The U.S. Environmental Protection Agency

Polychlorinated biphenyls (PCBs) are syn-thetic chemicals that were produced commer-cially in the United States from 1929 to 1977 and used widely in the electrical industry because of their high stability, dielectric prop-erties, and resistance to oxidation (U.S. EPA and Environment Canada 2004). They were also used in plasticizers, adhesives, an