Document VGv7RnKGL4RVQqey9RR3nx0Yq

-j'flN.24.1997 2:27PM FLEISHMAN HILLARD| NO.259 P.2/3 EPA softens PCB potency warnings Millions of dollars may be saved on cleanup while health concerns still linger By SARA THURIN ROLLIN Several companies, including GE, chal water. EPA will also be able to back up Twenty years after Congress banned lenged EPA's 1992 sjs-ealled national tox those statements with data. manufacture of polychlorinated biphenyls ics rule, which set water pollution stan Because PCBs are widespread in the (PCBs), in part due to their cancer threat, dards for PCBs amopg other chemicals environment, people are exposed through new test data and modem risk assessment (American Forest and Paper Association contamination of air, water, sediment, techniques have triggered the Environ v. EPA, DC, No. 93 -0694, partial settle soil, and certain foods, according to the mental Protection Agency to reduce its ment 11/15/95). agency. Due to a lack of data, EPA said it cancer risk estimates for these chemicals. The three risk as sessment techniques previously treated all PCBs in all environ Downgrading was done not because responsible for the i eduction in potency mental settings alike. PCBs were proven to be less hazardous estimates are the use if: The new data will allow government than previously thought. In fact, data from a modern tuipor classification risk assessors to adjust the risk estimates new studies confirmed PCBs' cancer scheme; to account for environmental processes threat, and documented a new area where that could act to either increase or they might cause problems--the thyroid. The new test data confirms and strengthens the agency's previous finding cience decrease the chemicals' toxicity, Cogliano said. This is important because the composition of PCB mixtures in the that all PCBs pose some cancer threat, including those with low chlorine content, urvej environment changes over time, such as preferential bioaccumulation, where according to Jim Cogliano, the lead EPA certain PCBs accumulate selectively in scientist for the PCB reassessment project. a revised cross-species scaling factor, living organisms, according to the report. Nonetheless, the reassessment is expected which is used to estimate a dose in Cancer risk rises as chlorine content to lead to a relaxation of PCB cleanup and humans based on dos is given to rodents; of the PCB increases, according to EPA. water pollution standards. a new approach for estimating expo Because bioaccumulation through the The reduced cancer numbers are the sure in the underlying studies food chain tends to concentrate PCBs with result of modem assessment techniques The new thyroid cancer finding, seen higher chlorine content, people exposed applied to a large set of data, making it only in male rats, was not unexpected, through the food chain would face the possible to distinguish between types of Cogliano said, explaining that structurally highest cancer risk. Populations of poten PCBs, some of which are more dangerous similar dioxins and furans cause this tially highly exposed people include nurs than others. Using three new risk assess effect. The chemical testing, completed ing infants and people whose diet is high ment techniques to generate cancer poten during the summer pf 1996, was spon in game fish, game animals, or highly cy estimates, Cogliano said, enabled EPA sored by the General Electric Co. contaminated animal products. to generate cancer potency estimates on PCBs exist as mixtures of combina At the same time as EPA was relax four PCBs that were sold widely in the tions of the 209 different congeners. The ing its cancer potency estimates, new data United States until their manu suggesting that PCBs pose a facture was banned in 1977. A cancer potency estimate is a mathematical expression of the cancer-causing potential of a substance. The four new PCB potency estimates adopt ed by EPA on Oct. 1 were about one-third that of the val The anticipated regulatory changes, such as a relaxed cleanup]standard, may save companies and governments millions of dollars in hazardous waste cleanup costs because 25 percent of all federal superfund sites have PCB contamination. developmental threat to chil dren were being published and concern about their potential to disrupt the hormone systems in humans and wildlife are unre solved. A Sept. 12 New England Journal of Medicine article described developmen ues set in 1988. Both state and tal deficiencies observed in federal agencies consult EPA's cancer assessments when setting standards. The anticipated regulatory changes, commercial mixturei made in the United States are called Arokors. The Aroclors in the GE studies repreWt about 90 percent children who had been exposed to PCBs through their mothers' diets and breast feeding. such as a relaxed cleanup standard, may of all U.S. production between 1957-1977, Among the policy questions EPA save companies and governments millions according to the com ?any. must resolve is whether protecting people of dollars in hazardous waste cleanup The new laborat iry data and resulting from PCB's cancer threat also will protect costs because 25 percent of all federal potency estimates }Uow EPA to make them from possible non-cancer problems, superfund sites have PCB contamination, some distinctions about PCBs in the envi according to Dr. Lynn Goldman, a pedia most notably PCBs in soil, according to ronment, Cogliano said, such as the fact trician and head of EPA's pesticides and EPA. Demand for the PCB reassessment that those in fish cause much more con toxic substances office. came from Congress and the courts. cern than PCBs dissolved in drinking EPA scientists said there probably are 16 Winter 1996-97 SFJourrud. P.O.Box272m. Philadelphia. PA 191 IB DSW 133264 STLCOPCB4033222 TAN.24.1997 2:27PM FLEISHMAN HILLARD P.3/3 not enough data yet to do a quantitative risk assessment for non-cancer effects of PCBs to resolve that question or resolve the endocrine disruption concerns. PCBs, however, seem to make every list of "potential endocrine disruptors" and are the focus of much research. An inventory of ongoing federal endocrine disruption research shows of the 333 substances being studied, 109 are PCBs. Cogliano suggested that resolution of these non-cancer questions is still a long way off. Copies of the EPA report, "PCBs: Cancer Dose-Response Assessment and Application to Environmental Mixtures," are available on the internet [http://www.epa.gov/ORD/ WebPubs/pcb] and for a fee from the National Technical Information Services (703) 487-4460. Sara Tkurin Rollin is a reporter for the Bureau ofNational Affairs, Inc. CSW 133265 STLCOPCB4033223