Trichloroethylene health risk assessment: a new and improved process.

Trichloroethylene (TCE), an environmental contaminant of National concern, is the focus of a new health risk assessment process incorporating the Proposed Cancer Risk Assessment Guidelines. This paper describes not only how TCE became an environmental problem for the Air Force, but also details the new Risk Assessment process envisioned by the Environmental Protection Agency's (EPA) National Center for Environmental Assessment (NCEA). Insights on epidemiological evaluations, both past and future, and their impact on the cancer classification of TCE are discussed. Examples of how physiologically based pharmacokinetics and dose-response characterization described in the new Cancer Guidelines are applied to TCE are provided. In addition, a variety of modeling techniques are discussed for the development of reference doses (oral exposure) and reference concentrations (inhalation exposures) for TCE. Finally, the role of risk communication is included. This new process provides an example of how interagency (EPA, Department of Defense. Department of Energy) and extramural (industry, academia) partnerships can provide greater gains to the nation, as a whole, than any of the parts on their own.