© 1997 Oxford University Press
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Implementation of EPA Revised Cancer Assessment Guidelines: Incorporation of Mechanistic and Pharmacokinetic Data
* ToxaChemica, International, P.O. Box 10547, Gaithersburg, Maryland 20849
US EPA, NCEA-DC, Washington, DC 20460
Michigan State University East Lansing, Michigan 48824
CIIT, Research Triangle Park North Carolina 27709
||ICF/Kaiser Engineers, Research Triangle Park North Carolina 27709
¶ICF/Kaiser Engineers Ruston, Louisiana 71270
**Rohm & Haas Co. Spring House, Pennsylvania 19477
International Agency for Research on Cancer Lyon, Cedex 08, France
National Institute for Environmental Health Sciences, Research Triangle Park North Carolina 27709
Received January 27, 1997; A workshop entitled "Implementation of EPA Revised Cancer Assessment Guidelines: Incorporation of Mechanistic and Pharmacokinetic Data" was held in Anaheim, California, in 1996 at the 35th Annual Meeting of the Society of Toxicology (SOT). This workshop was jointly sponsored by the Carcinogenesis, Risk Assessment, and Veterinary Specialty Sections of the SOT. The thrust of the workshop was to discuss the scientific basis for the revisions to the EPA Guidelines for cancer assessment and EPA's plans for their implementation. This is the first revision to the original EPA guidelines which have been in use by EPA since 1986. The principal revisions are intended to provide a framework for an increased ability to incorporate biological data into the risk assessment process. Two cases were presented, for chloroform and trichloroethylene, that demonstrated the use of the revised guidelines for specific cancer risk assessments. Using these new guidelines, nonlinear margin of exposure analyses were proposed for these chemicals instead of the linearized multistage model previously used by the EPA as the default method. The workshop participants generally applauded the planned revisions to the EPA guidelines. For the most part, they considered that the revised guidelines represented a positive step which should allow for and encourage the use of biological information in the conduct of cancer risk assessments. Several participants cautioned however that the major problem with cancer risk assessments would continue to be the inadequacy of available data on which to conduct more scientific risk assessments.