Despite Challenges, IRIS Staff Defend Plan To Assess PCB Mixtures' Risks

摘要

EPA staff is acknowledging the challenges in assessing the human health risks of exposure to mixtures of polychlo-rinated biphenyls (PCBs), in part due to the varied nature of the mixtures that occur in the environment and new data about their non-cancer risks, but an existing assessment may provide a template for the new effort. There are 209 PCB congeners, chemicals that were developed and used starting about 1930 until EPA banned their use in 1979. EPA's planning and scoping document for its pending Integrated Risk Information System (IRIS) assessment of the human health risks of PCBs estimates that "more than 600 million [kilograms] of PCBs were commercially produced in the United States," due to their multitude of uses in electrical applications for insulating and inflammability, as well as other uses in paints, inks, coatings, sealants, caulks and others.