There are historical incidences of acute exposures to humans that resulted in serious health impacts. In two separate incidents, humans in Japan and Taiwan who ate PCB-contaminated food developed skin pigmentation problems as well as central nervous system disorders. Equally disturbing, the children of the exposed parents had lower birth weights, were shorter than normal, and also experienced behavioral problems. Because PCBs are stored in fat tissue, these children were exposed while being carried by their mothers and also while they were being nursed. Because breastmilk is high in fat, through childbirth and nursing, mothers are able to reduce their body burdens of PCBs and other similar organic contaminants. Otherwise, the PCBs remain in the body until the stored fat is eliminated through weight loss.