductive health, further studies are needed to examine effects on women.

Perfluoroalkyl substances (PFAS) in drinking water and risk for polycystic ovarian syndrome, uterine leiomyoma, and endometriosis: A Swedish cohort study

Study Purpose: PFAS may interfere with the female reproductive system. The aim of this study is to investigate possible associations between PFAS exposure and PCOS, uterine leiomyoma, and endometriosis.

Study Conclusion: Exposure to high levels of PFAS in drinking water was associated with increased risk of PCOS and possibly uterine leiomyoma, but not endometriosis. The findings for PCOS are consistent with prior studies reporting positive associations between PCOS and PFAS exposure at background levels.

Association between maternal exposure to perfluoroalkyl and polyfluoroalkyl substances and risks of adverse pregnancy outcomes: A systematic review and meta-analysis

Study Purpose: This reviews and analyzes previous studies on the relationship of maternal PFAS exposure and adverse pregnancy outcomes.

Study Conclusion: It was found that maternal exposure to PFOS could be positively associated with preterm birth, while no statistically significant association have been found between PFASs exposure and miscarriage and stillbirth. Epidemiological evidence to date are insufficient to draw definitive conclusions on potential toxicities of PFASs with stronger statistical power.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) and their effects on the ovary

Study Purpose: To review the available literature for correlations between PFAS exposure and ovarian function.

Study Conclusion: The published literature supports associations between PFAS exposure and adverse reproductive outcomes; however, the evidence remains insufficient to infer a causal relationship between PFAS exposure and ovarian disorders.

Quantitative bias analysis of a reported association between perfluoroalkyl substances (PFAS) and endometriosis: The influence of oral contraceptive use

Study Purpose: To evaluate the influence of oral birth control use on the association between PFAS and endometriosis.

Study Conclusion: Study results suggest that the influence of oral contraceptive use on the association between PFAS levels and endometriosis is relatively small.

Endocrine-disrupting chemicals and uterine fibroids

Study Purpose: A useful summary of the known literature showing associations between environmental exposure to endocrine disrupting chemicals and uterine fibroids.

Study Conclusion: Delineating the effects of EDC exposure and the underlying mechanisms by which they, or other environmental exposures, promote MSC progression to UFs, including the role of epigenetic alterations and acquisition of mutations in genes such as MED12, will be key to the development of new interventions to prevent and treat this important disease of women.

Perfluoroalkyl substances and endometriosis in US women in NHANES 2003-2006

Study Purpose: To examine the relationship between PFAS and endometriosis.       

Study Conclusion: These findings suggest that PFOA, PFNA, and PFOS may be of interest in future studies with improved endometriosis diagnostic criteria and prospectively measured exposure.

Placenta

PFOS Impairs Mitochondrial Biogenesis and Dynamics and Reduces Oxygen Consumption in Human Trophoblasts

Study Purpose: This study aimed to examine the role of mitochondrial dynamics and biogenesis in trophoblasts exposed to PFOS. We hypothesized that PFOS disrupts the expression of genes associated with biogenesis and dynamics, leading to mitochondrial dysfunction.

Study Conclusion: Findings indicate that exposure to PFOS may impair the bioenergetic capacity of trophoblasts by reducing OCR associated with basal and ATP-linked respiration. Additionally, PFOS exposure downregulates the expression of genes involved in mitochondrial fission, fusion, and biogenesis in trophoblasts.

Evaluating the Effect of Gestational Exposure to Perfluorohexane Sulfonate on Placental Development in Mice Combining Alternative Splicing and Gene Expression Analyses.

Study Purpose: Perfluorohexane sulfonate (PFHxS) is a frequently detected per- and polyfluoroalkyl substance in most populations, including in individuals who are pregnant, a period critical for early life development. Despite epidemiological evidence of exposure, developmental toxicity, particularly at realistic human exposures, remains understudied. The objectives of the current study were to investigate exposure of mice to human-relevant doses (0.03 and 0:3lg=kg=day ) of PFHxS, orders of magnitude lower thanPFOS (2:5mg=kg=day, a dose which decreased placenta size and fetal weight)orPFOA(5mg=kg=day, a dose which impaired follicle development in mice), and its toxic effect on fetal development as well as the potential toxicological mechanisms underlying placenta impairment in mice.

Study Conclusion: The findings from this study suggest that exposure to human relevant very low dose PFHxS during pregnancy in mice caused IUGR. Via downregulating of placental amino acid transporters, impairing placental amino acid transportation, resulting in impairment of placental development.

Low transplacental transfer of PFASs in the small-for-gestational-age (SGA) new-borns: Evidence from a Chinese birth cohort

Study Purpose: In this study, 30 PFAS were measured in pregnant mothers and in cord serum from 195 births to understand transfer of PFAS from mom to offspring.

Study Conclusion: These results show that there were differences in transfer of PFAS across the placenta between small for gestational age and appropriate for gestational age offspring, with small for gestational age groups having PFAS not transferred as much across the placenta as the appropriate for gestational age group.

The transplacental transfer efficiency of per- and polyfluoroalkyl substances (PFAS): a first meta-analysis

Study Purpose: The aim of this study was to provide a review of literature on PFAS transfer rates across the human placental barrier by means of a meta-analysis based on systematic review.

Study Conclusion: The results of this study showed that PFAS with sulfonyl groups are transferred less efficiently than those containing carboxyl groups. Less well studied PFAS such as PFHxA, 6:2 FTS, and PFBA are highly efficiently transported across the placental barrier, suggesting that PFAS with a more complex structure may also enter the fetal circulation. The potential consequences for fetal health need to be further investigated, as these compounds are increasingly used, but their mode of action is poorly understood.

Placental Transfer and Composition of Perfluoroalkyl Substances (PFASs): A Korean Birth Panel of Parent-Infant Triads

Study Purpose: In this study, they measured PFAS concentrations in maternal, paternal, and umbilical cord serum collected from 62 pregnant women and their matched biological fathers. Placental transfer rates of PFAS were calculated.

Study Conclusion: The results of this study showed different concentrations and types of PFAS among maternal, paternal, and cord serum. Placental transfer rates of PFAS differed by compound, and several factors such as gestational age were associated with placental transfer.

The occurrence of PFAS in human placenta and their binding abilities to human serum albumin and organic anion transporter 4

Study Purpose: To better understand the occurrence of PFAS in the placenta and how PFAS might transfer from the placenta.

Study Conclusion: The placental transfer of PFAS is related to the length of the PFAS. More research is needed to understand the occurrence of PFAS in the placenta and the transfer mechanisms of PFAS.

Organophosphate Flame Retardants, Highly Fluorinated Chemicals, and Biomarkers of Placental Development and Disease during Mid-Gestation

Study Purpose: This study measured 12 PFASs and flame retardants in healthy pregnant women in the middle of the pregnancy and examined signs of placental development and disease.

Study Conclusion: This study found potential associations of PFAS and flame retardant exposure with signs related to placenta-related pregnancy complications. Associations with blood pressure and lipid concentrations need further research.

Early life exposure to per- and polyfluoroalkyl substances (PFAS) and latent health outcomes: A review including the placenta as a target tissue and possible driver of peri- and postnatal effects

Study Purpose: To review early life exposure to PFAS and potential latent health outcomes.

Study Conclusion: The effects of PFAS on humans differs based on the compound. Early life PFAS exposure may disrupt placental growth and function, increasing susceptibility for later life chronic conditions, which could worsen from lifelong PFAS exposure.

Perfluoroalkyl Substances (PFAS) and Their Effects on the Placenta, Pregnancy, and Child Development: a Potential Mechanistic Role for Placental Peroxisome Proliferator-Activated Receptors (PPARs)

Study Purpose: To review the current literature on PFAS and their effects on the placenta, pregnancy outcomes, and child health.

Study Conclusion: This review summarizes how PFAS, critical environmental contaminants, may contribute to diseases of pregnancy as well as early and later child health. 

Other

The association between prenatal per-and polyfluoroalkyl substance levels and Kawasaki disease among children of up to 4 years of age: A prospective birth cohort of the Japan Environment and Children’s study

Study Purpose: A systematic review and meta-analysis was conducted by pooling current evidence to investigate the potential association between PFAS exposure and reproductive hormones to promote human reproductive health.

Study Conclusion: Exposure to PFAS was associated with reproductive hormones in the meta-analysis. Researchers found statistically significant results in the association of PFHxS with E2 levels in female, PFOA and PFOS with TT levels in male. Children were more susceptible to PFAS exposure than adults. Even subtle changes in reproductive hormone levels can have serious implications for human health.

Association between exposure to per- and perfluoroalkyl substances (PFAS) and reproductive hormones in human: A systematic review and meta-analysis

Study Purpose: A systematic review and meta-analysis was conducted by pooling current evidence to investigate the potential association between PFAS exposure and reproductive hormones to promote human reproductive health.

Study Conclusion: Exposure to PFAS was associated with reproductive hormones in the meta-analysis. Researchers found statistically significant results in the association of PFHxS with E2 levels in female, PFOA and PFOS with TT levels in male. Children were more susceptible to PFAS exposure than adults. Even subtle changes in reproductive hormone levels can have serious implications for human health.

Exposure to Perfluoroalkyl Substances and Associations with Pubertal Onset and Serum Reproductive Hormones in a Longitudinal Study of Young Girls in Greater Cincinnati(GC) and the San Francisco Bay Area(SFBA)

Study Purpose: The primary objective of this study was to examine the longitudinal relationship between PFAS serum concentrations measured in young girls to determine whether PFAS exposure is associated with the age at three pubertal milestones: thelarche, pubarche, and menarche. To identify subclinical outcomes of the PFAS exposures, we also examined the relationship between serum reproductive hormone concentrations around the time of thelarche with PFAS exposure.

Study Conclusion: PFAS may delay pubertal onset through the intervening effects on BMI and reproductive hormones. The decreases in DHEAS and uppercase e begin subscript 1 end subscriptE1 associated with PFOA represent biological biomarkers of effect consistent with the delay in onset of puberty.

Levels of PFAS concentrations in the placenta and pregnancy complications

Study Purpose: This study aimed to evaluate the potential impacts of PFAS in the placenta.

Study Conclusion: PFOA concentrations in the placenta appeared to be associated with adverse perinatal outcomes, consistent with findings for PFAS concentrations in blood.

Association of exposure to per- and polyfluoroalkyl substances with hemoglobin and hematocrit during pregnancy

Study Purpose: PFAS are common environmental contaminants that have been linked to adverse birth outcomes. However, the association between maternal exposure to PFAS and hemoglobin (Hb) and hematocrit (HCT) remains unclear. The aim of this study was to explore the relationship between PFAS exposure with Hb and HCT during pregnancy.

Study Conclusion: Maternal PFAS exposure was associated with increased serum Hb and HCT. Maternal iron supplementation may affect this relationship.

Association between per- and polyfluoroalkyl substances and semen quality

Study Purpose: Some studies have suggested that PFAS exposure may be associated with semen quality in the general population, but results have not been consistent. To identify a more precise relationship, a meta-analysis was performed.

Study Conclusion: In this study, we discovered that exposure to PFNA and PFOA was negatively associated with sperm progressive motility. Further animal studies should be performed to uncover the causality and elucidate underlying mechanisms. 

Association of serum per- and polyfluoroalkyl substances and gestational anemia during different trimesters in Zhuang ethnic pregnancy women of Guangxi, China

Study Purpose: Gestational anemia is a complication of pregnancy, and a low level of hemoglobin (Hb) has been linked to adverse pregnancy outcomes. Previous studies reported that PFAS were more strongly associated with Hb than red blood cells, indicating that Hb is more susceptible to the effects of PFAS. This study explores the affects of PFAS on anemia in pregnant women.

Study Conclusion: These findings suggest that maternal exposure to PFAS is associated with gestational anemia. Diverse PFAS play roles in increasing and decreasing the risk of gestational anemia in different trimesters. PFDoA was positively associated with gestational anemia in the first trimester, while PFBS was negatively associated with gestational anemia in the second trimester. Further research is needed to understanding these associations.

Maternal Exposure to Per- and Polyfluoroalkyl Substances (PFAS) and Male Reproductive Function in Young Adulthood: Combined Exposure to Seven PFAS

Study Purpose: This study examined associations between maternal plasma PFAS levels during early pregnancy and male offspring reproductive function in adulthood.

Study Conclusion: In a sample of young men, we observed that as maternal PFAS concentrations increased, semen quality in their offspring decreased. 

Associations of per- and polyfluoroalkyl substances (PFAS) and their mixture with oxidative stress biomarkers during pregnancy

Study Purpose: Oxidative stress from excessive reactive oxygen species (ROS) is a hypothesized contributor to preterm birth. PFAS is reported to generate ROS in laboratory settings, and is linked to adverse birth outcomes. However, the relationship between PFAS and oxidative stress has not been examined in the context of human pregnancy. The objective of this study is to investigate the associations between prenatal PFAS exposure and oxidative stress biomarkers in pregnant people.

Study Conclusion: This study is the first to investigate the relationship between PFAS exposure and markers of oxidative stress during pregnancy. They found that PFOS was associated with elevated levels of oxidative stress, which is consistent with findings in animals. Future studies are needed to understand how this may affect fetal development.

Association of maternal perfluoroalkyl substance exposure with postpartum haemorrhage in Guangxi, China

Study Purpose: Postpartum haemorrhage (PPH) is the leading cause of maternal death worldwide, and it may be caused by environmental endocrine disruptors. Prenatal exposure to PFAS has been linked to pregnancy disorders and adverse birth outcomes, but no data are available on the relationship between PFAS exposure during pregnancy and postpartum haemorrhage. This study aimed to explore associations of maternal PFAS exposure with postpartum haemorrhage risk and total blood loss.

Study Conclusion: The concentrations of PFHxS were positively associated with PPH, and the concentrations of PFDoA were negatively correlated with PPH. Exposure to a mixture of nine PFASs was positively correlated with the PPH risk, and PFHxS exposure exerted the most significant effect on the PPH risk. 

Disparities in chemical exposures among pregnant women and neonates by socioeconomic and demographic characteristics: A nontargeted approach

Study Purpose: This study aims to identify sociodemographic differences in exposures that can inform contributions to health inequities.

Study Conclusion: Chemical exposures differed between delivery hospitals likely due to underlying social conditions faced by populations served. Differential exposures to 2,4-dichlorophenol or 2,5-dichlorophenol may contribute to disparities in adverse outcomes.

Longitudinal Changes in Maternal Serum Concentrations of Per- and Polyfluoroalkyl Substances from Pregnancy to Two Years Postpartum

Study Purpose: Exposure to PFAS during pregnancy and lactation is of increasing public health concern, but little is known about longitudinal changes in maternal PFAS concentrations from pregnancy to years postpartum. PFAS were quantified in California mothers during the first, second, and third trimesters of pregnancy and at 3,6, and 24 months after delivery over 2009-2017.

Study Conclusion: From this study, we observed decreases in serum concentrations of n-PFOS, Sm-PFOS, n-PFOA, and PFNA during pregnancy, Sm-PFOS, PFHxS, n-PFOA, and PFNA during early postpartum, and n-PFOS, Sm-PFOS, and PFNA during late postpartum. Throughout the whole study period, later child’s birth year was associated with decreased concentrations of n-PFOS, Sm-PFOS, PFHxS, n-PFOA, and PFNA which appear to reflect regulations and manufacturing changes for these compounds. Longer breastfeeding duration was associated with decreased n-PFOA and PFNA concentrations during late postpartum. Maternal serum PFAS concentration changes from pregnancy to two years postpartum may improve understanding of pregnancy and lactational transfers. Furthermore, our findings might be useful for reconstructing reliable pregnancy or early life PFAS exposure for case-control or cross-sectional epidemiologic studies with only postpartum PFAS serum concentrations.

Association of emerging and legacy per- and polyfluoroalkyl substances with unexplained recurrent spontaneous abortion

Study Purpose: It remains unknown whether exposure to PFAS has any impact on the risk of unexplained recurrent spontaneous abortion (URSA). We conducted a case-control study with 464 URSA cases who had at least 2 unexplained miscarriages and 440 normal controls who had at least one normal livebirth.

Study Conclusion: These findings suggest that exposure to PFAS alternatives may be related to elevated odds of unexplained recurrent spontaneous abortion. More studies are needed to confirm these findings.

Environmental Exposure to 6:2 Polyfluoroalkyl Phosphate Diester and Impaired Testicular Function in Men

Study Purpose: 6:2 diPAP has been demonstrated to disrupt reproductive endocrine functions using experimental studies. However, evidence from humans is not available yet. This study aims to assess the relationship between 6:2 diPAP exposure and the testicular function among adult men.

Study Conclusion: This study suggests that exposure to 6:2 diPAP may inhibit androgen synthesis and impair Leydig cell function in adult men.

Environmental exposure to legacy poly/perfluoroalkyl substances, emerging alternatives and isomers and semen quality in men: A mixture analysis

Study Purpose: This study explores the associations of PFAS with semen quality.

Study Conclusion: In the study, we found that two emerging PFAS replacements (i.e.,6:2 Cl-PFESA and PFBS) and PFHxS exposure were associated with reduced semen concentration, total sperm count and motility in men. Meanwhile, significant positive associations between PFHpS and sperm count and concentration were also observed. But there were no consistent associations between PFAS mixture, branched isomers and semen quality.

Per- and polyfluoroalkyl substances (PFAS) and male reproductive function in young adulthood; a cross-sectional study

Study Purpose: This study aims to examine biomarkers of reproductive function in young adult males according to current environmental exposure to single and combined PFAS.

Study Conclusion: We examined exposure to a range of common PFAS in relation to biomarkers of male reproductive function and found an association with higher levels of FSH (follicle-stimulating hormone) among young men from the general population in Denmark. Further studies on especially combined exposure to PFAS are needed to expand our understanding of potential endocrine disruption from both legacy and emerging compounds in relation to male reproductive function.

Quantitation of linear and branched perfluoroalkane sulfonic acids (PFSAs) in women and infants during pregnancy and lactation

Study Purpose: This paper reviews the literature on the effects of PFAS exposure, with a  specific focus on male reproduction.

Study Conclusion: Increasing awareness of the potential health implications of PFAS and realization of the extent of environmental contamination has led to a rising demand for research into definitive health risks and effective remediation strategies. Animal models have been widely employed to investigate in vitro and in vivo consequences of PFAS exposure, as well as the toxicology of these chemicals. Such studies complement a growing body of evidence from human epidemiological studies. However, the literature abounds with conflicting evidence, and as such, it remains challenging to draw accurate conclusions regarding the causality of PFAS related health issues. This situation is exacerbated by the repeated demonstration that outcomes differ depending on factors such as the specific PFAS chemical(s) (of which there are over 4,700), stage of development (i.e., during fetal development or in later life) and duration of exposure, level and mix of contamination, route of exposure, and interaction with other environmental contaminants and toxicants, all of which are influenced by geographical location. These factors present significant difficulties for researchers in planning, executing, and interpreting studies, and thus hinder our ability to directly compare PFAS exposure studies. While standardization therefore remains an essential priority for future research, the identification of appropriate cellular model(s) with which to directly investigate and unlock the interaction of PFAS with the male reproductive system would also be advantageous. In addition, agreement is needed regarding endpoint measures, in which subtle changes, such as decreases in fertility or metabolic sequelae, may be used as early markers of PFAS-mediated health effects, rather than more extreme factors such as tumors. In this regard, the male reproductive system offers notable advantages as a sensitive marker of human disease and may ultimately provide a unique opportunity for assessing the emerging threat to human health posed by PFAS exposure. Indeed, this model draws on a growing body of evidence of a strong association between a male’s general health and reproductive potential, with infertility being strongly correlated with future health concerns such as testicular cancer, ischemic heart disease and diabetes.

 

A Review of Per- and Polyfluorinated Alkyl Substance Impairment of Reproduction

Study Purpose: In this article, they review studies describing PFAS exposure and reproductive effects in animals and humans. The aim was to compare environmental occurrence and effects of the most prominent long-chain PFAS compounds and their short-chain replacements.

Study Conclusion: The chemical properties of PFAS are valuable for manufacturing and consumer convenience; however, these same properties make them resistant to degradation and persistent in the environment, wildlife, and humans. Generally, longer carbon chains in PFAS correlate with higher toxicity, however, differential reproductive effects are observed in vitro and in vivo. Short-chain PFAS tend to bioaccumulate less, but are more persistent in surface water. While surface water data show individual short-chain PFAS presence to be in the low ng/L range, sum total concentrations of PFAS are orders of magnitude higher. Some studies indicate that reproductive effects of PFAS seen in laboratory models and human cell lines are at concentrations greater than what will be realized in the environment. Most studies do not consider mixture toxicity; epidemiological studies inherently address mixture toxicity. Epidemiological studies indicate that environmentally-relevant PFAS concentrations are associated with reproductive effects. Indeed, even though most ecological and epidemiological studies quantify a few PFAS, these studies are effectively assessing the impact of many more PFAS. The majority of evidence for reproductive effects is linked to long-chain PFAS exposure. Long-chain PFAS is on the decline worldwide but will remain an exposure issue. Short-chain PFAS exposure is on the rise. Even though some specific short-chain PFAS have been studied, data on reproductive effects of short-chain PFAS are considerably less than for long-chain. In addition, there are many short-chain PFAS byproducts from manufacturing that have yet to be identified.

Quantitation of linear and branched perfluoroalkane sulfonic acids (PFSAs) in women and infants during pregnancy and lactation

Study Purpose: PFAS are associated with negative health effects and exposure during fetal life and infancy are of concern. The objective of this study was to investigate types of PFAS in never-pregnant, pregnant, and postpartum women and infants. 

Study Conclusion: The linear relations between PFSA concentrations in infants aged six months and mothers in pregnancy week 18 confirm that pregnancy and lactation are major excretion routes for PFSA, but accumulate in the infant. The observed great variability in PFSA burden among mothers and infants, as well as the reduced maternal transfer of branched PFHxS isoforms and increased transfer of branched PFOS isoforms compared to the respective linear isoforms to the infant, might impact adverse health effects associated with PFSA exposure, but this should be confirmed in future studies.

Overview of the Mechanisms of Action of Selected Bisphenols and Perfluoroalkyl Chemicals on the Male Reproductive Axes

Study Purpose: This study provides an overview of mechanisms of action common to PFAS and bisphenols on male fertility.

Study Conclusion: The negative impact of endocrine disrupting chemicals (EDCs) (such as PFAS) on fertility has been demonstrated. However, there are differences between laboratory experiments and human studies. We are exposed to many different EDCs and not all mixtures can be evaluated. The results of this review provided indication that persistent and non-persistent EDCs are associated with formation of ROS, disruption of BTB, disturbance of testosterone production, and interference with estrogenic and antiandrogenic signaling at environmentally relevant concentrations.

Mixtures of persistent organic pollutants are found in vital organs of late gestation human fetuses

Study Purpose: This study measured persistent organic pollutants, such as PFAS, in maternal serum, placenta, and fetal tissues in 20 pregnancies that ended in stillbirth.

Study Conclusion: This study quantified many POPs in fetal tissues. All studied chemical projects were detected in fetal adipose tissue even in places when the chemical was not detected in the maternal serum and placenta.

A case-cohort study of perinatal exposure to potential endocrine disrupters and the risk of cryptorchidism in the Norwegian HUMIS study

Study Purpose: Exposure to PFAS and other endocrine-disrupting chemicals (EDCs) during the critical period of testicular descent may increase the risk of cryptorchidism and male fertility. The objective of this study was to investigate 27 potential EDCs in breast milk and the risk of cryptorchidism.

Study Conclusion: Perinatal exposure to PCB-74, PCB-114, PCB-194, and B-HCH were associated with increased odds of congenital cryptorchidism.

Exposure to endocrine disrupting chemicals (EDCs) and cardiometabolic indices during pregnancy: The HOME Study

Study Purpose: Toxicology studies have identified pregnancy as a time sensitive to endocrine disrupting chemicals (EDCs), such as PFAS, and cardiometabolic indices in women. No study has examined this in humans.

Study Conclusion: Overall, there were positive associations between PBDEs with glucose and cholesterol levels during pregnancy, while negative associations were found between some phthalates and cholesterol. No relationship was noted for BPA or PFAS with cardiometabolic indices during pregnancy across both models.

Associations of single and multiple per- and polyfluoroalkyl substance (PFAS) exposure with vitamin D biomarkers in African American women during pregnancy

Study Purpose: Vitamin D has been linked to various physiological function in pregnant women and their fetuses. This study aims to evaluate the associations of PFAs levels with vitamin D levels during pregnancy in a cohort of African American women in Atlanta.

Study Conclusion: This study suggests that exposure to PFAs might disturb vitamin D metabolism among pregnant African American women and that some of these effects might be changed by the sex of the fetus. More studies are needed to confirm these findings.

Association between maternal exposure to perfluoroalkyl and polyfluoroalkyl substances and risks of adverse pregnancy outcomes: A systematic review and meta-analysis

Study Purpose: This reviews and analyzes previous studies on the relationship of maternal PFAS exposure and adverse pregnancy outcomes.

Study Conclusion: It was found that maternal exposure to PFOS could be positively associated with preterm birth, while no statistically significant association have been found between PFASs exposure and miscarriage and stillbirth. Epidemiological evidence to date are insufficient to draw definitive conclusions on potential toxicities of PFASs with stronger statistical power.

Associations of single and multiple per- and polyfluoroalkyl substance (PFAS) exposure with vitamin D biomarkers in African American women during pregnancy

Study Purpose: Vitamin D has been linked to various physiological function in pregnant women and their fetuses. This study aims to evaluate the associations of PFAs levels with vitamin D levels during pregnancy in a cohort of African American women in Atlanta.

Study Conclusion: This study suggests that exposure to PFAs might disturb vitamin D metabolism among pregnant African American women and that some of these effects might be changed by the sex of the fetus. More studies are needed to confirm these findings.

Maternal exposure to perfluoroalkyl chemicals and anogenital distance in the offspring: a Faroese cohort study

Study Purpose: Exposure to PFASs has in some studies been associated with reduced anogenital distance in newborns, an indicator of prenatal anti-androgenic exposure. The aim of this study was to investigate the association between maternal PFAS exposure and offspring anogenital distance in a population with wide ranges of PFAS exposures.

Study Conclusion: In conclusion, we found that maternal PFAS exposure was significantly associated with a longer AGDs in boys. No significant associations were found among girls, suggesting sex-dimorphic effects of PFASs. Whether the observed association with longer ASD and PFAS influences the reproductive health of males is unknown and needs to be investigated further.

Prenatal exposures to mixtures of endocrine disrupting chemicals and children's weight trajectory up to age 5.5 in the SELMA study

Study Purpose: This study evaluates the effect of prenatal exposure to mixtures of endocrine disrupting chemical (such as PFASs) mixtures on birthweight and childhood weight trajectories.

Study Conclusion: Prenatal exposure to EDC mixtures was associated with lower birthweight and altered infant weight gain trajectories.

Exposure to perfluoroalkyl substances in early pregnancy and risk of sporadic first trimester miscarriage

Study Purpose: The aim of this study was to investigate whether PFASs in early pregnancy are associated with unexplained, sporadic first trimester miscarriage.

Study Conclusion: There was an association between PFOA and miscarriage in this study. The study can only represent early placentation and clinical pregnancy loss during the second half of the first trimester.

Perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) and DNA methylation in newborn dried blood spots in the Upstate KIDS cohort

Study Purpose: PFOA and PFOS may alter prenatal development, through modifying DNA. Prior studies on this subject have had few subjects and inconsistent results. This study examines relationships between PFOA and PFOS with DNA changes among nearly 600 infants.

Study Conclusion: There was limited evidence of an association between high concentrations of PFOA/PFOS and DNA changes in newborns in this study. Future studies are needed in populations with higher concentrations of PFOA/PFOS.

Prenatal Exposure to Per- and Polyfluoroalkyl Substances, Umbilical Cord Blood DNA Methylation, and Cardio-Metabolic Indicators in Newborns: The Healthy Start Study

Study Purpose: This study looks at the associations between prenatal PFAS exposure and changes in DNA in umbilical cord blood.

Study Conclusion: DNA changes in umbilical cord blood were associated with maternal PFAS concentrations during pregnancy, which could affect offspring growth, metabolism, and immune function.

Per- and polyfluoroalkyl substance mixtures and gestational weight gain among mothers in the Health Outcomes and Measures of the Environment study

Study Purpose: This study looks at associations between PFAS exposure and gestational weight gain.

Study Conclusion: Although there were consistent small increases in gestational weight gain with increasing PFOA, PFOS, and PFNA serum concentrations in this cohort, the associations were imprecise. Additional investigation of the association of PFAS with GWG in other cohorts would be informative and could consider pre-pregnancy BMI as a potential modifier.

Perfluoroalkyl substances exposure in early pregnancy and preterm birth in singleton pregnancies: a prospective cohort study

Study Purpose: To investigate the associations between prenatal PFAS exposure and preterm birth among singleton live births.

 

Breastfeeding

Breastfeeding covers PFAS and levels in human milk, breastfeeding duration, levels in dairy milk and formula, and trends over time. This section currently 52 total papers; 40 from the last 6 years. Although a study may find, or not find, an association between PFASs and breastfeeding outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Breastfeeding

Maternal serum per- and polyfluoroalkyl substances during pregnancy and breastfeeding duration

Study Purpose: This study looks at associations between maternal PFAS levels during pregnancy and breastfeeding duration.

Study Conclusion: Among women with one child, there was not evidence for associations between PFAS levels and breastfeeding duration. However, in women with multiple children, PFAS levels were associated with reduced breastfeeding duration.

Plasma concentrations of per- and polyfluoroalkyl substances in pregnancy and breastfeeding duration in Project Viva

Study Purpose: PFAS may disrupt mammary gland development and function, reducing milk supply and breastfeeding duration. However, this has not been well studied in humans.

Study Conclusion: These findings suggest that exposure to PFAS may be associated with reduced breastfeeding duration.

Public Health Evaluation of PFAS Exposures and Breastfeeding: A Systematic Literature Review

Study Purpose: This review explores whether exposure to PFAS through breastfeeding is associated with adverse health outcomes among infants and children using evidence from animal and human studies.

Study Conclusion: This review explores the evidence of adverse health effects as a result of PFAS exposure through breastfeeding. A limited number of animal studies suggest a relationship between feeding from a mother exposed to PFOA and body weight gain, relative liver weight, and impairment of mammary gland development. The evidence of health effects from lactational exposure to PFOS and other PFAS is too limited to form a conclusion. This is a large research gap and inferences about the health consequences of exposure through breastfeeding cannot be made.

Per- and Polyfluoroalkyl Substances and Breastfeeding as a Vulnerable Function: A Systematic Review of Epidemiological Studies

Study Purpose: Breastmilk formation is a hormonally-regulated process that may be sensitive to the effects of certain chemical exposures. PFAS exposure has been associated with insufficient mammary gland development in mice and reduced breastfeeding duration in humans. The aim of this review was to assess the epidemiological evidence on the association between PFAS exposure and breastfeeding duration.

Study Conclusion: This review suggests that breastfeeding may be sensitive to PFAS exposure. Thus, in addition to direct negative effects of PFAS on child health, maternal PFAS exposure may also indirectly negatively impact child health through reduced breastfeeding. Given that other factors also affect women's ability to breastfeed, more research is needed to better understand which exposure might impair breastfeeding and to better understand the mechanisms behind these effects.

Emerging and Legacy Perfluoroalkyl Substances in Breastfed Chinese Infants: Renal Clearance, Body Burden, and Implications

Study Purpose: Human breast milk is a primary route of exposure to PFAS in infants. To understand the associated risks, the occurrence of PFAS in human milk and how PFAS are stored and move in the body of infants needs to be addressed. This study determines levels of PFS in human milk and urine samples from breastfed infants, estimated clearance from the kidneys, and predicted infant PFAS levels in the blood.

Study Conclusion: These results demonstrate the widespread occurrence of emerging PFAS in human milk in China. This suggests potential health risks of postnatal exposure in newborns.

Changes in perfluoroalkyl substances (PFAS) concentrations in human milk over the course of lactation: A study in Ronneby mother-child cohort

Study Purpose: Little is understood about how PFAS concentrations in breast milk change over the course of lactation, although this is an important determinant of total infant exposure to PFAS through breastfeeding. This study estimates changes in PFAS concentrations in breast milk over the course of lactation in a population with a wide range of exposure from background-to high-exposed.

Study Conclusion: This study estimated changes in PFAS concentration between paired colostrum and milk samples from mothers with a wide range of PFAS exposures, including women who had been highly exposed to PFAS from AFFF-contaminated drinking water. The estimated changes varied by PFAS and by initial maternal colostrum concentration, suggesting a possible effect of maternal exposure level. These results illustrate the importance of studying PFAS exposures in highly exposed populations. The cumulative breastfeeding exposures in children of highly exposed mothers will depend both on the specific mixture of PFAS contamination as well as the nature of the exposure source (i.e., ongoing or stopped).

Per- and polyfluoroalkyl substances (PFAS) in breast milk and infant formula: A global issue

Study Purpose: PFAS are transferred from mothers to infants through breastfeeding. Infants can also be exposed to PFAS through infant formula consumption. A recent literature-based scoping of breast milk levels reported that four PFAS often exceeded the United States Agency for Toxic Substances and Disease Registry (ATSDR) children's drinking water screening levels in both the general population and highly impacted communities in the U.S. and Canada. This work presents a comparison of global breast milk and infant formula PFAS measurements with the only reported health-based drinking water screening values specific to children.

Study Conclusion: The results from our earlier paper on measured and modeled levels of PFAS in breast milk in the US and Canada – and confirmed by more recent Canadian data  – indicate that breast milk PFAS levels often exceed children's drinking water screening values and that this issue warrants immediate attention. The results from this current effort make it clear that this issue is a global one. The available data suggest that it is not uncommon for PFOS and PFOA breast milk levels from around the world to exceed the respective children's drinking water screening values.

Assessment of organohalogenated pollutants in breast milk from the Czech Republic

Study Purpose: This biomonitoring effort brings new information on the occurrence of 94 organohalogenated pollutants in 231 human breast milk samples collected in 2019 and 2021 from women in two regions of the Czech Republic. This study aimed to evaluate the concentrations of six PCBs, 10 OCPs, 34 HFRs, 29 PFAS, and 15 PCNs.

Study Conclusion: Concentrations of PFAS were low, and only some chemicals in this group were quantified in the breast milk samples. In the last decade, a decrease in PFAS concentrations in breast milk has been documented in the Czech Republic.

Levels of persistent organic pollutants in breast milk samples representing Finnish and Danish boys with and without hypospadias

Study Purpose: Hypospadias is a congenital malformation of penile urethra with unknown origins. Persistent organic pollutant (POP) exposure may disrupt endocrine function during a critical window of development in male genitalia. In animals studies, POPs have been associated with male reproductive disorders, including hypospadias, but few studies have assessed this relationship in humans. This study investigates the association between hypospadias and POP concentrations in breast milk, as a proxy measure for prenatal exposure. 

Study Conclusion: This study did not find evidence of an association between hypospadias and prenatal exposure to POPs such as PFAS through breast milk. Future studies are needed to confirm these findings.

Occurrences of legacy and emerging per- and polyfluoroalkyl substances in human milk in China: Results of the third National Human Milk Survey (2017-2020)

Study Purpose: PFAS are persistent organic pollutants widely contaminated and exposed in humans. China is a major manufacturer and consumer of these chemicals. To characterize the occurrences, geographical variations, temporal trends, and exposure risks of PFAS in women and their children in China, 30 PFAS were measured in human milk samples from 100 sites in 24 provinces.

Study Conclusion: This study from samples in China showed that L-PFOA was the predominant PFAS in milk, followed by L-PFOS and 6:2 Cl-PFESA. The highest PFOA exposure was observed in Shandong province, and the geographic variance of PFOA was different from PFOS and 6:2 Cl-PFESA.

Time-course trend and influencing factors for per- and polyfluoroalkyl substances in the breast milk of Korean mothers

Study Purpose: Many studies have reported that neonates and infants are exposed to several PFAS via breastfeeding; however, these studies have had small sample sizes. This study aimed to determine the concentrations and time-course trend of PFAS in breast milk and identify factors influencing PFAS concentrations in breastmilk.

Study Conclusion: The purpose of this study was to confirm the concentrations of 14 PFAS in 207 breast milk samples and determine the association between PFAS concentration in breast milk and diet and consumer products in Korea. The concentration of PFOS was found to be associated with frequent fish intake. Overall, the concentration of PFASs in breast milk in Korea was higher than that reported in other countries. Compared to the concentration of PFOA in breast milk 12 years ago, the current concentration of PFOA in breast milk increased by approximately three times (278%). 

Breastfed infants' exposure to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins and dibenzofurans, and per- and polyfluoroalkyl substances: A cross-sectional study of a municipal waste incinerator in China

Study Purpose: This is a study of breastfeeding mothers living near a municipal waste incinerator in China. This study evaluates the concentrations of PCBs, PCDD/Fs, and PFAS in breast milk and their infants' estimated daily intake.

Study Conclusion: The study showed that compared to 2013, the concentrations of PCDD/Fs and PCBs in the mothers' breast milk decreased, and the infants' estimated daily intake declined. The potential health risks posed by legacy PCDD/F and PCB pollutants were not particularly high, but emerging PFAS pollutants were a new cause for concern.

Mixture of environmental pollutants in breast milk from a Spanish cohort of nursing mothers

Study Purpose: In this study, the levels of a wide range of pollutants were measured in breast milk of Spanish nursing mothers.

Study Conclusion: The occurrence of DDT, DDE, HCB, Oxy-CD, PCBs, PBDEs, PFASs, chlorpyrifos, BPA, TBBPA, as well as other toxic and essential elements was determined in 60 breast milk samples. Maternal characteristics, such as age and BMI, seem to be linked to higher levels of POPs (DDT, DDE and PCBs). Higher concentrations of PCBs were detected in Spanish and primiparous mothers. Breast milk of low-income mothers had higher DDT and DDE levels than high-income mothers, evidencing the influence of the socio-economic status on the women’s exposure to environmental pollutants. 

Poly- and perfluoroalkyl substances (PFAS) exposure through infant feeding in early life

Study Purpose: This study investigates PFOA and PFOS levels in human milk over time and the daily PFAS intake through infant feeding in the first 3 months of life, the most important determinants and the correlation with PFAS plasma levels at age 3 months and 2 years.

Study Conclusion: Human milk contains PFOA and PFOS, in contrast to formula feeding. Daily PFOA and PFOS in early life is highest in exclusively breastfed infants and it is highly correlated with infant's plasma levels throughout infancy. These findings show that breastfeeding is an important PFAS exposure pathway in the first months of life, with unknown but potential adverse effects.

Current Breast Milk PFAS Levels in the United States and Canada: After All This Time, Why Don't We Know More?

Study Purpose: The objectives of this study are to 1. document published breast milk concentrations in North America 2. estimate breast milk PFAS levels from maternal serum concentration in national surveys and communities impacted by PFAS 3. compare measured/estimated milk PFAS concentrations to screening values.

Study Conclusion: This paper used three studies reporting breast milk concentrations in the United States and Canada. Measured and estimated breast milk concentrations were compared to children's drinking water screening values. Breast milk concentrations varies widely between different communities. All estimated breast milk PFOA and PFOS concentrations exceeded drinking water screening values for children. Exceeding a children’s drinking water screening value does not indicate that adverse health effects will occur and should not be interpreted as a reason to not breastfeed; it indicates that the situation should be further evaluated. It is past time to have a better understanding of environmental chemical transfer to—and concentrations in—an exceptional source of infant nutrition.

Polychlorinated dioxins and dibenzofurans (PCDD/F), polybrominated dioxins and dibenzofurans (PBDD/F), polychlorinated biphenyls (PCB), polybrominated diphenyl ethers (PBDE), and per- and polyfluoroalkyl substances (PFAS) in German breast milk samples (LUPE 8)

Study Purpose: This study quantified PBDEs, PFAS, and ADONA in breast milk samples collected in two German states and breast milk and blood samples from subjects additionally exposed to PFOA.

Study Conclusion: For PCDD/F, PBDD/F, dl-PCB, PBDE, and ndl-PCB, our results are in line with other recently published studies in Europe. In contrast to previous studies from Germany lower concentrations of these compounds were found in breast milk samples. The concentrations of PFAS are low and only PFOA and PFOS could be quantified in some samples. For all target analytes a declining time trend could be observed. Nevertheless, this study shows that the population is still exposed to various persistent organic pollutants and that a further reduction in exposure to these compounds is necessary to prevent health risks.

Prenatal and postnatal exposure to emerging and legacy per-/polyfluoroalkyl substances: Levels and transfer in maternal serum, cord serum, and breast milk

Study Purpose: Gestation and lactation are vulnerable stages for fetuses and newborns. During these periods, PFASs accumulated in mothers can be transferred to newborns through placenta and/or breastfeeding, causing potential health risks. To investigate the pre- and postnatal PFAS exposure of newborns, this study analyzed 21 emerging and legacy PFASs in 60 sets of maternal serum samples and breast milk samples.

Study Conclusion: The one month postnatal exposure to PFASs via breastfeeding was much higher than prenatal exposure in utero. This study enhances the understanding of transplacental and breastfeeding transfer of PFASs and provides assessments of prenatal and postnatal exposure of newborns to emerging and legacy PFASs.

Breastfeeding initiation and duration after high exposure to perfluoroalkyl substances through contaminated drinking water: A cohort study from Ronneby, Sweden

Study Purpose: This study investigates associations between high PFAS exposure and 1. initiation and 2. duration of breastfeeding.

Study Conclusion: Exposure to high levels of PFAS seemed to be associated with increased risks of not initiating breastfeeding duration in primiparous mothers. The findings imply that the ability of first-time mothers to establish breastfeeding is a sensitive outcome after high exposure to PFAS.

Occurrence and infant exposure assessment of per and polyfluoroalkyl substances in breast milk from South Africa

Study Purpose: This study investigates the occurrence of PFAS in breast milk of nursing mothers from South Africa.

Study Conclusion: This study provides background data on the occurrence and infant exposure assessment of PFAS in exclusively breastfed infants. The results that PFAS with short and long carbon chains were more prevalent and occurred at higher concentrations in breast milk. The study found that the concentrations of PFAS did not influence infant birth weight and gestational period, however, infant sex and frequency of milk consumption showed strong relationships with PFAS levels in breast milk. Further analysis showed that on average, breastfed infants are at risk to PFOA but not PFOS.

Exposure to per- and polyfluoroalkyl substances associates with an altered lipid composition of breast milk

Study Purpose: This study sought to define the impact of maternal exposure to PFAS on lipid composition of human breast milk and to study the combined impact of maternal PFAS exposure and breast milk lipid composition on the growth of infants.

Study Conclusion: This data suggests that maternal exposure to PFAS impacts the nutritional quality of the breast milk, which, in turn, could impact children.

Concentrations of perfluoroalkyl substances in donor breast milk in Southern Spain and their potential determinants

Study Purpose: This study assesses the concentrations of PFAS in breast milk from donors to a human milk bank and explore factors potentially related to this exposure.

Study Conclusion: Several PFAS, including short-chain compounds, are detected in pooled donor milk samples. Breast milk may be an important pathway for the PFAS exposure of breastfed infants, including preterm infants in NICUs. Despite the reduced sample size, these data suggest that various lifestyle factors influence PFAS concentrations, highlighting the use of PCPs.

Per- and Polyfluoroalkyl Substances (PFAS) in Breast Milk: Concerning Trends for Current-Use PFAS

Study Purpose: This study reviewed current levels of various PFAS in U.S. mothers' breastmilk.

Study Conclusion: Our results indicate that while the legacy PFOS and PFOA are still the most abundant PFAS in breast milk, similar to the studies from the early 2000s, the detection frequencies and concentrations of several current-use short chain PFAS have significantly increased since then.

Exposure to perfluoroalkyl substances through human milk in preterm infants

Study Purpose: This study aimed to quantify the potential exposure of preterm infants to PFASs through breast milk.

Study Conclusion: The exposure of preterm infants to PFASs through breast feeding might exceed values reported for older, healthier infants.

Regional occurrence of perfluoroalkane substances in human milk for the global monitoring plan under the Stockholm Convention on Persistent Organic Pollutants during 2016-2019

Study Purpose: The human milk monitoring component of the global monitoring plan under the Stockholm Convention on Persistent Organic Pollutants was implemented from 2016-2019 and had 44 human milk samples from 42 countries collected and analyzed for PFASs.

Study Conclusion: Statistical analysis showed that PFOS and PFOA levels in breast milk were significantly different between European countries and African and Latin American countries, as well as between high-income and low-income countries. PFOA tended to have higher concentrations in wealthier countries. No correlation was found for population density.

Endocrine-disrupting chemicals and breastfeeding duration: a review

Study Purpose: This study describes current literature investigating how chemicals such as PFAS affect mammary gland development and function, thereby impacting lactation duration.

Study Conclusion: Certain chemicals may play a role in mammary gland development, function, and lactation, which can affect breastfeeding duration. PFSAs may reduce breastfeeding duration through impaired mammary gland development.

Determination and assessment of human dietary intake of per and polyfluoroalkyl substances in retail dairy milk and infant formula from South Africa

Study Purpose: This study measured PFAS levels in dairy milk and infant formula to start quantifying how much exposure people receive through these products.

Study Conclusion: This study presents the first data on the occurrence and human dietary intake of PFAS in dairy milk and infant formulas on the African continent. The data showed that long chain perfluorocarboxylic acids are
ubiquitous in South African dairy milk and infant formula. Compared to long chain (C9 – C14) PFAS, the concentrations of PFOA and PFOS were generally low.

Biomonitoring of PFOA, PFOS and PFNA in human milk from Czech Republic, time trends and estimation of infant's daily intake
Study Purpose: This is a longitudinal observation of three PFAS in human breast milk. It provides helpful information about these levels over time.
Study Conclusion: Significant time-related decreasing trends in the PFOS and PFOA levels in human milk were observed. Nevertheless, the body burden of infants from breastfeeding might pose an enhanced health risk to infants when the current PTWI values are applied. These findings strongly support the present EU efforts to phase out PFOA, it's salts and PFOA related compounds. Since PFOS exposure there has still been widely detected despite PFOS usage reduction measures, the major exposure routes should be further monitored and, if possible, eliminated.

Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China

Study Purpose: To determine the level of PFAS in breast milk.

Study Conclusion: China saw higher levels of PFASs in breast milk samples than Swedish samples.

Early Life Exposure to Perfluoroalkyl Substances (PFAS) and ADHD: A Meta-Analysis of Nine European Population-Based Studies

Study Purpose: To see if infants exposed to PFOS or PFOA have a higher rate (prevalence) of ADHD diagnosis.

Study Conclusion: The study did not observe a significant increase in the prevalence of ADHD diagnosis in association with early life exposure to PFOS and PFOA, in a sample of almost 5,000 children from nine European population based studies.

Concentrations of perfluoroalkyl substances in human milk from Ireland: Implications for adult and nursing infant exposure

Study Purpose: This study attempted to better quantify PFAS levels in breast milk.

Study Conclusion: Concentrations in human milk in Ireland fall within the range of those reported previously for other countries, and exposure to PFASs of Irish nursing infants via consumption of human milk does not appear to constitute a health concern.

A transgenerational toxicokinetic model and its use in derivation of Minnesota PFOA water guidance

Study Purpose: This study attempts to create a model to guide water recommendations.

Study Conclusion: This study observed breastfed infant serum levels at 4.4-fold higher than in formula-fed infants, with both of these scenarios producing serum levels in excess of the adult steady-state level.

Poly- and perfluoroalkyl substance concentrations in human breast milk and their associations with postnatal infant growth

Study Purpose: This study examined the concentrations of PFASs in breast milk from 174 women and investigated the association between lactation exposure to these PFASs through breast milk consumption and the postnatal growth of infants.

Study Conclusion: This study demonstrated that lactation exposure to C8-C10 PFCAs, 8:2 FTOH, and 6:2 Cl-PFESA through breast milk consumption may affect postnatal infant growth.

Per- and polyfluoroalkyl substances in human breast milk and current analytical methods

Study Purpose: To review current information on PFAS in human breast milk, including the challenges of analysis and the possible modes of transfer from maternal blood.

Study Conclusion: Data suggests a global decline in PFAS levels in breast milk.

The serum concentrations of perfluoroalkyl compounds were inversely associated with growth parameters in 2-year old children

Study Purpose: This study investigates the relationship between the serum levels of PFASs and growth in 2-year-old children.

Study Conclusion: In conclusion, the serum concentrations of PFCs were inversely associated with growth parameters in 2-year-old children.

Perfluoroalkyl Acids (PFAAs) in Serum from 2-4-Month-Old Infants: Influence of Maternal Serum Concentration, Gestational Age, Breast-Feeding, and Contaminated Drinking Water

Study Purpose: This study investigates associations between PFAS levels in 2-4 month-old infants and factors that may contribute to these levels.

Study Conclusion: PFOA, PFNA, and PFHxS infant levels increased with exclusive breastfeeding in this study. Infants living in areas with PFAS-contaminated drinking water had higher PFBS and PFHxS levels. Prenatal and postnatal PFAS exposure appear to contribute to infant PFAS levels.

Perfluoroalkyl substances (PFASs) in breast milk from Korea: Time-course trends, influencing factors, and infant exposure

Study Purpose: In this study, PFASs were analyzed in breast milk samples collected during various lactation periods to determine maternal exposure levels, variations over time, and infant health risks.

Study Conclusion: PFOS, PFOA, PFUnDA, and PFNA were the predominant compounds found in these breast milk samples. The concentrations of PFASs in breast milk were correlated with maternal age, BMI, and the mother's number of children. Dietary behaviors, such as snack and milk consumption and the frequency of eating out, were associated with increased levels of PFASs. The daily intakes of PFOS and PFOA for infants through breast milk consumption were lower than the recommended threshold.

Perfluoroalkyl substances in Breast milk, infant formula and baby food from Valencian Community (Spain)

Study Purpose: This study reports levels of PFASs in breast milk, infant formulas, and baby food from a Spanish community in order to evaluate the infant exposure to these substances through the diet.

Study Conclusion: This study found PFBA in 100% of the samples of breast milk and other baby foods. The dietary intake of PFOS and PFOA varies significantly depending on the infant diet.

Exposure of Norwegian toddlers to perfluoroalkyl substances (PFAS): The association with breastfeeding and maternal PFAS concentrations

Study Purpose: To examine the PFAS blood levels in toddlers and to determine their relationship with maternal PFAS concentrations in pregnancy and breastfeeding duration.

Study Conclusion: These results suggests that transplacental transfer and breastfeeding are among the main determinants of PFOS, PFOA, PFHxS, and PFHpS levels in toddlers, while that was not the case for PFNA and PFUnDA.

Shorter duration of breastfeeding at elevated exposures to perfluoroalkyl substances

Study Purpose: To determine whether maternal exposure to PFASs affects the ability to breastfeed.

Study Conclusion: Increased maternal levels of PFAS are associated with a decreased duration of breastfeeding in this study.

Maternal serum perfluoroalkyl substances during pregnancy and duration of breastfeeding

Study Purpose: This study looks at the association between maternal PFAS exposure and breastfeeding duration.

Study Conclusion: Higher PFOA concentrations in mothers were related to shorter breastfeeding duration in this study.

Elevated levels of short carbon-chain PFCAs in breast milk among Korean women: Current status and potential challenges

Study Purpose: In this study, breast milks were sampled from lactating women and measured for PFASs.

Study Conclusion: Several short chain PFASs were detected at high levels. Their levels of detection were often comparable to levels of PFOS. For PFHpA, the use of cosmetics and non-stick frying pans were identified as significant sources of exposure among lactating women.

 

Nervous System and Behavior

Neurodevelopment covers mainly outcomes in children, including cognitive abilities, cognitive development, ADHD, neurologic disease, autism, IQ, reading skills, and behavior. This section currently has 53 total studies: 52 from the last 6 years. Although a study may find, or not find, an association between PFASs and neurodevelopmental outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

ADHD

Association between early-childhood exposure to perfluoroalkyl substances and ADHD symptoms: A prospective cohort study

Study Purpose: This study explores associations between early-childhood exposure to PFAS and ADHD symptoms later in childhood. 

Study Conclusion: Exposure to PFAS at the age of 2 years was associated with increased ADHD symptoms in school-aged children at the age of 8 years. Many PFAS exhibited showed more complex relationship with ADHD symptoms; these associations were stronger at lower PFAS levels.

The association between prenatal perfluoroalkyl substance exposure and symptoms of attention-deficit/hyperactivity disorder in 8-year-old children and the mediating role of thyroid hormones in the Hokkaido study

Study Purpose: To investigate the impact of maternal PFAS exposure on children's ADHD symptoms, and how this association may vary with thyroid hormone levels.

Study Conclusion: Higher PFAS levels in maternal serum during pregnancy were associated with lower risks of ADHD symptoms at 8 years old. The association was stronger among first-born children in relation to hyperactivity-impulsivity than with regard to inattention. There was little modification by thyroid hormone levels during pregnancy in the association between maternal exposure to PFAS and reduced ADHD symptoms at 8 years old.

No association between maternal and child PFAS concentrations and repeated measures of ADHD symptoms at age 2½ and 5 years in children from the Odense Child Cohort

Study Purpose: The potential impact of exposure to PFAS on childhood ADHD is unclear. The majority of previously conducted studies found no association between maternal PFAS concentrations and ADHD symptoms in offspring, but some studies have observed possible associations with postnatal PFAS exposures, mainly in girls. This study investigates the association between maternal and child serum concentrations of five PFAS and symptoms of ADHD at ages 2.5 years and 5 years.

Study Conclusion: This study did not find evidence of an association between early-life PFAS exposure and the risk of developing systems of ADHD.

The association between maternal perfluoroalkyl substances exposure and early attention deficit hyperactivity disorder in children: a systematic review and meta-analysis

Study Purpose: This review verifies the association between maternal PFAS exposure and ADHD by reviewing existing studies.

Study Conclusion: This study showed that maternal exposure to PFASs was not associated with the prevalence rate of ADHD in children. Researchers observed that exposure type and regional factor may influence the occurrence of ADHD. More epidemiological studies should be encouraged, especially on the exposure type of PFASs, to understand the pathogenesis of ADHD in more depth. Further research should be carried out widely in different regions.

Early Life Exposure to Perfluoroalkyl Substances (PFAS) and ADHD: A Meta-Analysis of Nine European Population-Based Studies

Study Purpose: This study investigates the association between early life exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), and ADHD in a collaborative study including nine European population-based studies, encompassing 4,826 mother–child pairs.

Study Conclusion: There may be increased prevalence of ADHD in association with PFAS exposure in girls, in children from women who have had multiple children, and in children from low-educated mothers.

Prenatal exposure to perfluoroalkyl substances and associations with symptoms of attention-deficit/hyperactivity disorder and cognitive functions in preschool children

Study Purpose: This study looks at the associations between prenatal exposure to PFASs and symptoms of ADHD and cognitive functioning (language skills, estimated IQ, and working memory) in preschool children, and whether this association varies by sex.

Study Conclusion: The study did not find consistent evidence to conclude that prenatal exposure to PFASs are associated with ADHD symptoms or cognitive dysfunctions in preschool children aged three and a half years. The results showed some associations between PFASs and working memory, particularly negative relationships with nonverbal working memory, but also positive relationships with verbal working memory. The relationships were weak, as well as both positive and negative, which suggest no clear association.

Early-life exposure to persistent organic pollutants (OCPs, PBDEs, PCBs, PFASs) and attention-deficit/hyperactivity disorder: A multi-pollutant analysis of a Norwegian birth cohort

Study Purpose: This study investigates if early-life exposure to persistent organic pollutants is associated with an increase risk of attention-deficit/hyperactivity disorder (ADHD).

Study Conclusion: Early-life exposure to B-HCH and PFOS was associated with increased risk of ADHD, with suggestion of sex-specific effects for PFOS. The unexpected inverse associations between per- and perfluoroalkyl DDT and higher HCB levels and ADHD could be due to live birth bias.

Perfluoroalkyl substances in cord blood and attention deficit/hyperactivity disorder symptoms in seven-year-old children

Study Purpose: This study looks at the association between in utero exposure to PFASs and the development of neurobehavioral symptoms (such as ADHD) in early childhood.

Study Conclusion: Prenatal exposure to PFNA was associated with neurobehavioral symptoms related to ADHD among Asian seven-year-old children.

Behavior

Prenatal Exposure to Perfluoroalkyl Substances and Child Behavior at Age 12: A PELAGIE Mother–Child Cohort Study

Study Purpose: The aim of the present study was to assess the association between prenatal exposure to several PFAS and externalizing and internalizing behavior among 12-y-olds. PFAS were studied both individually and as a mixture.

Study Conclusion: Prenatal exposure to PFNA and PFOA were associated with increasing scores for measures of externalizing behaviors, specifically hyperactivity. We also identified associations between PFNA and PFDA prenatal exposure levels and increasing scores related to internalizing behaviors (general anxiety and major depressive disorder), which adds to the as yet sparse literature examining the links between prenatal exposure to PFAS and internalizing disorders.

Prenatal Exposure to Perfluoroalkyl Substances and Cognitive and Neurobehavioral Development in Children at 6 Years of Age

Study Purpose: Evidence on the relationship between prenatal PFAS exposure on neurodevelopment in children is inconclusive. This study evaluates the relationship between prenatal exposure to PFAS and children's neurodevelopment and whether maternal diet and child sex affect this relationship.

Study Conclusion: This study suggests that prenatal exposure to PFAS was associated with more attention problems, and that maternal nut intake during pregnancy may alter this relationship. However, this should be further studied due to the small study population.

Behavioral outcomes and exposure to perfluoroalkyl substances among children aged 6-13 years: The TEDDY child study

Study Purpose: Although some studies report that exposure to PFAS during pregnancy and early life could impact neurodevelopment, there are overall mixed findings. This study assesses the association of risk factors for environmental PFAS exposure and childhood PFAS concentrations with behavioral difficulties among school-aged children exposed to PFAS from birth, while controlling for the influence of the parenting and familial environment.

Study Conclusion: This study observed associations of tap water consumption and child PFOS and PFHxS concentrations with greater behavioral difficulties.

The Association between Prenatal Per- and Polyfluoroalkyl Substances Exposure and Neurobehavioral Problems in Offspring: A Meta-Analysis

Study Purpose: Exposure to PFAS during pregnancy has been suggested to be associated with neurobehavioral problems in offspring. However, current studies on the association between prenatal PFAS exposure and neurobehavioral problems in children, especially ADHD and autism spectrum disorder, are inconsistent. This study aims to summarize and describe the relationship between PFAS exposure during pregnancy and ADHD and autism spectrum disorder in off-spring.

Study Conclusion: In summary, PFOA, PFOS, and PFNA exposure during pregnancy were found to associated with ADHD and autism spectrum disorder in offspring in the highest quartile group. The findings indicate that prenatal PFAS exposure and neurobehavioral problems are not straightforward associations. More research is needed in this area of study.

Associations between prenatal exposure to perfluoroalkyl substances and neurobehavioral development in early childhood: A prospective cohort study

Study Purpose: Findings from epidemiological studies on the associations between prenatal PFAS exposure and children's neurodevelopment were inconclusive. This study aimed to assess the effects of prenatal PFAS exposure on children's neurobehavioral development.

Study Conclusion: Overall, there was not clear evidence that prenatal exposure to PFAS had negative effects on neurobehavioral development in children. However, the modest associations still suggested potential developmental neurotoxicity of prenatal PFAS exposure. 

A Critical Review and Meta-Analysis of Impacts of Per- and Polyfluorinated Substances on the Brain and Behavior

Study Purpose: In this study, they review factors impacting the absorption, distribution, and accumulation of PFAS in the brain, and currently available evidence for neurotoxic impacts defined by disruption of neurochemical, neurophysiological, and behavioral endpoints.

Study Conclusion: Although there is discrepancy across studies, the evidence suggests that PFAS can impact the nervous system, with particularly harmful effects from developmental exposures or exposures in sensitive populations. However, the limitations and inconsistencies in the current research make the severity of the neurotoxicological ramifications of PFAS exposure largely unknown. Most PFAS research is currently focused on PFOS and PFOA, while there are thousands of other compounds that receive very little research focus. 

Prenatal exposure to persistent organic pollutants and metals and problematic child behavior at 3-5 years of age: a Greenlandic cohort study

Study Purpose: High levels of persistent organic pollutants (POPs) and heavy metals are found in Arctic populations. POP and heavy metals are linked to impaired cognitive development. This study examined associations between prenatal POP and metals exposure and problematic child behavior.

Study Conclusion: In this study, they had inconsistent findings on the associations between PFAS and and negative behaviors.

Childhood exposure to per- and polyfluoroalkyl substances (PFAS) and neurobehavioral domains in children at age 8 years

Study Purpose: To examine whether childhood PFAS concentrations are associated with neurobehavior in children at age 8 years and whether child sex modifies this relationship.

Study Conclusion: Findings in this study do not consistently support an association between childhood PFAS serum concentrations and neurobehavior, child sex may play a role in the relationship as well.

Prenatal and childhood exposure to per- and polyfluoroalkyl substances (PFAS) and child executive function and behavioral problems

Study Purpose: In this study, they examine associations of prenatal and childhood PFAS plasma concentrations with parent and teacher assessments of children's behavior problems and executive function abilities at age 6-10.

Study Conclusion: In a birth cohort of U.S. children with PFAS concentrations similar to those of the U.S. general population, prenatal PFAS concentrations were not consistently associated with childhood assessments of behavior and executive function, but we observed cross-sectional associations of childhood PFAS with greater behavioral and executive function problems at ages 6–10. Specifically, PFOA, PFOS, PFHxS, PFNA and PFDA were each associated with more behavioral problems as evaluated by parents using the SDQ, with teacher-rated SDQ scores also suggestively elevated (indicating greater problems) in children with higher PFHxS and PFNA concentrations. Childhood PFOS was associated with greater executive function problems as assessed by parents using the BRIEF, while higher childhood PFHxS was associated with greater teacher-rated executive function problems. We did not observe consistent patterns of sexual dimorphism in associations.

Prenatal exposure to poly- and perfluoroalkyl substances (PFAS) and neurobehavior in US children through 8 years of age: the HOME Study

Study Purpose: Studies of PFAS and ADHD in children are inconsistent. This study examines associations between maternal serum PFAS concentrations and child behavior in mothers and their children.

Study Conclusion: Prenatal PFOS and PFNA were associated with hyperactive-impulsive type ADHD across two tests. PFHxS was associated with increased problems with both externalizing and internalizing behaviors. No associations were noted between PFOA and child neurobehavior.

Behavioral difficulties in 7-year-old children in relation to developmental exposure to perfluorinated alkyl substances

Study Purpose: This study looks at the associations between prenatal, 5 and 7-year-old PFAS exposures and behavioral problems in 7-year-olds.

Study Conclusion: Higher serum PFAS concentrations at ages 5- and 7-years were associated with parent-reported behavioral problems at age 7. No associations were observed between prenatal PFAS concentrations and SDQ scores.

Prenatal Exposure to Perfluoroalkyl Substances and Behavioral Development in Children

Study Purpose: This study explored the relationship between prenatal exposure to several PFASs and behavioral development at the age of 18 months.

Study Conclusion: These findings suggest that higher prenatal exposure to PFOA was related to less externalizing behavior in boys. Results were different for boys and girls. However, more research is needed as this was a small study population.

Autism

Persistent organic pollutants exposure and risk of autism spectrum disorders: A systematic review and meta-analysis

Study Purpose: This study reviews evidence to investigate relationships between persistent organic pollutants, such as PFAS, and autism spectrum disorder.

Study Conclusion: This research provided evidence that exposure to certain PCB chemicals may be associated with an increased risk of autism. The available evidence did not sufficiently establish an association between the exposure to other environmental chemicals, such as PFAS, and an increased risk of autism.

Early-life exposure to endocrine-disrupting chemicals and autistic traits in childhood and adolescence: a systematic review of epidemiological studies

Study Purpose: Exposure to PFAS and other environmental chemicals during critical neurodevelopmental windows has been associated with the risk of autistic traits. This article reviews the existing studies that examine the association between maternal exposure to environmental chemicals during pregnancy and the risk of autism spectrum disorder (ASD) in children.

Study Conclusion: Findings from the studies evaluated here do not support an association between prenatal exposure to environmental chemicals and the likelihood of autistic traits later in life. However, there are few studies in this area, so this may require further study.

Prenatal exposure to per- and polyfluoroalkyl substances and childhood autism-related outcomes

Study Purpose: Epidemiologic evidence linking prenatal exposure to PFAS with altered neurodevelopment is inconclusive, and few large studies have focused on autism-related outcomes. This study investigates whether blood concentrations of PFAS in pregnancy are associated with child autism-related outcomes.

Study Conclusion: Prenatal blood concentrations of PFNA may be associated with modest increases in child autism-related traits. 

Prenatal Exposure to Per- and Polyfluoroalkyl Substances, Maternal Thyroid Dysfunction, and Child Autism Spectrum Disorder

Study Purpose: This review evaluates and summarizes potential mechanisms of PFAS on maternal thyroid dysfunction, which could increase prevalence of autism spectrum disorder. 

Study Conclusion: To date, studies have not examined a potential pathway from prenatal PFAS exposure through thyroid dysfunction to autism spectrum disorder (ASD) development. Iodine deficiency is associated with an increased risk of hypothyroidism and is known to cause brain damage. However, most studies have failed to measure important biomarkers that might affect maternal thyroid function, such as iodine status or thyroid antibodies. This review highlights that more rigorous studies are needed to yield robust and generalizable information about this potential pathway. The evidence on mechanisms of this pathway summarized in this review suggests that thyroid dysfunction could mediate a relationship between prenatal PFAS exposure and child ASD, and this potential mediation effect could help explain only three of seven studies finding an association between PFAS exposure and child ASD.

Childhood exposure to per- and polyfluoroalkyl substances and neurodevelopment in the CHARGE case-control study

Study Purpose: PFAS are shown to have neurotoxic effects on animals, but human evidence for associations between childhood PFAS exposure and neurodevelopment is inconclusive. This study examines if childhood PFAS concentrations are associated with a diagnosis of autism spectrum disorder, developmental delay, or other early concerns in development.

Study Conclusion: In the case-control study, childhood PFOA, PFHpA, and a PFAS mixture were associated with increased odds of autism, while PFUnDA was associated with decreased odds of autism. Further study is needed.

Prenatal exposure to per- and polyfluoroalkyl substances (PFAS) and associations with attention-deficit/hyperactivity disorder and autism spectrum disorder in children

Study Purpose: This study investigates whether prenatal exposure to PFAS was associated with childhood diagnosis of ADHD or autism spectrum disorder (ASD).

Study Conclusion: Prenatal exposure to PFOA was associated with increased risk of autism and ADHD in children. For some PFAs, there were inverse associations. The findings linking PFAS with neurodevelopment are still inconclusive.

Prenatal exposure to per- and polyfluoroalkyl substances in association with autism spectrum disorder in the MARBLES study

Study Purpose: Prenatal exposure to PFASs has shown to potentially impact child brain development, but evidence is still inconsistent. This study looks at whether prenatal exposure to PFAS was associated with increased risk of autism.

Study Conclusion: In this high risk autism group, there was an increased risk of autism in children exposed to PFOA and PFNA.

Modeled prenatal exposure to per- and polyfluoroalkyl substances in association with child autism spectrum disorder: A case-control study

Study Purpose: This study looks at the associations between prenatal maternal exposure to PFAS with child diagnosis of autism.

Study Conclusion: In analyses where modeled prenatal maternal PFAS serum concentrations served as in utero exposure, it was observed that prenatal PFHxS and PFOS exposure were borderline associated with increased odds of child diagnosis of ASD. No associations were observed for other PFAS.

Other

The Influence of Adiposity Levels on the Relation between Perfluoroalkyl Substances and High Depressive Symptom Scores in Czech Adults

Study Purpose: Our goal is to examine the association between plasma PFAS levels and depression prevalence in a representative population-based sample of adults and older adults.

Study Conclusion: The present analysis suggests a distinctive association between PFAS levels in the blood and the prevalence of depression. Remarkably, among the four analyzed PFAS compounds, perfluorooctanoic acid (PFOA) emerged as the sole significant association before adjustments for adiposity levels. However, subsequent stratified analyses revealed that PFOA, along with perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA),demonstrated associations exclusively in individuals with a normal amount of adiposity.

Health and Psychological Concerns of Communities Affected by Per- and Poly-Fluoroalkyl Substances: The Case of Residents Living in the Orange Area of the Veneto Region

Study Purpose: The purpose of the study is to investigate the health and psychological concerns of communities affected by Per- and Poly-Fluoroalkyl Substances (PFAS) contamination in the Veneto Region.

Study Conclusion: The present study contributes to the literature by providing an account of the experiences of some of the residents exposed to PFAS contamination in the Veneto Region of Italy. The aim was to describe the experience of residents living in the territories of the Orange Area, the second area in terms of PFAS exposure, who experienced exclusion from HBM and a significant negative impact on their well-being.

Correlation analysis between per-fluoroalkyl and poly-fluoroalkyl substances exposure and depressive symptoms in adults: NHANES 2005–2018

Study Purpose: Excessive exposure to per and poly-fluoroalkyl compounds (PFAS) can lead to various negative health effects. However, there’s a lack of research studying the link between PFAS exposure and depression inadults, and the existing findings are inconsistent.

Study Conclusion: This study focused on adults aged 18 and above drawn from the NHANES survey spanning the years 2005 to 2018, aiming to delve into the potential link between individual PFOA, PFHxS, and PFUnDA exposure as well as combined PFAS exposure and the occurrence of depressive symptoms. Our findings highlighted a noteworthy trend—elevated levels of individual PFAS exposure and combined PFAS
exposure among adults aged 18 and older were associated with a decreased likelihood of experiencing depressive symptoms.

Exposure to per- and polyfluoroalkyl substances in early pregnancy and risk of cerebral palsy in children

Study Purpose: This study investigates the association between prenatal PFAS exposure and cerebral palsy in children.

Study Conclusion: This study found little evidence to suggest that early pregnancy prenatal exposure to PFHxS, PFOA, PFNA, or PFOS increases the risk of cerebral palsy. However, these findings warrant further study.

Maternal co-exposure to mercury and perfluoroalkyl acid isomers and their associations with child neurodevelopment in a Canadian birth cohort

Study Purpose: This study aimed to examine associations between prenatal exposure to 25 PFAS and child neurodevelopment and to consider the influence of total mercury on these associations.

Study Conclusion: These findings suggest adverse effects of maternal PFAS exposure during pregnancy on child neurodevelopment. 

Association between prenatal or early postnatal exposure to perfluoroalkyl substances and language development in 18 to 36-month-old children from the Odense Child Cohort

Study Purpose: Findings of impaired neurodevelopment after prenatal exposure to PFAS are mixed and few studies have assessed the impact of postnatal exposure. Language development is a good marker of neurodevelopment but few studies have investigated this outcome separately. This study investigated the association between prenatal and early postnatal PFAS exposure and delayed language development in 18 to 36-month-old children.

Study Conclusion: This study did not observe associations between early postnatal PFAS exposure and language development, but they were not able to separate the adverse effects of PFAS exposure from the positive effects of breastfeeding on neurodevelopment. 

Prenatal exposure to legacy PFAS and neurodevelopment in preschool-aged Canadian children: The MIREC cohort

Study Purpose: This study aimed to evaluate associations between prenatal exposure to legacy PFAS and children's IQ and executive functioning and to determine if these associations are different between girls and boys.

Study Conclusion: Higher prenatal PFAS levels were associated with lower performance IQ in male offspring.

Associations of prenatal exposure to per- and polyfluoroalkyl substances (PFAS) with measures of cognition in 7.5-month-old infants: An exploratory study

Study Purpose: Prenatal exposure to PFAS has been linked to an array of health outcomes. This study examines whether prenatal exposure to a mixture of PFAS was related to cognition in 7.5 month old infants.

Study Conclusion: In this population, prenatal PFAS exposure was modestly associated with an increase in shift rate, or the number of times infants looked between stimuli (a measure of attention). Exposure was not strongly associated with any adverse cognitive incomes in 7.5-month-old infants.

Association between prenatal and early postnatal exposure to perfluoroalkyl substances (PFAS) and IQ score in 7-year-old children from the Odense Child Cohort

Study Purpose: PFAS are persistent chemicals that may affect brain development. This study investigates whether prenatal or early postnatal PFAS exposure was associated with IQ-scores in schoolchildren in Denmark between 2010 to 2020.

Study Conclusion: Prenatal PFAS exposure was associated with lower IQ scores in 7-y-old children, specifically PFOS and PFNA. Due to the strong correlation between duration of breastfeeding and child PFAS at this age, it was not possible to differentiate the opposite effects of PFAS exposure and duration of breastfeeding on IQ. More studies on PFAS exposure and cognitive development are needed in which PFAS exposure is measured at a later age. 

Prenatal exposure to perfluoroalkyl substances and child intelligence quotient: Evidence from the Shanghai birth cohort

Study Purpose: Human evidence on the association between prenatal exposure to PFAS and child IQ remains unclear. In this study, researchers investigate whether prenatal exposure to PFAS is associated with IQ in offspring.

Study Conclusion: Exposure to PFAS mixtures during early pregnancy were not associated with offspring IQ. For certain individual PFAS, there were inverse associations with IQ. Considering the evidence is still inconsistent, further research is needed to confirm these findings.

Prenatal Exposure to Legacy and Alternative Per- and Polyfluoroalkyl Substances and Neuropsychological Development Trajectories over the First 3 Years of Life

Study Purpose: The neurotoxic effects of prenatal exposure to PFAS in animals are well-documented. In this study, 17 PFAS chemicals were measured in pregnant mothers and neuropsychological development was assessed at 3, 6, 12, 18, 24, and 36 months.

Study Conclusion: Evidence from the present study indicates that prenatal exposure to PFAS is positively associated with higher risks of persistently low neuropsychological development trajectories over the first 3 years of life. Identifying the critical window for PFAS exposure and neuropsychological development is required for the next step.

Associations of prenatal PFAS exposure and early childhood neurodevelopment: Evidence from the Shanghai Maternal-Child Pairs Cohort

Study Purpose: This study assesses children's neurodevelopment at 2, 6, 12, and 24 months of exposure and evaluates the relationship between neurodevelopment and PFAS exposure.

Study Conclusion: In conclusion, we found that exposure to legacy long-chain PFAS (PFOA, PFOS, PFNA, and PFDA), short-chain PFAS (PFHxS), and novel alternatives (6:2Cl-PFESA) were associated with an increased risk of impaired communication domain development, especially in boys, on basis of multiple PFAS and repeated neurodevelopment measurements. PFOA, PFOS, and PFHxS can even affect the communication domain's trajectory throughout the whole infancy. The impacts of PFAS mixtures on the development of the communication domain were substantially greater than the effects induced by individual PFAS. Further research is needed to confirm these findings.

Developmental language disorders in preschool children after high exposure to perfluoroalkyl substances from contaminated drinking water in Ronneby, Sweden

Study Purpose: There are indications that early-life exposure to PFAS can impact neurodevelopment, but results are inconclusive. The objective of this study was to investigate if high early-life exposure to PFHxS and PFOS increases the risk of developmental language disorders in children up to 7 years of age.

Study Conclusion: Children, particularly girls, with high exposure had an increased risk of both referral to a speech-language pathologist and confirmed developmental language disorders. Further research is needed to confirm these findings.

Prenatal perfluoroalkyl substances exposure and neurodevelopment in toddlers: Findings from SMBCS

Study Purpose: Prenatal PFAS exposure has been reported to affect neurodevelopment, though evidence is inconsistent. This study aimed to evaluate the associations between cord serum PFAS concentrations and neurodevelopment in toddlers from 1 to 3 years age.

Study Conclusion: This study found that higher prenatal PFAS exposure were associated with decreased development quotient scores as well as elevated odds for low-score neurodevelopment trajectory. These findings suggest that prenatal exposure to PFAS may adversely affect neurodevelopment in toddlers. Further study is needed to confirm these findings.

Exposure to perfluoroalkyl substances and neurodevelopment in 2-year-old children: A prospective cohort study

Study Purpose: As the fetal stage is a critical window for neurodevelopment, it is important to know if in utero exposure to PFAS affects fetal neurodevelopment. This study investigates the relationship between PFAS exposure during early pregnancy and the neurodevelopmental status at 2 years of age.

Study Conclusion: PFAS exposure during early pregnancy was significantly associated with the adverse neurodevelopmental status at 2 years of age.

In utero exposure to perfluoroalkyl and polyfluoroalkyl substances and attention and executive function in the offspring: A study in the Danish National Birth Cohort

Study Purpose: PFAS are suspected to affect the neuropsychological function of children, but only few studies have evaluated the association with childhood attention and executive function. To investigate the association between intrauterine exposure to PFAS and offspring attention and executive function.

Study Conclusion: Intrauterine exposure to PFOSA was associated with poorer selective attention, while PFOA was associated with poorer executive function. Given the widespread nature of PFAS exposure, these findings may have public health implications, warranting further investigation.

Perfluorooctanoate and perfluorooctane sulfonate in umbilical cord blood and child cognitive development: Hamamatsu Birth Cohort for Mothers and Children (HBC Study)

Study Purpose: Prenatal exposure to PFAS has been shown to affect offspring behaviors in laboratory animals. Several epidemiological studies investigated associations between prenatal PFAS exposure and child neurodevelopment, but results were inconclusive. This paper examines the associations between cord blood concentrations of PFOA and PFOS and cognitive development in children from 4 to 40 months of age.

Study Conclusion: In this study, cord blood PFOA and PFOS concentrations showed mixed associations with child cognitive functions at specific age but had positive associations with longitudinal changes in cognitive development from 4 to 40 months of age.

Prenatal exposure to per- and polyfluoroalkyl substances, fetal thyroid hormones, and infant neurodevelopment

Study Purpose: PFAS are believed to impair early neurodevelopment and disrupt thyroid hormone levels. However, there are limited epidemiological data on the neurodevelopmental effects in infancy of prenatal PFAS exposure and how thyroid hormones may impact this. This study evaluates the potential associations between prenatal PFAS exposure and early neurodevelopmental deficiencies and how thyroid hormones may affect these associations.

Study Conclusion: PFBS and PFHxS were negatively associated with early neurodevelopment, especially for gross motor development. These associations were partially explained by TSH and FT4 levels.

Impaired gross motor development in infants with higher PFAS concentrations

Study Purpose: In this study, they investigate PFAS concentrations in mothers at 6 points during and after pregnancy and in infants at six months and studied the effects of PFAS status on infant gross motor development at age six months.

Study Conclusion: This study found associations between maternal PFAS concentrations in pregnancy week 18 and infant PFAS concentrations at age six months. While the concentrations declined in the mothers during pregnancy and postpartum, the highest concentrations were seen in infants aged six months. Parity and fish intake were strong predictors of maternal PFAS status, while maternal concentrations of PFAS in pregnancy week 18 and months of exclusive breastfeeding determined the PFAS concentrations in infants at six months. Infants who scored below the median on gross motor development had higher PFAS concentrations than infants with a better gross motor development. A higher maternal fish intake in pregnancy week 18 was additionally associated with a poorer motor score in the infants at six months. Infant gross motor development is a marker of later cognitive outcome and our findings indicate that a high concentration of PFASs in young infants may be a risk factor for impaired neurodevelopment.

Perinatal exposure to endocrine disrupting chemicals and neurodevelopment: How articles of daily use influence the development of our children

Study Purpose: This review focuses on data from human studies and animal studies to examine the impact of EDCs after a gestational or lactational exposure to endocrine disrupting chemicals (EDCs, like PFAS), and how they may impact the immune system and/or neurodevelopment

Study Conclusion: Developmental exposure to endocrine disrupting chemicals (EDCs) can permanently alter developmental programs, including those that wire the brain. Of emerging interest is how these chemicals may also affect the immune response, given the cross-talk between the endocrine and immune systems. As brain development is strongly dependent on hormones, this complicated interplay may have long-lasting neurodevelopmental consequences.

Prenatal perfluoroalkyl substance exposure and neuropsychological development throughout childhood: The INMA Project

Study Purpose: This study evaluates the associations between prenatal PFAS exposure and neuropsychological development in childhood.

Study Conclusion: This study showed no clear-cut evidence of an association between prenatal PFAS exposure and adverse neuropsychological development in children up to the age of 7 years.

Exposure to Perfluoroalkyl Substances During Pregnancy and Fetal BDNF Level: A Prospective Cohort Study

Study Purpose: Brain-derived neurotrophic factor (BDNF) is an important factor in neurodevelopment, but its role in PFAS-induced neurotoxicity is unclear. This study investigates the association between prenatal PFAS exposure and fetal BDNF level in the umbilical cord blood.

Study Conclusion: Prenatal exposure to PFHxS was associated with an increased BDNF level in the umbilical blood, especially in male fetuses.

Chemical Mixture Exposures During Pregnancy and Cognitive Abilities in School-Aged Children

Study Purpose: Gestational exposure to chemical mixtures, which is prevalent among pregnant women, may be associated with adverse childhood neurodevelopment. However, few studies have examined relations between gestational chemical mixture exposure and children's cognitive abilities.

Study Conclusion: In this study, combined prenatal exposure to phenols, some phthalates, pesticides, and PFASs were inversely associated with children's cognition

Prenatal exposure to per- and polyfluoroalkyl substances and cognitive development in infancy and toddlerhood

Study Purpose: PFAS have shown neurobehavioral toxicity in experimental studies. Evidence on associations between prenatal PFAS exposure and child's cognitive development is inconsistent partly due to differences in assessment time points and tools used. This study examines associations of prenatal maternal serum PFAS concentrations with child's cognitive development assessed at multiple time points in infancy and toddlerhood.

Study Conclusion: Prenatal PFOA appears to negatively affect child's cognitive development in toddlerhood in this study population. Because a large number of the children in this study were at risk for atypical development, studies in the general population are needed to confirm findings.

Perfluoroalkyl chemicals in neurological health and disease: Human concerns and animal models

Study Purpose: This study summarized previous literature on PFAS impacts on neurobiological, neuroendocrine, and neurobehavioral outcomes.

Study Conclusion: This study found that there are many mechanisms through which PFASs may enter the brain and interact to impact neurological function.

The association between prenatal exposure to perfluoroalkyl substances and childhood neurodevelopment

Study Purpose: This study looks at the association between prenatal PFAS exposure and child cognitive outcomes at 5 different points in time. The population in this study was prenatally exposed to the World Trade Center disaster, where many pollutants including PFASs were released.

Study Conclusion: These results suggest a sex- and PFAS-specific between relationship between prenatal PFAS exposures and child neurodevelopment.

Childhood perfluoroalkyl substance exposure and executive function in children at 8 years

Study Purpose: This study tests whether prenatal and childhood exposure to PFAS are associated with cognitive abilities at 8 years old and whether this varies between boys and girls.

Study Conclusion: PFNA and PFOA at 8 years, but not 3 years, may be related to poorer executive function.        

Prenatal Exposure to Perfluoroalkyl Substances and IQ Scores at Age 5: A Study in the Danish National Birth Cohort

Study Purpose: This study looks at whether prenatal exposure to PFASs is associated with IQ in children.

Study Conclusion: Overall, there was no consistent evidence to suggest PFAS exposure is associated with child IQ scores at 5 years of age.

Prenatal and childhood exposure to per- and polyfluoroalkyl substances (PFASs) and child cognition

Study Purpose: Per- and polyfluoroalkyl substances (PFASs) are suspected developmental toxicants, but epidemiological evidence on neurodevelopmental effects of PFAS exposure is inconsistent.       

Study Conclusion: Suggested associations of prenatal and childhood PFAS exposure with lower childhood visual motor abilities. Other results were inconsistent, with higher prenatal PFASs associated in some cases with better cognitive outcomes.

Prenatal and childhood perfluoroalkyl substances exposures and children’s reading skills at ages 5 and 8 years

Study Purpose: This study looks at the association between prenatal and early childhood levels of PFAS with children's reading skills at ages 5 and 8 years old.

Study Conclusion: Prenatal and childhood serum PFOA, PFOS and PFNA concentrations were positively associated with better children’s reading skills at ages 5 and 8 years. No association was found between serum PFHxS and reading skills.

Exposure to Perfluorinated Alkyl Substances and Health Outcomes in Children: A Systematic Review of the Epidemiologic Literature

Study Purpose: This study summarized previous studies looking at the relationships between childhood exposure to PFAS and health outcomes in children.

Study Conclusion: There were inconsistent findings on associations between PFAS and neurodevelopmental outcomes.

 

Kidney and Liver Function

 

Urinary System

Kidneys work with other components of the urinary system to filter toxins and waste from the blood and eliminate them from the body. The Kidney section includes information on kidney function, hyperuricemia, gout, and chronic kidney disease as they relate to PFASs. It includes 25 total studies; 20 were published in the last 6 years. Although a study may find, or not find, an association between PFASs and kidney outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Urinary System

Novel Insights into the Adverse Health Effects of per- and Polyfluoroalkyl Substances on the Kidney via Human Urine Metabolomics

Study Purpose: The objective was to identify whether urine can be used as a
biomonitoring matrix of PFAS exposure and whether urine metabolomics is indicative of renal function.

Study Conclusion: In summary, eight differential metabolites were found in urine metabolomics, which were revealed to be involved in
amino acid metabolism, steroid biosynthesis, and enterohepatic circulation. The result of this study shows that adverse kidney effects may exist in high-PFAS exposure workers.

The association of perfluoroalkyl substances (PFAS) exposure and kidney function in Korean adolescents using data from Korean National Environmental Health Survey (KoNEHS) cycle 4 (2018-2020): a cross-sectional study

Study Purpose: PFAS exposure may affect kidney function, but there are no studies on the effect of PFAS on kidney function through human studies in Korea. Using Korean national data, the relationship between PFAS blood levels and kidney function was analyzed in adolescents. 

Study Conclusion: In this study of Korean adolescents, there was a negative relationship between PFOA, PFOS, PFHxS, PFNA, and PFDeA and their combinations, and kidney function. 

Exposure to perfluoroalkyl and polyfluoroalkyl substances and estimated glomerular filtration rate in adults: a cross-sectional study based on NHANES (2017-2018)

Study Purpose: PFAS exposure may affect kidney function. This study aimed to investigate the relationships between PFAS and kidney function, measured through glomerular filtration rate (GFR).

Study Conclusion: This study used national data from 2017-2018 to fit models to assess the relationship between concentrations of 6 PFAS and GFR levels. PFOS and PFHxS concentrations were associated with GFR. PFHxS and PFDeA/PFNA/PFUA had a significant joint effect on GFR. 

The Relationship between Typical Environmental Endocrine Disruptors and Kidney Disease

Study Purpose: Endocrine disrupting chemicals (EDCs) such as PFAS can alter endocrine functions that result in adverse effects on growth and development, metabolism, and reproductive function. The kidney is an important organ in the urinary system and an accumulation point. Studies have shown that EDCs can cause proteinuria, which affects parts of the kidney, and even leads to diabetes and renal fibrosis in human and animal studies. This review discusses kidney accumulation of EDCs such as PFAS and explains how exposure to EDCs can cause kidney conditions.

Study Conclusion: This review summarizes the effects of EDCs on kidneys. EDCs can cause proteinuria, affect kidney processes, disrupt balance, and activate pathways that can result in kidney injury and renal fibrosis. More study is needed in this area. 

Joint effects of per- and polyfluoroalkyl substance alternatives and heavy metals on renal health: A community-based population study in China

Study Purpose: Previous studies have indicated that chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs), when used as an alternative to PFAS, result in kidney toxicity. However, their co-exposure with heavy metals has not been investigated. This study explores the joint effects of Cl-PFESAs and heavy metal exposure on renal health in Chinese adults and to identify specific chemicals driving these associations.

Study Conclusion: These results indicate that exposure to both traditional and novel pollutants was negatively associated with glomerular filtration rate and positively correlated with the presence of chronic kidney disease, especially in women. In models, PFOS and Arsenic were the primary contributors to reduced glomerular filtration rate, and arsenic was the principal factor in the association with chronic kidney disease. More studies are needed to confirm these findings.

Association between exposure to perfluoroalkyl substances and uric acid in Chinese adults

Study Purpose: This study investigates the association between PFAS exposure and uric acid levels. 

Study Conclusion: Significant associations between PFOA and PFDA and uric acid, and between PFOA and hyperuricemia were found in the single-pollutant models, but the joint effect of PFASs mixture on uric acid was not observed in the BKMR model, which provided new insights in regulation policies and risk assessment of PFASs. 

Serum concentrations of perfluoro-1-heptane sulfonate (PFHpS) among US adults: variabilities across different stages of kidney function

Study Purpose: National data from 2017-2018 were analyzed for gender and racial/ethnic differences for PFHpS for US adults aged 20 years or older. In addition, variability in adjusted concentrations across various stages of glomerular filtration rate (GFR) was also studied. 

Study Conclusion: Adjusted concentrations of PFHpS across deteriorating kidney function were located on inverted U-shaped curves for all participants, males, and females. Future studies should evaluate the role of PFHpS exposure on other organ systems. 

Associations of exposure to perfluoroalkyl substances with serum uric acid change and hyperuricemia among Chinese women: Results from a longitudinal study

Study Purpose: Cross-sectional studies have reported associations of PFOA with serum uric acid levels. However, the associations of other commonly detected PFASs with serum uric acid and hyperuricemia remain unclear.

Study Conclusion: These findings suggest exposure to PFASs as a risk factor for hyperuricemia and shed light on the need for hyperuricemia prevention for elderly females.

Co-exposure to perfluoroalkyl acids and heavy metals mixtures associated with impaired kidney function in adults: A community-based population study in China

Study Purpose: Previous studies have separately linked either PFAS or heavy metal exposure with kidney disfunction. This study explores the associations between exposure to PFAS and heavy metals mixtures and kidney function in adults.

Study Conclusion: Co-exposure to PFAS and heavy metals mixtures was associated with reduced kidney function in adults and PFHpS, Arsenic, and Strontium appeared to be the major contributors.

Associations between the concentrations of α-klotho and selected perfluoroalkyl substances in the presence of eGFR based kidney function and albuminuria: Data for US adults aged 40-79 years

Study Purpose: Exposures to PFAS cause oxidative stress, a risk factor for tissue damage leading to kidney and cardiovascular diseases. The antiaging protein klotho is an anti-oxidative agent, and how klotho homeostasis interacts with PFAS has not been reported. This study among 3981 US adults evaluates relationships of internal PFAS contamination to alpha-klotho across stages of GFR kidney function and albuminuria. 

Study Conclusion: This study found a modest association of PFAS exposure to lower serum klotho that is evident only in the healthy kidney and that disappears when there is either albuminuria or diminished glomerular filtration. This association actually reverses in moderate-severe renal failure. 

Serum concentrations of per-/polyfluoroalkyl substances and its association with renal function parameters among teenagers near a Chinese fluorochemical industrial plant: A cross-sectional study

Study Purpose: Currently, studies on the association between PFAS concentrations and the renal function of residents, especially teenagers, living near fluorochemical production plants, are relatively rare. In this study, local teenagers (11-15) were included.

Study Conclusion: In this study, the serum concentrations of 18 PFAS in 775 teenagers were measured, and an extremely high PFOA concentration was observed, 10-1000 times higher than that in general areas. The prevalence of chronic kidney disease was relatively high, much higher than the general population.

Associations between serum PFOA and PFOS levels and incident chronic kidney disease risk in patients with type 2 diabetes

Study Purpose: This study investigates the associations of PFOA and PFOS exposure and chronic kidney disease among type 2 diabetes patients.

Study Conclusion: This study found a significant negative association between serum PFOS concentrations and incidence chronic kidney disease risk in patients with diabetes. However, we should interpret these findings with caution, as the relationship between kidney function and PFAS concentrations is complex and more studies are needed to further investigate these findings.

Metabolome-wide association study of serum exogenous chemical residues in a cohort with 5 major chronic diseases

Study Purpose: This study investigates the linkages between serum chemical concentrations and 5 chronic diseases including obesity, hyperuricemia, hypertension, diabetes, and dyslipidemia, and further reveals the metabolic perturbations of chronic diseases related to chemical exposure, then gain potential mechanism insight.

Study Conclusion: This study demonstrated a positive association between PFAS exposure and hyperuricemia. The most significant metabolic abnormality was lipid metabolism which was not only positively associated with PFASs, but also increased the risk of hyperuricemia.

Perfluoroalkyl substances (PFASs) exposure and kidney damage: Causal interpretation using the US 2003-2018 National Health and Nutrition Examination Survey (NHANES) datasets

Study Purpose: The objective of this study was to test the hypothesis that increased concentrations of PFASs cause kidney damage.

Study Conclusion: This study evaluated the relationship between increased concentrations of 4 PFASs and kidney damage. The hypothesis of PFAS-induced kidney damage was plausible based on the results. Further studies are required.

Per- and polyfluoroalkyl substances and kidney function: Follow-up results from the Diabetes Prevention Program trial

Study Purpose: To determine associations of plasma PFAS concentrations and glomerular filtration rate (GFR - a measure of kidney function) and evaluate whether a lifestyle intervention changes these associations.

Study Conclusion: Among adults with prediabetes, higher concentrations of PFASs were associated with lower GFR over approximately 14 years. A lifestyle intervention of diet and exercise did not modify this association. Individuals with hypertension may experience a more detrimental effect.

Impact of kidney hyperfiltration on concentrations of selected perfluoroalkyl acids among US adults for various disease groups

Study Purpose: National data from 2003-2016 for US adults were analyze to evaluate the impact of kidney hyperfiltration on the levels of PFASs.

Study Conclusion: This study observed that participants with hypertension had the highest PFAS levels, regardless the filtration rate of their kidneys. Those with anemia had the lowest PFAS levels.

Perfluoroalkyl acids, hyperuricemia and gout in adults: Analyses of NHANES 2009-2014

Study Purpose: This study investigates whether there is an association between levels of PFASs and gout, uric acid levels, or hyperuricemia.

Study Conclusion: There was an association between select PFAS and self-reported gout. There was also an association between several PFAS and hyperuricemia.

Dynamics of associations between perfluoroalkyl substances and uric acid across the various stages of glomerular function

Study Purpose: Hyperuricemia (elevated uric acid levels) is associated with increased risk of high blood pressure, metabolic syndrome, and future cardiovascular disease. This study looks at the associations between PFAs and uric acid levels across various levels of kidney function.

Study Conclusion: Increasing levels of every measured PFAS except PFHxS was found to increase levels of uric acid.

Perfluoroalkyl substances and kidney function in chronic kidney disease, anemia, and diabetes

Study Purpose: This study looks at the relationship between PFAS and kidney function and how this relationship varies with diabetes and anemia status.

Study Conclusion: PFAS were inversely associated with kidney function in chronic kidney disease patients and diabetics (increased PFAS levels had better kidney function)

Associations between longitudinal serum perfluoroalkyl substance (PFAS) levels and measures of thyroid hormone, kidney function, and body mass index in the Fernald Community Cohort

Study Purpose: This study looks at the association between PFAS and indicators of thyroid disruption, kidney function, and BMI.

Study Conclusion: PFAS levels were associated with altered kidney and thyroid function.

Positive associations of serum perfluoroalkyl substances with uric acid and hyperuricemia in children from Taiwan

Study Purpose: Hyperuricemia (elevated uric acid levels) is associated with increased risk of high blood pressure, metabolic syndrome, and future cardiovascular disease. This study looks at the risk of hyperuricemia after exposure to PFASs

Study Conclusion: PFOA was found to be associated with elevated levels of uric acid in children, especially boys.

 

Liver

The Liver section includes information on liver disease in adults and children, non-alcoholic fatty liver disease, and liver function as they relate to PFASs. It includes 25 total studies; 23 studies were published in the last 6 years. Although a study may find, or not find, an association between PFASs and liver outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Liver

 

The Association of Perfluoroalkyl Substance Exposure and a
Serum Liver Function Marker in Korean Adults

Study Purpose: PFAS and liver disease. In addition, regulations on PFAS in Korea are delayed compared to developed countries, such as Europe and the United States, and public interest is insufficient compared to others. Therefore, we would like to investigate the exposure of Koreans to PFAS in the blood and examine the relationship between these substances and markers
of liver function (AST, ALT, and GGT).

Study Conclusion: We found that serum PFAS concentrations were positively correlated with some liver function markers, such as AST, ALT, and GGT. However, this result differs according to sex, obesity, and type of PFAS. In the case of women, the results were generally more sensitive to exposure to most PFAS than men. In addition, the non-obese group generally showed more sensitive results to exposure to most PFAS. Long-term, well-designed longitudinal
studies and continuous follow-up are needed.

 

Association of per- and polyfluoroalkyl substances with hepatic steatosis
and metabolic dysfunction-associated fatty liver disease among patients
with acute coronary syndrome

Study Purpose: This study will help us provide a reasonable opportunity to hypothesize mechanisms behind comorbidity of hepatic steatosis among ACS patients and provide evidence for tertiary prevention of ACS.

Study Conclusion: In conclusion, we demonstrated that plasma PFOS, PFHxS and total PFAS concentrations were associated with higher hepatic steatosis index
and risk of MAFLD among ACS patients. Mixture analysis observed significant positive association between PFAS mixtures and HSI. Moreover, overall results of PFAS congeners and mixture analysis highlighted the crucial role of PFOS on hepatic steatosis among ACS patients.

Dietary exposure to per- and polyfluoroalkyl substances: Potential health 
impacts on human liver

Study Purpose: This study summarized the source and fate of PFAS, and reviewed the occurrence of PFAS in food system (natural and processed food).
Subsequently, the characteristics of human dietary exposure PFAS (population characteristics, distribution trend, absorption and distribution) were mentioned.

Study Conclusion: Per- and polyfluoroalkyl substances (PFAS), dubbed “forever chemicals”, are environmental pollutant which could penetrate into the food system, increasing the risk of human dietary exposure. More importantly, epidemiological studies have shown that PFAS levels in human serum are closely related to dietary habits, and PFAS exposure may worsen the development of liver disease. 

Close association of PFASs exposure with hepatic fibrosis than steatosis: evidences from NHANES 2017-2018

Study Purpose: This study was performed to evaluate whether exposed to PFAS impacts the occurrence of nonalcoholic fatty liver disease (NAFLD).

Study Conclusion: This study suggests that PFAS exposure did not significantly change the risk of developing non-alcoholic fatty liver disease. PFAS exposure however appears to be more closely associated with hepatic fibrosis.

Associations between per- and polyfluoroalkyl substances, liver function, and daily alcohol consumption in a sample of U.S. adults

Study Purpose: This study aimed to evaluate the association of PFAS with liver function and evaluate whether alcohol intake affects this relationship. 

Study Conclusion: Like other studies, this study found increasing levels of PFOA, PFHxS, and PFNA to be associated with higher levels of ALT. A weak association between increased levels of some PFAS and total bilirubin was also observed.

Firefighters and the liver: Exposure to PFAS and PAHs in relation to liver function and serum lipids (CELSPAC-FIREexpo study)

Study Purpose: Firefighters can be exposed to PFAS, and exposure is suspected to affect liver function and lipid levels. This study investigates the relationship between PFAS exposure and liver function and lipid levels in firefighters.

Study Conclusion: This study observed a mixture of PFAS to increase bilirubin and alter serum lipids. 

Sex-specific effect of perfluoroalkyl substances exposure on liver and thyroid function biomarkers: A mixture approach

Study Purpose: This study investigates the effects of PFAS on liver and thyroid function and differences between sexes.

Study Conclusion: This study observed positive associations between exposure to single PFAS and groups of PFASs and the liver biomarkers ALT and GGT levels in adults, though these associations were only in significant in males.

Perfluoroalkyl substance (PFAS) exposure and risk of nonalcoholic fatty liver disease in the elderly: results from NHANES 2003-2014

Study Purpose: This study aimed to investigate the association between PFAS exposure and the risk of nonalcoholic fatty liver disease (NAFLD) in the elderly.

Study Conclusion: This study showed an association between PFOA/PFNA exposure and NAFLD. The associations were stronger for participants with higher socioeconomic status or inactive lifestyles. 

The association between endocrine disrupting chemicals and MAFLD: Evidence from NHANES survey

Study Purpose: Previous study on the association of endocrine-disrupting chemicals (EDCs), such as PFAS, with metabolic dysfunction-associated fatty liver disease (MAFLD) are very limited. This study analyzed the association of EDCs exposure with MAFLD among American adults.

Study Conclusion: This research suggests that exposure to EDCs (including heavy metals and PFAS) may be linked to MAFLD. Females, participants with hepatitis, and people over the age of 65 are most vulnerable to be effected by EDCs on MAFLD. 

Association between maternal exposure to per- and polyfluoroalkyl substances and serum markers of liver function during pregnancy in China: A mixture-based approach

Study Purpose: Previous studies have shown that PFAS may have toxic effects in the livers of animals. However, evidence in humans is limited, especially in pregnant women. This study aimed to assess the association of PFAS exposure with markers of liver function in pregnant women.

Study Conclusion: In summary, PFBS exposure was associated with increased maternal serum GGT levels and PFHxS exposure was associated with increased maternal serum TBIL and IBIL levels. In contrast, PFHpA exposure was associated with decreased serum TBIL levels. The association of PFUnA with liver enzymes was complex. A mixture of nine PFAS was significantly positively associated with GGT levels in pregnant women, with PFBS identified as the main contributor.

Association of per- and polyfluoroalkyl substance exposure with fatty liver disease risk in US adults

Study Purpose: This study evaluates the association between PFAS levels and fatty liver disease risk in adults.

Study Conclusion: Higher serum PFAS was moderately associated with fatty liver disease risk and worse liver function in the general population and among those with risk factors such as heavy alcohol intake, obesity, or high fat diets, PFAS increase the risk. These data suggest PFAS exposure and lifestyle risk factors together may increase effects on liver steatosis. 

Exposure to serum perfluoroalkyl substances and biomarkers of liver function: The Korean national environmental health survey 2015-2017

Study Purpose: Exposure to PFAS may increase the risk of liver disease by disrupting cholesterol and lipid metabolism, leading to higher liver-enzyme levels. This study examines the association between exposure to both individual and combined PFAS chemicals and liver-function markers and assesses whether this relationship varies by sex and obesity status.

Study Conclusion: Exposure to individual and combined PFAS chemicals is associated with higher liver enzymes in Korean adults.

Association between perfluoroalkyl substances exposure and the prevalence of nonalcoholic fatty liver disease in the different sexes: a study from the National Health and Nutrition Examination Survey 2005-2018

Study Purpose: There is evidence that PFAS may be toxic to the liver, and there may be differences in this association between sexes. This study aims to explore the association between exposure to PFOA, PFOS, PFHxS, and PFNA and the risk of nonalcoholic fatty liver disease in adults 20 years or older in the US.

Study Conclusion: This study found that PFAS were associated with non-alcoholic fatty liver disease. The associations were different between sexes, even in premenopausal women and postmenopausal women. The association between PFAS exposure and non-alcohol fatty liver disease in women was positive, particularly for PFOA and PFNA. 

Human Evidence of Perfluorooctanoic Acid (PFOA) Exposure on Hepatic Disease: A Systematic Review and Meta-Analysis

Study Purpose: Although many studies have reported an association between PFOA exposure and the risk of developing liver diseases, it is still in debate because studies have shown conflicting results. Therefore, this study reviews literature on the relationship between PFOA exposure and hepatic diseases. 

Study Conclusion: Since the number of studies in this analysis was not large enough to conclude that PFOA exposure is associated with the development of liver diseases, more studies are needed to confirm long-term effects.

Individual and mixture associations of perfluoroalkyl substances on liver function biomarkers in the Canadian Health Measures Survey

Study Purpose: PFAS can disrupt liver metabolism and may be associated with liver function biomarkers. This study examined individual and mixture associations of PFAS on liver function biomarkers in a sample of Canadian adults. They explored how these relationships may change by sex and body mass index (BMI), as well as by physical activity level.

Study Conclusion: Higher plasma concentrations of PFOA, PFOS, PFHxS, and PFNA were associated with higher serum concentrations of liver function biomarkers. The results suggest that higher levels of physical activity appear to protect against the liver toxicity of PFOA. 

Association of Prenatal Exposure to Endocrine-Disrupting Chemicals With Liver Injury in Children

Study Purpose: Prenatal exposure to endocrine disrupting chemicals (EDCs), such as PFAS, may increase the risk for liver injury in children; however, human evidence is scarce. The association between prenatal EDC exposure and hepatocellular apoptosis in children have has not been studied previously

Study Conclusion: This study provides evidence that prenatal exposure to EDCs are associated with higher risk for liver injury and CK-18 levels and constitute a potential risk factor for pediatric nonalcoholic fatty liver disease.

Exposure to per- and Polyfluoroalkyl Substances and Markers of Liver Injury: A Systematic Review and Meta-Analysis

Study Purpose: Experiments have indicated that exposure to certain pollutants is associated with liver damage. The objective of this study was to review literature evaluating PFAS exposure and evidence of liver injury from rodent and epidemiological studies. 

Study Conclusion: There is consistent evidence for PFAS being toxic to the liver in rodent studies, and this is supported by associations of PFAS and markers of liver function in observational human studies.

Per- and perfluoroalkyl substances alternatives, mixtures and liver function in adults: A community-based population study in China

Study Purpose: Evidence from animal studies has shown that PFAS alternatives and mixtures may exert toxic liver effects in animals. However, we have very little evidence in humans. 

Study Conclusion: In conclusion, our study found adverse associations of PFAS alternatives and mixtures with liver function in a Chinese adult general population. Our findings add epidemiological evidence for the potential subclinical hepatotoxicity of PFAS. More studies are needed to confirm our findings and address potential toxicological mechanisms.

Exposure to environmental contaminants is associated with altered hepatic lipid metabolism in non-alcoholic fatty liver disease

Study Purpose: This study tests the hypothesis that exposure to environmental contaminants contributes to the initiation and pathology of non-alcoholic fatty liver disease (NAFLD).

Study Conclusion: Females may be more sensitive to the harmful impacts of PFAS. Lipid-related changes following PFAS exposure may be secondary to the interplay between PFAS and bile acid metabolism.

Prenatal Exposure to Perfluoroalkyl Substances Associated with Increased Susceptibility to Liver Injury in Children

Study Purpose: Non-alcoholic fatty liver disease (NAFLD) is increasing among children. It is important to find risk factors for liver injury that can be addresses through prevention methods.

Study Conclusion: The study observed that higher exposure to PFAS during pregnancy was associated with higher liver enzyme levels in children.

Per- and Polyfluoroalkyl Substances and Obesity, Type 2 Diabetes and Non-alcoholic Fatty Liver Disease: A Review of Epidemiologic Findings

Study Purpose: This study reviews evidence for associations between PFASs and the development of obesity, diabetes, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis.

Study Conclusion: There is evidence that supports the association between PFASs and the onset or development of metabolic diseases, including obesity, diabetes, and non-alcoholic fatty liver disease. However, there are inconsistent results in many cases.

Perfluoroalkyl substances and severity of nonalcoholic fatty liver in Children: An untargeted metabolomics approach

Study Purpose: There have been studies looking at the correlation between PFAS exposure and fatty liver disease in adults and rodents, but there are few studies looking at this correlation in children.

Study Conclusion: PFAS exposure was associated with increased risk of nonalcoholic steatohepatitis (NASH) and fibrosis in children diagnosed with non-alcoholic fatty liver disease (NAFLD).

Sex differences in the association between perfluoroalkyl acids and liver function in US adolescents: Analyses of NHANES 2013-2016

Study Purpose: This study was designed to determine whether or not there is association between exposure to PFASs and signs of liver function in adolescents, and whether or not this varies between sexes.

Study Conclusion: This study was found to have sex differences in the association between PFAS levels and signs of liver function.

Selective Associations of Recent Low Concentrations of Perfluoroalkyl Substances with Liver Function Biomarkers: NHANES 2011 to 2014 Data on US Adults Aged ≥20 Years

Study Purpose: This study looks at the association between PFAS levels and liver function signs.

Study Conclusion: Lower levels of PFOA, PFHxS, and PFNA are associated with higher liver functions, but this association is only seen in obese patients.

Liver function biomarkers disorder is associated with exposure to perfluoroalkyl acids in adults: Isomers of C8 Health Project in China

Study Purpose: This study looks at the association between PFAS levels and liver function signs.

Study Conclusion: These results support previous studies showing association between PFAS exposure and liver function biomarkers.

Environmental perfluoroalkyl acid exposures are associated with liver disease characterized by apoptosis and altered serum adipocytokines

Study Purpose: This study looks at the association between environmental PFASs and signs of liver disease.

Study Conclusion: These findings support previous findings that PFASs may cause liver injury.

Changes in markers of liver function in relation to changes in perfluoroalkyl substances - A longitudinal study

Study Purpose: This study looks at the association of PFAS levels and signs of liver function.

Study Conclusion: These findings suggest a relationship between low-dose PFAS exposure and altered liver function.

 

Metabolic and Digestive System

 

Hypertension

The Hypertension section includes information on blood pressure/hypertension as it relates to PFASs. This section has 14 total studies; 13 are published within the last 6 years. Although a study may find, or not find, an association between PFASs and hypertension outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Hypertension

Plasma levels of per- and polyfluoroalkyl substances (PFAS) and cardiovascular disease – Results from two independent population-based cohorts and a meta-analysis

Study Purpose:  The primary aim of the present study was to investigate incident CVD risk (a combined CVD end-point consisting of myocardial infarction, 
ischemic stroke, or heart failure) in relation to moderately elevated 
levels of PFAS in two population-based cohorts of middle-aged and 
elderly women and men (The Epihealth study and PIVUS study, Uppsala, 
Sweden). In the PIVUS study we also performed a supportive analysis of 
associations between levels of six PFAS and subclinical markers of CVD. 
Meta-analysis was performed together with data from previously 
published studies investigating associations between PFAS levels and 
incident CVD. 

Study Conclusion: This longitudinal study using data from two population-based cohort studies in Sweden did not indicate any increased risk of incident CVD for moderately elevated PFAS levels. A meta-analysis of five independent cohort studies rather indicated a modest inverse association between PFOA levels and incident CVD, further supporting that increasing PFAS levels are not linked to an increased risk of CVD.

 

Perfluoroalkyl substances in umbilical cord blood and blood pressure in offspring: a prospective cohort

Study Purpose: To investigate the potential association between PFAS levels in umbilical cord blood and BP of the offspring at 4 years of age in a prospective cohort study.

Study Conclusion: Our findings suggested that umbilical blood PFAS exposure was negatively associated with BP in offspring at 4 years of age, including SBP, DBP, and MAP.

Prenatal and Childhood Per- and Polyfluoroalkyl Substance (PFAS) Exposures and Blood Pressure Trajectories From Birth to Late Adolescence in a Prospective US Prebirth Cohort

Study Purpose: This study investigates associations with prenatal PFAS exposure and blood pressure in children.

Study Conclusion: There were associations between prenatal and childhood PFAS exposure with blood pressure at specific time points between birth and late teenage years, but it was not consistent over time.

Association between per- and polyfluoroalkyl substances and risk of hypertension: a systematic review and meta-analysis

Study Purpose: Evidence suggests exposure to PFAS may increase risk of hypertension, but findings are inconsistent. This study summarizes the relationship between FPAS and hypertension.

Study Conclusion: This study evaluated the link between PFAS exposure and hypertension, finding that higher levels of PFOS, PFOA, and PFHxS were correlated with increased risk of hypertension. 

The relationship between perfluoroalkyl substances and hypertension: A systematic review and meta-analysis

Study Purpose: Hypertension is an important risk factor for cardiovascular diseases. This study evaluates the body of evidence from past studies on the correlation between PFAS exposure and hypertension.

Study Conclusion: This study observed that PFAS exposure is a risk factor for hypertension, but that there are differences in this relationship between men and women. Males exposed to PFNA, PFOA, and PFOS appeared to have a higher risk of hypertension compared to females. Further study is needed to understand the underlying mechanism causing this relationship.

The role of exposure to per- and polyfluoroalkyl substances in racial/ethnic disparities in hypertension: Results from the study of Women's health across the nation

Study Purpose: Racial/ethnic disparities in hypertension are a pressing public health problem. The contribution of environmental pollutants such as PFAS have not been explores, even though certain PFAS have been thought to be higher in Black populations and have been associated with hypertension. This study examines the extent to which racial/ethnic disparities in hypertension are explained by racial/ethnic differences in serum PFAS levels.

Study Conclusion: These findings suggest differences in PFAS exposure may be an unrecognized modifiable risk factor that partially accounts for racial/ethnic disparities in timing of hypertension onset among midlife women.

Per- and Polyfluoroalkyl Substances and Incident Hypertension in Multi-Racial/Ethnic Women: The Study of Women's Health Across the Nation

Study Purpose: PFAS may disrupt blood pressure controls; however, human evidence to support this hypothesis is lacking. This study examines the association between serum PFAS and risk of developing hypertension.

Study Conclusion: Several PFAS showed positive associations with hypertension. These findings suggest that PFAS may contribute to women's cardiovascular disease risk.

Associations of serum PFOA and PFOS levels with incident hypertension risk and change of blood pressure levels

Study Purpose: This study aimed to evaluate the associations of PFOA and PFOS levels with hypertension risk and change of blood pressure levels over 5 years.

Study Conclusion: In conclusion, the present study found a negative association of serum PFOS levels with the incident hypertension risk and the magnitude of systolic blood pressure rise. Further researches are warranted to verify our findings and to explore the potential mechanisms behind this association.

Exposure to toxic metals and per- and polyfluoroalkyl substances (PFAS) and the risk of preeclampsia and preterm birth in the United States: A review

Study Purpose: This article reviews past studies to provide an overview on environmental contaminants (such as PFAS) and the development of preeclampsia and preterm birth among U.S. women.

Study Conclusion: There are inconsistent findings on the relationship between PFASs and preeclampsia and preterm birth.

Per- and Polyfluoroalkyl Substance and Cardio Metabolic Markers in Firefighters

Study Purpose: This study aims to evaluate if PFAS are associated with cardio metabolic markers.

Study Conclusion: PFHxS levels were elevated in firefighters compared to the general population. PFAS levels were not associated with increased cardiometabolic risk measures in this population of firefighters.

Perfluoroalkyl substances are associated with elevated blood pressure and hypertension in highly exposed young adults

Study Purpose: Residents in a large area of North-Eastern Italy were exposed to PFAS via drinking water. Studies on the association between PFAS and blood pressure levels have found inconsistent results. This study looks at the association between PFAS levels and blood pressure and hypertension.

Study Conclusion: These results suggest that PFAS levels are associated with increased blood pressure in highly exposed adults.

Serum levels of per- and polyfluoroalkyl substances alternatives and blood pressure by sex status: Isomers of C8 health project in China

Study Purpose: This study looks at the associations between PFAS levels and blood pressure.

Study Conclusion: In this study, levels of PFASs are associated with higher blood pressure. Women appeared to be more susceptible than men.           

Association between perfluoroalkyl acids and the prevalence of hypertension among US adults

Study Purpose: This study looks at the association of PFAS levels with hypertension and blood pressure in adults

Study Conclusion: PFOA and PFHxS were related with higher risk of hypertension at lower levels and higher levels.

Association between perfluoroalkyl substance concentrations and blood pressure in adolescents

Study Purpose: This study looks at the associations between PFAS levels and hypertension in adolescents.        

Study Conclusion: These results provide evidence that PFOS level increases are associated with increases in diastolic blood pressure.

Gender-specific associations between serum isomers of perfluoroalkyl substances and blood pressure among Chinese: Isomers of C8 Health Project in China

Study Purpose: This study looks at the relationship between a variety of PFAS types and blood pressure.

Study Conclusion: PFASs were associated with elevated blood pressure.

 

Lipids and Obesity

The Lipids and Obesity section includes information on metabolic syndrome, lipids (total cholesterol, triglycerides, HDL, LDL), dyslipidemia, lipoprotein and apolipoprotein, and obesity (including BMI, bariatric surgery, and weight loss) as they relate to PFASs. Lipoprotein and apolipoprotein carry lipids through the body. This section includes 98 total studies; 88 were published in the last 6 years. Although a study may find, or not find, an association between PFASs and lipid/obesity outcomes, this does not mean it is, or is not, definitively a causative agent. Findings in studies are not necessarily generalizable among all sexes, ethnicities/races, smokers/non-smokers, and geographic areas; this should be considered when interpreting these results. Differences in findings between studies could be due to the population studied (demographics, geography, diet, etc.), size of the studies, differences in PFAS concentrations between studies, when samples were taken, or other factors.

 

Obesity, body fat, and weight loss

 

Association of per‑ and polyfuoroalkyl substance exposure with metabolic syndrome and its components in adults and adolescents

Study Purpose: The aim was to explore the potential mechanisms through which PFAS might infuence MetS and to lay the groundwork for future research.

Study Conclusion: Our study found that PFAS was associated with a lower prevalence of MetS in both adults and adolescents, offering new insights into the relationship between PFAS and metabolic health. Interestingly, however, we observed conflicting findings across the components of MetS.

Prenatal exposures to mixtures of endocrine disrupting chemicals and sex-specific associations with children's BMI and overweight at 5.5 years of age in the SELMA study

Study Purpose: Prenatal exposure to endocrine disrupting chemicals (EDCs) such as PFAS may disrupt human metabolism. Prenatal exposure to EDCs such as PFAS have been inconsistently associated with BMI and obesity in children. This study investigated if prenatal exposure to many EDCs was associated with children's BMI and overweight at 5 years of age.

Study Conclusion: Prenatal exposure to EDCs in this study was associated with BMI and overweight in 5 year old children, with differences between boys and girl. The levels of EDCs were associated with lower BMI and lower risk of overweight among girls. 

Prenatal and childhood exposure to per-/polyfluoroalkyl substances (PFASs) and its associations with childhood overweight and/or obesity: a systematic review with meta-analyses

Study Purpose: This work reviews past studies to summarize the associations between prenatal or childhood exposure to PFASs and childhood overweight/obesity.

Study Conclusion: There is evidence to suggest possible associations between prenatal PFAS exposure and childhood BMI, and stronger evidence that suggests childhood exposure to PFAS is associated with lower childhood BMI.

Per- and polyfluoroalkyl substances, gestational weight gain, postpartum weight retention and body composition in the UPSIDE cohort

Study Purpose: This study investigates PFAS exposure and associations with gestational weight gain and postpartum body mass index.

Study Conclusion: PFAS, particularly PFOA and PFHxS, were associated with altered patterns of gestational weight gain and postpartum BMI.

Associations of Gestational Perfluoroalkyl Substances Exposure with Early Childhood BMI z-Scores and Risk of Overweight/Obesity: Results from the ECHO Cohorts

Study Purpose: Gestational PFAS exposure may be associated with increased body fatness and increased risk of obesity among children and adolescents. However, studies in humans have had inconsistent findings. This study estimates the associations of pregnancy PFAS concentrations with child body mass index and risk of overweight/obesity in the U.S.

Study Conclusion: Gestational exposure to higher levels of PFAS were associated with slightly higher child BMIs and risk of overweight or obesity.

Weight loss relapse associated with exposure to perfluoroalkylate substances

Study Purpose: The purpose of this study was to test the hypothesis that PFAS exposures are associated with body weight increases.

Study Conclusion: In this study of Europeans with obesity, elevated plasma PFAS concentrations predicted increased weight gain after an initial weight loss, no matter the diet group that the participants were assigned to. The results suggest that PFOA and PFHxS may cause weight gain among people with obesity in weight loss programs.

Nutritional Modulation of Associations between Prenatal Exposure to Persistent Organic Pollutants and Childhood Obesity: A Prospective Cohort Study

Study Purpose: Prenatal exposure to environmental chemicals such as PFAS may contribute to the development of childhood obesity and metabolic disorders. However, it is not known whether maternal nutrition status during pregnancy affects this relationship. This study aimed to assess the associations between prenatal levels of environmental chemicals and maternal nutritional status on childhood obesity.

Study Conclusion: These results support that maternal nutritional status may affect the relationship between prenatal exposure to environmental chemicals such as PFAS and childhood overweight/obesity.

Maternal per- and poly-fluoroalkyl substances exposure and child adiposity measures: A birth cohort study

Study Purpose: Maternal exposure to PFAS during pregnancy may affect physical development of offspring. This study evaluates associations between maternal PFAS exposure and offspring body fatness during the first two years of life.

Study Conclusion: In this study, they found that maternal PFAS exposure may increase body fatness in young children. This relationship may vary by specific PFAS chemical.

In utero exposure to perfluoroalkyl substances and early childhood BMI trajectories: A mediation analysis with neonatal metabolic profiles

Study Purpose: In utero PFAS exposure has been associated with childhood body weight, but the mechanisms are not well understood. This study investigates the potential mediating role of neonatal metabolites in the relationship between prenatal PFAS exposure and childhood body weight trajectories in the first four years of life.

Study Conclusion: Prenatal exposure to PFAS was associated with a persistent increase in BMI trajectory in early childhood. This relationship may be partially affected by acylcartinine C8, a fatty acid, suggesting a role of perturbed fatty acid metabolism in the pathway between PFAS and BMI.

Cross-sectional associations between exposure to per- and polyfluoroalkyl substances and body mass index among European teenagers in the HBM4EU aligned studies

Study Purpose: PFAS are widespread that may impact youth body mass index (BMI). This study investigated associations between PFAS and BMI in teenagers across nine European countries.

Study Conclusion: There was evidence of negative cross-sectional associations with age- and sex- standardized BMI for 5 of the 10 PFAS compounds in teenagers from nine studies across Europe. This indicates that these exposures may impact pathways relevant to metabolism in teenagers. Our results furthermore suggest opposite associations for PFOS, PFOA and PFNA versus PFHxS on BMI z-scores in teenagers. Although effect estimates were only minor, this could still be relevant for population health considering that such a large part of the population is exposed to these compounds. Further research is needed.

Prenatal exposure to per- and polyfluoroalkyl substances and childhood adiposity at 7 years of age

Study Purpose: An increasing number of studies have reported that prenatal PFAS exposure may increase childhood adiposity. However, limited data is available in China and the overall effects of PFAS mixtures remain unclear. The goal of this study was to examine the association of prenatal exposure to individual PFAS and PFAS mixtures with childhood adiposity at 7 years of age.

Study Conclusion: This study suggests potential sex-specific associations of prenatal exposure to individual PFAS and their mixture with childhood adiposity, with the observed relationship being negative for boys but positive for girls.

Serum levels of perfluoroalkyl substances (PFAS) and body composition - A cross-sectional study in a middle-aged population

Study Purpose: It has been suggested that PFAS are endocrine disruptors with a potential to influence fat mass.

Study Conclusion: PFOS and PFHxS levels did not show any consistent associations with body composition, but PFOA, PFNA, and PFDA were inversely related to multiple measures reflecting the amount of fat, but in women only.

Prenatal exposure to persistent organic pollutants and childhood obesity: A systematic review and meta-analysis of human studies

Study Purpose: This paper presents a review of existing literature on the association between prenatal exposure to persistent organic pollutants (POPs), such as PFAS, and childhood obesity.

Study Conclusion: The current evidence from epidemiological studies suggests that prenatal exposures to DDE and HCB are associated with greater body fatness in childhood. There was insufficient evidence to conclude that prenatal exposure to other POPs, including PFAS, are associated with obesity in children. 

Umbilical cord serum concentrations of perfluorooctane sulfonate, perfluorooctanoic acid, and the body mass index changes from birth to 5 1/2 years of age

Study Purpose: This study investigates whether umbilical cord blood concentrations of PFOS and PFOA are associated with children's risk trajectory for obesity.

Study Conclusion: These findings demonstrate that the effect of prenatal exposure to PFAS is a possible risk for obesity through an increase in BMI, especially for girls.

Temporal trends of concentrations of per- and polyfluoroalkyl substances among adults with overweight and obesity in the United States: Results from the Diabetes Prevention Program and NHANES

Study Purpose: This study aims to determine trends and rate of change of plasma PFAs concentrations in overweight or obese U.S. adults and evaluate if this changes by sex, race/ethnicity, or age.

Study Conclusion: They observed a decreasing trend in plasma PFOS in overweight/obese participants over time. Male and Black participants showed higher PFOS and PFNA than female and white participants.

Associations between exposure to perfluoroalkyl substances and body fat evaluated by DXA and MRI in 109 adolescent boys

Study Purpose: Exposure to PFASs has been associated with changes in BMI and adiposity, but evidence is inconsistent between studies. This study investigates the associations between PFAS exposure and body fat in a cross-sectional study of healthy boys.

Study Conclusion: Overall, we found no consistent associations between PFAS exposure and body fat. This could be due to our cross-sectional study design. Furthermore, we assessed PFAS exposure in adolescence and not in utero, which is considered a more vulnerable time window of exposure.

Perfluoroalkyl and polyfluoroalkyl substances and body size and composition trajectories in midlife women: the study of women's health across the nation 1999-2018

Study Purpose: This study examined associations of serum PFAS concentrations with trajectories of weight, waist circumference, fat mass, and proportion of fat in midlife women.

Study Conclusion: Certain PFAS were positively associated with greater body size and body fat, and higher rates of change over time. PFAS may be a contributing factor to obesity risk.

Plasma Concentrations of Per- and Polyfluoroalkyl Substances and Body Composition from Mid-childhood to Early Adolescence

Study Purpose: This study evaluates the associations of PFAS levels in childhood with body changes through early adolescence.

Study Conclusion: In a large prospective U.S. cohort, children with higher plasma concentrations of PFAS had less accrual of lean mass from mid-childhood to early adolescence. While children with higher plasma concentrations of some PFAS (i.e., PFOS and PFHxS) had less accrual of fat mass, particularly subcutaneous fat mass, children with higher concentrations of other PFAS (i.e., PFDA and PFNA) had greater accrual of visceral fat mass. Thus, early life exposure to some but not all PFAS may be associated with adverse changes in body composition.

Exposure to perfluoroalkyl substances (PFAS) and dyslipidemia, hypertension and obesity in adolescents. The Fit Futures study

Study Purpose: The prevalence of obesity, hypertension, and dyslipidemia has been increasing in children and teenagers across the world. Exposure to environmental pollutants may contribute to this. The aim of this study was to look at the associations between PFASs and dyslipidemia, hypertension, and obesity in a sample of adolescents

Study Conclusion: This study showed a possible link between several PFASs and dyslipidemia, hypertension, and obesity in this adolescent sample.

The Confounder-Mediator Dilemma: Should We Control for Obesity to Estimate the Effect of Perfluoroalkyl Substances on Health Outcomes?

Study Purpose: This article describes possible biases that can be introduced by adjusting for obesity in PFAS studies.

Study Conclusion: This article highlights the complexity of seemingly simple adjustment or stratification analyses, and the need for careful consideration of the confounding and/or mediating role of obesity in PFAS studies.

Exposure to Per- and Polyfluoroalkyl Substances and Adiposity at Age 12 Years: Evaluating Periods of Susceptibility

Study Purpose: PFAS exposure may increase body fatness and obesity risk in children. This study estimates associations of PFAS concentrations with adolescent risk of overweight/obesity.

Study Conclusion: There were positive associations between gestational PFOA and PFHxS levels with stomach fat levels and the risk of obesity in adolescents, while no pattern was seen for postnatal PFAS concentrations.

Gestational perfluoroalkyl substance exposure and body mass index trajectories over the first 12 years of life

Study Purpose: Gestational exposure to PFAS is associated with increased risk of obesity and cardiometabolic disease. This study explores that association.

Study Conclusion: These results suggest that gestational PFOA exposure may be associated with BMIs related to adult obesity and cardiometabolic disease, while PFOS and PFHxS exposure is associated with lower BMI in the first 12 years of life.

PFAS exposure and overweight/obesity among children in a nationally representative sample

Study Purpose: PFASs are associated with cardiovascular disease, but their relationship with obesity, a risk factor for cardiovascular disease, is not known. This study explores the relationship between PFAS and overweight/obesity and abdominal obesity in children.

Study Conclusion: Findings show that there may be an associated between elevated PFOA and overweight/obesity among children.

Prenatal Exposures to Perfluoroalkyl Acids and Associations with Markers of Adiposity and Plasma Lipids in Infancy: An Odense Child Cohort Study

Study Purpose: Maternal PFAS concentrations have been associated with offspring obesity and dyslipidemia (abnormal levels of cholesterol and other lipids) in childhood and adulthood, but this association has not been studied in infancy. This study looks as the associations between maternal PFAS concentrations and signs of obesity and lipid metabolism in infancy.

Study Conclusion: Prenatal PFAS levels were associated with greater signs of obesity and higher total cholesterol in infancy.

Per- and Polyfluoroalkyl Substances and Obesity, Type 2 Diabetes and Non-alcoholic Fatty Liver Disease: A Review of Epidemiologic Findings

Study Purpose: This study reviews evidence for associations between PFASs and the development of obesity, diabetes, and non-alcoholic fatty liver disease/non-alcoholic steatohepatitis.

Study Conclusion: There is evidence that supports the association between PFASs and the onset or development of metabolic diseases, including obesity, diabetes, and non-alcoholic fatty liver disease. However, there are inconsistent results in many cases.

Isomers of perfluoroalkyl substances and overweight status among Chinese by sex status: Isomers of C8 Health Project in China

Study Purpose: Studies on the associations of PFASs with overweight/obesity have mixed results. This study examines the relationship between BMI, waist circumference, and overweight and PFASs.

Study Conclusion: This study suggests that PFASs are associated with overweight or increased waist circumference, and these associations are stronger in women. PFOA had the strongest association.

Decreased plasma levels of perfluoroalkylated substances one year after bariatric surgery

Study Purpose: This study determines the levels of PFASs before and after bariatric surgery, and to assess whether weight loss and protein levels could influence one another.

Study Conclusion: Bariatric surgery did not influence the changes of PFAS levels before and after the operation.

Prenatal exposure to persistent organic pollutants and child overweight/obesity at 5-year follow-up: a prospective cohort study

Study Purpose: Prenatal exposure to some pollutants, such as PFASs, may influence offspring weight gain. This study looks at the relationship between prenatal exposure to PFASs and child overweight/obesity.

Study Conclusion: Increasing PFAS levels were associated with greater risk of child overweight/obesity at 5 years.

Perfluoroalkyl Substances during Pregnancy and Offspring Weight and Adiposity at Birth: Examining Mediation by Maternal Fasting Glucose in the Healthy Start Study

Study Purpose: Prenatal PFAS exposure has been associated with lower birth weight; however, impacts on body weight in later life is not well known. This study looks at the associations between maternal PFAS concentrations and offspring weight and percent body fat at birth, as well as to estimate associations between PFAS concentrations and maternal blood glucose and lipid levels.

Study Conclusion: Prenatal exposure to some PFASs was associated with lower birthweight and percent body fat at birth.

Prenatal Exposure to Perfluoroalkyl Substances and Body Fatness in Girls

Study Purpose: This study looks at the association between exposure to PFAS during pregnancy and female children's percent body fat at age 9.

Study Conclusion: Prenatal exposure to PFOA and PFOS was associated with girls' percent body fat.

Early-life exposures to persistent organic pollutants in relation to overweight in preschool children

Study Purpose: Some pollutants, such as PFASs, are suspected to be related to causing obesity. This study looks at the associations of maternal and child levels of PFASs with the risk of childhood overweight.

Study Conclusion: In this study, there were associations between maternal PFOS and PFOA levels and overweight risk in preschool children.

Prenatal Exposure to Perfluoroalkyl Substances and Adiposity in Early and Mid-Childhood

Study Purpose: This study looks at the associations of prenatal exposure to PFASs with obesity in early and mid-childhood.

Study Conclusion: Prenatal exposure to PFASs was associated with small increases in weight measurements in mid-childhood, but only among girls.

Lipids: cholesterol and triglycerides

Per- and Polyfluoroalkyl Substances (PFAS) and Lipid Trajectories in Women 45-56 Years of Age: The Study of Women's Health Across the Nation

Study Purpose: This study looks at associations between serum PFAS levels and levels of blood total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides in middle-aged women undergoing menopause.

Study Conclusion: This study showed that PFAS concentrations were associated with less-favorable cholesterol levels, particularly total and LDL cholesterol. This suggests that PFAS exposure may be a risk factor for cholesterol disorders.

Associations between Per- and Polyfluoroalkyl Substances Exposures and Blood Lipid Levels among Adults-A Meta-Analysis

Study Purpose: This study aims to summarize associations between PFAS and blood lipid levels in adults.

Study Conclusion: These results suggest that plasma PFAS levels are associated with cholesterol in small HDL, IDL, and all LDL subfractions, as well as apolipoproteins and composite fatty acid and phospholipid profiles but to a lesser extent with triglycerides in lipoproteins. 

Associations of perfluoroalkyl substances (PFAS) with lipid and lipoprotein profiles

Study Purpose: Recent studies suggest that PFAS are involved in cholesterol metabolism, but the mechanisms underlying the associations are poorly understood. This study aims to evaluate associations of plasma PFAS with lipids in adults.

Study Conclusion: These results suggest that plasma PFAS levels are associated with cholesterol in small HDL, IDL, and all LDL subfractions, as well as apolipoproteins and composite fatty acid and phospholipid profiles but to a lesser extent with triglycerides in lipoproteins. 

Occurrence of legacy and alternative per- and polyfluoroalkyl substances in serum from high exposure population and their disrupting effects on serum lipids and thyroid function

Study Purpose: High exposure to PFAS has been reported in chemical production areas in China, but human studies on exposure risk is still limited. In this study, 26 PFAS chemicals were measured in the blood of adults living in a famous chemical production area in northern China. The effects of this PFAS exposure on lipid levels and thyroid function were explored. 

Study Conclusion: In this study, concentrations of PFAS were detected in serum samples of 161 adults. A high level of PFOA was observed in serum samples, which contributed 72 % of the total PFAS concentrations. The serum PFOA of all participants was higher than the US EPA derived reference dose for increased total cholesterol, and higher serum PFOA was associated with increased total cholesterol and LDL in serum. No significant association was observed between PFAS and thyroid stimulating hormone (TSH) levels or any other autoimmunity markers. Compared to effects of individual PFAS, co-exposure of long-chain PFAS including n-PFOA, PFNA, PFDA, and PFOS showed effects on free T4, while the mixture of serum PFBA and 6:2Cl-PFESA showed a influence on total and free T3 levels. It revealed that both legacy and alternative PFAS could interrupt thyroid function, but the effects and related mechanisms may be different. 

Plasma concentrations of per- and polyfluoroalkyl substances are associated with perturbations in lipid and amino acid metabolism

Study Purpose: Little is known about how PFAS impact underlying biology that leads to adverse health effects. The metabolome represents the end results of cellular processes and has been used in the past to understand changes in the body that lead to disease. This study investigates whether exposure to PFAS was associated with the metabolome. 

Study Conclusion: This study represents an investigation into the metabolomic profiles of mothers and children in response to PFAS exposure. Our results indicated disrupted metabolism of both lipids and amino acids, and specifically showed Sphingomyelins, Lysophospholipid, Long Chain Polyunsaturated Fatty Acid (n3 and n6), Fatty Acid- Dicarboxylate, and Urea cycle metabolism as particular pathways of interest that may play a large role in adverse health effects related to PFAS exposures. These findings may vary by age and sex. 

Metabolome-wide association study of four groups of persistent organic pollutants and abnormal blood lipids

Study Purpose: Research has shown that persistent organic pollutants, such as PFAS, are associated with a higher risk of abnormal blood lipid levels in humans, which this study aims to investigate.

Study Conclusion: This study found that blood PFAS levels were associated with total cholesterol and LDL levels and that certain factors may affect these associations. The PPARγ mechanism likely plays a role in the relationships between PFHxS, PFNA, PFOS, and abnormal cholesterol metabolism.

Serum per- and polyfluoroalkyl substances and abnormal lipid metabolism: A nationally representative cross-sectional study

Study Purpose: The associations of legacy PFAS with lipid metabolism are controversial, and there is little information about the impact of emerging PFAS on lipid metabolism. This study aimed to explore the associations of legacy and emerging PFAS with lipid profiles and dyslipidemia in Chinese adults.

Study Conclusion: This study showed that lipid levels and dyslipidemia may be associationed with PFAS exposure in the Chinese population, with PFHpS, PFUnDA, PFNA, and PFOS having the strongest associations. 6:2 Cl-PFESA also had a positive association with lipid profiles, but the effect was smaller than that of PFOS, which may be related to the different durations of exposure to legacy and emerging PFAS. The dose–response relationship between PFAS and lipid profiles was nonlinear. More studies should be conducted in the future to verify these findings and investigate the potential biological mechanisms.

Effect of lifestyle-based lipid lowering interventions on the relationship between circulating levels of per-and polyfluoroalkyl substances and serum cholesterol

Study Purpose: Exposure to certain PFAS has been shown to be positively associated with total and/or LDL cholesterol. Examining this association in cholesterol-lowering interventions may provide additional evidence linking PFAS to cardiovascular risk. This study examines the relationship of 6 PFAS with cholesterol in a 6-month lifestyle-based intervention.

Study Conclusion: The levels of PFAS observed, except for PFOS, were comparable to national levels. This cohort had clinically significant cholesterol levels at baseline, and the cohort shows similarities to the average US adult. The results indicate that lipid-lowering through lifestyle modification may impact levels of PFAS in the body.

Perfluoroalkyl Substance Serum Concentrations and Cholesterol Absorption-Inhibiting Medication Ezetimibe

Study Purpose: PFAS have been associated with multiple health effects, including higher serum cholesterol and LDL cholesterol. This study investigates potential population differences in serum PFAS attributable to exetimibe, a medication that inhibits cholesterol absorption. 

Study Conclusion: Ezetimibe does not appear to affect serum PFAS concentrations. We sought but did not find direct evidence that ezetimibe could inhibit PFAS uptake nor inferential evidence that inter-individual differences in sterol absorption could provide a confounding factor explanation for the association of serum total- and LDL-cholesterol with serum PFAS.

Is the cholesterol-perfluoroalkyl substance association confounded by dietary fiber intake?: a Bayesian analysis of NHANES data with adjustment for measurement error in fiber intake

Study Purpose: Concentrations of total cholesterol and other lipid measures have been associated with PFAS in humans, even among those with only background-level exposure to PFAS. Fiber is known to decrease cholesterol and recent reports showed that PFAS and fiber intake may be inversely associated. This study investigates the notion that confounding by dietary fiber may account for some of the association between cholesterol and PFAS.

Study Conclusion: The results indicated that the association of serum cholesterol with PFAS was not substantially confounded by fiber intake.

Associations of PFAS-related plasma metabolites with cholesterol and triglyceride concentrations

Study Purpose: To better understand the PFAS-induced effects on lipid pathways, this study investigated associations between PFAS exposure and cholesterol and triglyceride concentrations.

Study Conclusion: In conclusion, this study did not find evidence for associations of PFAS with total cholesterol. Instead, they found that PFAS exposure was associated with triglyceride levels.

Associations between Mixture of Perfluoroalkyl Substances and Lipid Profile in a Highly Exposed Adult Community in the Veneto Region

Study Purpose: Residents of the Veneto region in Northern Italy were exposed to drinking water contaminated by PFAS for decades. While exposure to PFAS has been consistently associated with elevated serum lipids, combined exposures to multiple PFASs have been poorly investigated. Utilizing different statistical approaches, we examine the association between chemical mixtures and lipid parameters.

Study Conclusion: In this study, we found that PFAS exposure, especially PFOS and PFNA, is associated with lipid levels in this population. The mixture of PFOA, PFOS, PFHxS, and PFNA with higher concentrations in blood samples was associated with higher total cholesterol, HDL cholesterol, and LDL cholesterol.

Drinking Water-Associated PFAS and Fluoroethers and Lipid Outcomes in the GenX Exposure Study

Study Purpose: Residents of Wilmington, NC were exposed to drinking water contaminated by PFAS from 1980 to 2017. This study measured the association between serum PFAS levels and cholesterol outcomes.

Study Conclusion: PFNA and PFOS were associated with higher levels of total and non-HDL cholesterol, with associations larger in magnitude among older adults. Fluoroethers appeared to be associated with HDL but non-HDL lipid measures.

Perfluoroalkyl substances and lipid concentrations in the blood: A systematic review of epidemiological studies

Study Purpose: This review assesses PFAS associations with LDL and HDL cholesterols, total cholesterol, and total triglyceride concentrations.

Study Conclusion: There was evidence of associations between the concentrations of some PFAS-lipid pairs in humans. 

Lipoprotein profiles associated with exposure to poly- and perfluoroalkyl substances (PFASs) in the EuroMix human biomonitoring study

Study Purpose: Exposure to PFAS is associated with increased blood cholesterol. Although elevated cholesterol is a well-established risk factor for cardiovascular diseases, it is not clear whether PFAS affect this risk. Lipoproteins may provide an insight to physiological implications of PFAS exposure. This study explores the association between PFAS concentrations and lipoproteins.

Study Conclusion: Background PFAS serum concentrations were associated with altered lipoprotein profiles in a generally healthy population. The strongest associations identified were between long-chained PFCAs and increased cholesterol in large and medium sized HDL-particles in women. The change in cholesterol distribution among the LDL-particles appeared more complex, but the most significant increases were found among the LDL1-LDL3 fraction and in particular among the PFCAs. A general reduction in large VLDL particle number and lipid content was suggested. This study suggests that PFAS serum concentrations are associated with both lipoprotein particle distributions and particle content at background PFAS exposure levels.

Perfluoroalkyl substance mixtures and cardio-metabolic outcomes in highly exposed male workers in the Veneto Region: A mixture-based approach

Study Purpose: PFAS have been consistently associated with cardio-metabolic traits. Occupational exposures to multiple PFAS with health outcomes have been poorly investigated. The aim of the present study was to examine these associations among former workers involved in PFAS production.

Study Conclusion: The results showed a clear association between serum PFAS levels and markers of cardiovascular risk and support the importance of clinical surveillance of cardiovascular risk factors in population with a high exposure to PFAS, especially in the occupational setting.

The association between blood PFAS concentrations and clinical biochemical measures of organ function and metabolism in participants of the Canadian Health Measures Survey (CHMS)

Study Purpose: This study tests the association between human blood levels of PFAS and measures of organ and metabolic function among a nationally representative sample of 6768 participants in Canada.

Study Conclusion: At the concentrations found in a large sample of the Canadian population, we found that selected PFAS were associated with biochemical markers of liver, kidney and thyroid function, and lipid, calcium and glucose metabolism. We also found associations between several PFAS and GGT, a marker of all-cause mortality. The observed associations on average were generally small and need to be interpreted with caution, but they may possibly be important at a population level and in population subgroups, who may have higher than average exposure. More research is needed.

Changes in plasma levels of per- and polyfluoroalkyl substances (PFAS) are associated with changes in plasma lipids - A longitudinal study over 10 years

Study Purpose: Associations between PFAS and increased blood lipids have been reported primarily from cross-sectional studies. The aim of this study was to investigate associations between multiple PFAS and blood lipids.

Study Conclusion: In this study with three measurements over 10 years of both plasma PFAS and lipids, increasing levels of PFAS were associated with changes in plasma lipids.

The effects of Cl-PFESAs exposure on blood lipids – A community-based large population study in Guangzhou

Study Purpose: In this study, they investigate the association between CI-PFESAs, a PFAS alternative in China, and blood lipid profiles in community residents.

Study Conclusion: This study found a positive association between Cl-PFESAs and total cholesterol, triglycerides, and LDL cholesterol, as well as a negative association between Cl-PFESAs and dyslipidemia. An exposure-response relationship was suggested between PFAS alternatives and lipids.

Why is elevation of serum cholesterol associated with exposure to perfluoroalkyl substances (PFAS) in humans? A workshop report on potential mechanisms

Study Purpose: There may be an association between PFAS exposure and elevated cholesterol. A workshop was held in 2019 to discuss possible mechanisms behind this. In this report, they summarize data, discussion among attendees, and recommendations for further research.

Study Conclusion: The mechanisms behind the association of serum cholesterol with exposure to PFAS have not been determined.

Lipid responses to environmental perfluoroalkyl substance exposure in a Taiwanese Child cohort

Study Purpose: The purpose of this study was to assess changes in lipids in children after exposure to PFASs and suggest potential health effects.

Study Conclusion: This study found that some PFASs were associate with lipid changes. The PFOS level was most correlated with lipid alterations. The results of these lipid alterations suggest possible effects on hepatic lipid metabolism, metabolic disorders, and PFAS interactions in the body.

Early-life associations between per- and polyfluoroalkyl substances and serum lipids in a longitudinal birth cohort

Study Purpose: Exposures to PFASs may affect metabolic outcomes, including lipid concentrations in blood. This study estimates associations between PFAS and lipid concentrations at birth and at several points in childhood.

Study Conclusion: These findings suggest that childhood PFAS exposures may be associated with elevated serum lipid concentrations. This is a public health concern because a detrimental lipid profile in childhood is a risk factor for later development of hyperlipidemia and cardiovascular disease.

Systemic PFOS and PFOA exposure and disturbed lipid homeostasis in humans: what do we know and what not?

Study Purpose: This review presents the main issues on regulation of lipids by PFOS and PFOA, emphasizing underlying mechanisms in the body.

Study Conclusion: There is a difference between the mechanisms in lipid regulation in mice versus humans, which may be due to doses of PFASs.

Perfluoroalkyl substances (PFASs) and mercury in never-pregnant women of fertile age: association with fish consumption and unfavorable lipid profile

Study Purpose: This study examines concentrations of PFASs and lifestyle factors that may contribute to higher levels of pollutants in women of fertile age who have never been pregnant.

Study Conclusion: The majority of the women in this study had a mixture of seven different PFASs and mercury detected in their blood. PFAS concentrations were higher in older women and associated with fish intake.

The association between perfluoroalkyl substances and lipid profile in exposed pregnant women in the Veneto region, Italy

Study Purpose: Residents of northeastern Italy were exposed for decades to high concentrations of PFASs via drinking water. Elevated lipid levels during pregnancy can have long-lasting effects on pregnant women and the developing fetus. This study looks at the association between PFASs and lipid levels in highly exposed pregnant women.

Study Conclusion: These results suggest that the associations between PFAS concentrations and lipid levels in pregnant women may differ by trimester of pregnancy. In the first trimester, patterns are like those in non-pregnant women, while they differ in late pregnancy.

Serum perfluoroalkyl substances in relation to lipid metabolism in Chinese pregnant women

Study Purpose: Exposure to PFASs could affect lipid levels, but studies on these effects in pregnant women are limited. This study looks at the association between PFASs and lipid levels in pregnant women.

Study Conclusion: Exposure to PFASs may influence lipid levels in pregnant women.

Associations between perfluoroalkyl substances and lipid profile in a highly exposed young adult population in the Veneto Region

Study Purpose: Residents of a large area of North-Eastern Italy were exposed for decades to drinking water contaminated by PFAS. This study looks at the association between PFAS levels and lipid levels and how the amount of PFAS changes this association in this heavily exposed population.

Study Conclusion: The largest jumps in cholesterol levels occurred at the lower ranges of PFAS concentrations.

Prenatal exposure to perfluoroalkyl substances and cord plasma lipid concentrations

Study Purpose: The effects of PFAS exposure on lipid levels in newborns is unknown. This study looks at the health effects of prenatal exposure to PFAS on umbilical cord lipid levels.

Study Conclusion: These findings suggest that prenatal exposure to PFAS may disrupt lipid levels and metabolism in newborns.

Serum albumin mediates the effect of multiple per- and polyfluoroalkyl substances on serum lipid levels

Study Purpose: Previous studies looking at the association between PFAS exposure and lipid levels have mainly focused on individual PFASs; the influence of multiple PFAS exposure on lipids is not clear. This study looks at the combined effects of multiple PFASs on lipid levels.

Study Conclusion: PFAS exposure was associated with lipid levels.

Associations between perfluoroalkyl substances and serum lipids in a Swedish adult population with contaminated drinking water

Study Purpose: Exposure to PFAS have been shown to affect lipid levels in past studies. This study looks at the association between lipid levels and PFAS, and if these associations with PFAS remained in a comparison based on residency in areas with differing exposure to PFAS.

Study Conclusion: This study provides more evidence of an association between PFAS and lipid levels, especially for PFHxS.

The Association Between Perfluoroalkyl Substances and Lipids in Cord Blood

Study Purpose: PFAS were suspected to have been released during the collapse of the World Trade Center on 9/11. Evidence suggests that PFAS may alter lipid levels. This study looks at the association between umbilical cord PFAS levels and lipids in a group prenatally exposed to the WTC disaster.

Study Conclusion: These findings support an association between exposure to PFAS and altered lipid levels.

Roles of gender and obesity in defining correlations between perfluoroalkyl substances and lipid/lipoproteins

Study Purpose: This study looks at the relationship between PFASs and total cholesterol, LDL, HDL, and triglycerides and how gender and obesity change these relationships.

Study Conclusion: PFAS affected lipids such as LDL and total cholesterol more in obese individuals.

Associations between lipid/lipoprotein levels and perfluoroalkyl substances among US children aged 6-11 years

Study Purpose: Levels of lipids have been associated with exposure to PFASs. This study looks at the associations between PFASs and lipid levels in children aged 6-11 years.

Study Conclusion: PFOS and PFNA was related with total cholesterol levels in children and PFASs may be related to non-HDL cholesterol in children.

Metabolic health and metabolic syndrome

Liver and cardiometabolic markers and conditions in a cross-sectional study of three Australian communities living with environmental per- and polyfluoroalkyl substances contamination

Study Purpose: PFAS have been associated with higher cholesterol and liver function markers in some studies, but evidence has been inconclusive. This study assesses associations of single and combined PFAS chemicals with cardiometabolic markers in Australian communities with PFAS-contaminated water from firefighting activities.

Study Conclusion: This study is one of few that has assessed associations blood PFAS levels with multiple markers of cardiometabolic health in multiple communities. Findings for total cholesterol were consistent with previous studies.

Metabolic Signatures of Youth Exposure to Mixtures of Per- and Polyfluoroalkyl Substances: A Multi-Cohort Study

Study Purpose: Exposure to PFAS has been associated with an increased risk of cardiometabolic diseases. This study examines associations of PFAS mixtures with alterations in metabolic pathways in adolescents and young adults.

Study Conclusion: Exposure to PFAS is associated with alterations in amino acid and lipid metabolism in adolescents and young adults.

Associations between Per- and Polyfluoroalkyl Substances (PFAS) and Cardiometabolic Biomarkers in Adults of Czechia: The Kardiovize Study

Study Purpose: Even though there is evidence of decreasing trends of PFAS in Czechia, there are still major sources of PFAS pollution. Regarding the still-inconsistent results of the relationship between cardiometabolic health and PFAS, the present study sought to determine the association between PFAS levels and the presence of cardiometabolic biomarkers, including blood pressure, cholesterol, and other factors in a Czech population.

Study Conclusion: In conclusion, PFAS exposure in this population was lower than in other areas of the world. The results indicated that even with lower PFAS levels, it was possible to detect associations with cardiometabolic biomarkers, with results generally consistent with the literature. 

Associations of perfluoroalkyl substances with adipocytokines in umbilical cord serum: A mixtures approach

Study Purpose: PFAS may interfere with the secretion of adipokines and affect fetal metabolic function and intrauterine development. However, human data is limited. This study examines the associations of single and multiple PFAS exposures in utero with adipocytokine concentrations in umbilical cord serum.

Study Conclusion: PFAS levels were significantly associated with adipokines in cord serum, suggesting that intrauterine mixture of PFAS exposure may be related to decreased fetal leptin level but increased fetal adiponectin level and the associations may be sex-specific.

Characterization of Potential Adverse Outcome Pathways Related to Metabolic Outcomes and Exposure to Per- and Polyfluoroalkyl Substances Using Artificial Intelligence

Study Purpose: A new artificial intelligence tool was used to rapidly and systematically explore all published information to identify existing associations between PFAS and metabolic health outcomes.

Study Conclusion: The strength of the study lies in the identification and selection of complex and generalized information data on PFAS related to metabolic outcomes in a time-efficient manner due to the AOP-helpFinder tool. We were able to show that when considering PFAS as stressors in the AOP framework the potential interrelationships of different events and pathways can be revealed. That seems relevant for the further development of AOPs and AOP networks and should be further explored. Furthermore, we managed to provide an overview of the available data in the published scientific literature, which will help scientists obtain an easier understanding of potential linkages between MIE, KE, and AO in the case of metabolic outcomes initiated by PFAS exposure. This overview shows where information is lacking and points out where further research would be beneficial to support AOP development and hazard assessment.

Do perfluoroalkyl substances aggravate the occurrence of obesity-associated glucolipid metabolic disease?

Study Purpose: This article summarizes the literature on PFAS and obesity-related glucolipid metabolic disease, as well as experimental evidence.

Study Conclusion: Cross-sectional studies have reported that PFAS exposure increases the risk of GLMD, although this type of study cannot conclude causation. The occurrence of GLMD is also closely connected with obesity. However, there are few studies on this topic and more are needed.

Do perfluoroalkyl substances aggravate the occurrence of obesity-associated glucolipid metabolic disease?

Study Purpose: This article summarizes the literature on PFAS and obesity-related glucolipid metabolic disease, as well as experimental evidence.

Study Conclusion: Cross-sectional studies have reported that PFAS exposure increases the risk of GLMD, although this type of study cannot conclude causation. The occurrence of GLMD is also closely connected with obesity. However, there are few studies on this topic and more are needed.

Perfluorooctane sulfonate alternatives and metabolic syndrome in adults: New evidence from the Isomers of C8 Health Project in China

Study Purpose: Cl-PFESAs are alternatives to PFOS, a widely used PFAS. Despite evidence in the laboratory of metabolic toxicity, no study has explored associations of Cl-PFESAs with metabolic syndrome in a human population. To help address this gap, this study measured 32 PFAS, including Cl-PFESAs, in serum from 1228 adults participating in the cross-sectional Isomers of C8 Health Project in China.

Study Conclusion: These results suggest that exposure to Cl-PFESAs was associated with metabolic syndrome, though additional studies are needed to more definitively address potential health concerns of these PFOS alternatives.

To which extent are per-and poly-fluorinated substances associated to metabolic syndrome?

Study Purpose: This study assesses current literature investigating the association between exposure to PFAS and metabolic syndrome.

Study Conclusion: Based on this analysis, the current small body of evidence does not support an association between PFAS and metabolic syndrome. However, due to the small number of studies and differences between studies, results should be interpreted with caution. More studies are needed.

Prenatal exposure to persistent organic pollutants as a risk factor of offspring metabolic syndrome development during childhood

Study Purpose: This review looks at the role of prenatal exposure to persistent pollutants in offspring who develop metabolic syndrome in childhood, the latest research on metabolic syndrome, epidemiological and experimental findings on metabolic syndrome, and modes of action of persistent pollutants.

Study Conclusion: Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.

Associations of Perfluoroalkyl Substances with Prevalence of Metabolic Syndrome in Highly Exposed Young Adult Community Residents-A Cross-Sectional Study in Veneto Region, Italy

Study Purpose: This study investigates the associations between PFAS serum levels and the prevalence of metabolic syndrome among highly exposed young adults in north-eastern Italy stemming from PFAS water contamination.

Study Conclusion: These results did not support a consistent association between PFAS and metabolic syndrome.

Association between exposure to perfluoroalkyl substances and metabolic syndrome and related outcomes among older residents living near a Science Park in Taiwan

Study Purpose: The largest Science Park in Taiwan discharges wastewater containing PFASs into the Keya River, and a high concentration of PFASs have been found in this river and its aquatic life. This study looked at residents living near the river and evaluated the association of PFASs with metabolic syndrome and lipid levels.

Study Conclusion: These results showed that there were no associations between PFASs and metabolic syndrome. PFAS levels were associated with lipid levels. Certain PFASs were associated with increased uric acid levels, especially in males.

Other

Estimated exposure to perfluoroalkyl substances during infancy and serum-adipokine concentrations in later childhood

Study Purpose: The aim of the study was to evaluate the possible association of childhood adipokine concentrations with PFAS concentrations during infancy. Adipokines are molecules produced by  fat tissue that play roles in the bodies metabolism.

Study Conclusion: Increasing PFAS levels were associated with lower resistin concentrations at age 9 years. Resistin is a protein with links to both insulin resistance and inflammation. Additionally, there was some evidence of an association between increasing PFAS levels and increasing adiponectin levels. Adiponectin is a protein hormone involved in regulating glucose levels and breaking down fatty acids in the body.

Physical activity modifies the relation between gestational perfluorooctanoic acid exposure and adolescent cardiometabolic risk

Study Purpose: Exposure to PFAS may increase cardiometabolic risk. This study evaluates whether adolescent lifestyle factors modified associations between gestational PFAS exposure and cardiometabolic risk using a prospective cohort study.

Study Conclusion: Childhood physical activity modified the association between PFOA exposure with children's cardiometabolic risk, indicating that lifestyle changes may lessen the adverse effects of PFOA exposure.

Global DNA methylation mediates the association between serum perfluorooctane sulfonate and carotid intima-media thickness in young and middle-aged Taiwanese populations

Study Purpose: Previous reports have shown PFAS exposure may contribute to cardiovascular diseases (CVD). Recent studies have also identified a role for DNA methylation in the development of CVD. PFAS has also been shown to affect DNA methylation. This study investigates the association between PFOS and mean carotid intima-media thickness (CIMT), a marker of arteriosclerosis, and how this association may be affected by DNA methylation.

Study Conclusion: These results showed that PFOS exposure has direct associations on arteriosclerosis and indirect associations on arteriosclerosis through DNA methylation. The results suggest that DNA methylation might regulate the relationship between PFOS and arteriosclerosis in the study subjects. Additional works are required to understand the causal inference between PFOS, DNA methylation, and arteriosclerosis.

Prenatal and postnatal exposure to PFAS and cardiometabolic factors and inflammation status in children from six European cohorts

Study Purpose: In this study, they test the hypothesis that early life exposure to PFAS is associated with poor metabolic health in children. They studied the association between prenatal and postnatal PFAS mixture exposure and cardiometabolic health in children, and the role of inflammatory proteins.

Study Conclusion: This study supports the hypothesis that prenatal, rather than postnatal, PFAS exposure might contribute to unfavorable lipid profiles and adiposity in childhood.

Exposure to legacy and novel perfluoroalkyl substance disturbs the metabolic homeostasis in pregnant women and fetuses: A metabolome-wide association study

Study Purpose: This study evaluates the associations between metabolites in maternal and infant cord serum and exposure to several PFASs.

Study Conclusion: This study identified metabolites and pathways in pregnant women and fetuses associated with exposure to several PFASs.

Associations of Perfluoroalkyl substances with blood lipids and Apolipoproteins in lipoprotein subspecies: the POUNDS-lost study

Study Purpose: This study looks at the association between PFAS levels and lipoprotein (transports fats and lipids in blood) and apolipoprotein levels (transport fat and cholesterol in body).

Study Conclusion: These findings suggest that PFAS levels are associated with blood lipids and polyproteins, which may elevate cardiovascular risk.

Associations between repeated measure of plasma perfluoroalkyl substances and cardiometabolic risk factors

Study Purpose: PFASs may increase metabolic risks, but there are not many studies on the topic. This study looks at the associations between PFASs and total cholesterol, triglycerides, and hypertension.

Study Conclusion: This study found rising PFAS levels associated with lower triglyceride levels. There was no clear link between cholesterol or hypertension and PFASs.

Perfluoroalkyl substances and changes in body weight and resting metabolic rate in response to weight-loss diets: A prospective study

Study Purpose: Whether PFASs may interfere with body weight regulation is mostly unknown. This study looks at the associations of PFAS exposure with changes in body weight and resting metabolic rate in diet-induced weight-loss setting.

Study Conclusion: In this diet-induced weight-loss setting among overweight and obese individuals, higher levels of PFAS were associated with greater weight regain, especially in women.

Perfluoroalkyl substances, bone density, and cardio-metabolic risk factors in obese 8–12-year-old children: A pilot study

Study Purpose: PFASs have been associated with negative bone and metabolic changes in adults; however, these associations are understudied in children. This study looks at the relationships of PFASs with bone health in children.

Study Conclusion: PFAS exposure in obese children may play a role in adverse skeletal and cardiovascular risk profiles.

Serum perfluoroalkyl substances and cardiometabolic consequences in adolescents exposed to the World Trade Center disaster and a matched comparison group

Study Purpose: Children who lived or attended school near the World Trade Center disaster site were exposed to many substances, including PFASs. This study looks at the relationship of PFAS levels with lipid levels and weight.

Study Conclusion: There is a potential high risk of atherosclerosis (plaque buildup) and cardiovascular diseases in these children as a result of PFAS exposure.

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