What are PCBs and DDTs?
PCB (polychlorinated biphenyl), a class of man-made chemical with world-wide industrial applications, and DDT (dichlorodiphyenyltrichloroethane), a pesticide, are both considered persistent organic pollutants and both have been banned in the U.S. for their harmful effects in wildlife and humans Even though these compounds have been banned for decades in the U.S., the levels of these compounds are still high in marine mammals sampled along our coasts. Both compounds are long lasting, reside in fat tissues (particularly in the blubber of marine mammals), and can be toxic causing such effects as reproductive impairment and immunosuppression. The actual impacts these compounds have on marine mammals is still unknown, but similar levels in other mammals has shown impacts on health, survival and reproductive function. The United Nations Environment Program is leading international negotiations to ban 12 persistent organic pollutants including DDT and PCB.
