Annual Hajj Pilgrimage Contributes to Dangerous Air Pollution in Mecca

The annual hajj pilgrimage to Mecca, Saudi Arabia, which attracts about 3-4 million people per year, exposes travelers to harmful air pollution that increase the risk of people developing adverse health conditions such as heart failure, respiratory illness, nausea and dizziness. The influx of travelers commuting to the holy site by various modes of transportation such as by foot, car, or train, intensifies existing levels of air pollution in Mecca.

During the 2012 and 2013 pilgrimages, research scientists from the University of California, Irvine (UCI), King Abdulaziz University in Saudi Arabia, the University of Karachi in Pakistan, the New York State Department of Health's Wadsworth Center, and the University at Albany, SUNY collected data and analyzed air quality samples along roadsides, massive air-conditioned tents, and tunnels that led people to the Grand Mosque.

Analyses showed inside the Al-Masjid Al-Haram tunnel had the worst air quality measured, with carbon monoxide levels measuring 57,000 parts per billion during the October 2012 hajj. Pilgrims who traveled through the tunnel by foot, hotel workers and security personnel were exposed to vehicle exhaust from automobiles traveling through the tunnel. Furthermore, the researchers found high levels of black carbon and fine particulate matter that sink deep into lung tissues.

In addition to vehicle exhaust, gasoline with high benzene concentrations, gas station fuel nozzles that lack vapor locks, and older cars with brake liners that are disintegrating, were cited as possible problems that contribute to poor air quality in the area. Coolants used for air-conditioned sleeping tents also add to greenhouse gas buildup and further impact air quality. Officials in Saudi Arabia have already taken the initiative to address air quality issues by working to reduce benzene levels in gasoline supplies. The researchers also recommend separating pedestrians and vehicles into different tunnels, and using available technologies to reduce air pollution.

On December 15, 2014, during the American Geophysical Union meeting in San Francisco, Haider Khwaja, a research scientist at the Wadsworth Center and an assistant professor at the School of Public Health, University at Albany, SUNY, stated "Air pollution is the cause of one in eight deaths and has now become the single biggest environmental health risk globally. There were 4.3 million deaths in 2012 due to indoor air pollution and 3.7 million deaths because of outdoor air pollution, according to WHO. And more than 90 percent of those deaths and lost life years occur in developing countries." Khwaja expressed his firsthand experience with poor air quality as a child living inĀ  Karachi, Pakistan. "Suffocating," is how he described the air quality.