response to this request, NRC convened the Committee on Human Health Risks of Trichloroethylene, which prepared this report.
The committee was asked to identify and assess the key scientific issues relevant to analyzing the human health risks of trichloroethylene. In performing its task, the committee was asked to consider pertinent toxicologic, epidemiologic, population susceptibility, and other available information, including relevant published scientific literature, EPA’s 2001 draft health risk assessment of trichloroethylene, scientific and technical comments received by EPA from public and private sources, and additional relevant information to be provided by the sponsoring agencies. The committee was tasked with holding one or more information-gathering sessions open to the public to gain additional insights into the issues from federal agencies, concerned parties, and other scientists.
The committee was asked to highlight issues critical to the development of an objective, realistic, and scientifically balanced trichloroethylene health risk assessment. The focus was to be on hazard characterization and mode of action for trichloroethylene toxicity, possible approaches to synthesize epidemiologic data in informing the hazard characterization of trichloroethylene, differential susceptibility in different subpopulations or life stages, the evidence for effects from trichloroethylene exposures alone compared with that for effects from mixtures of chemicals that include trichloroethylene, physiologically based pharmacokinetic modeling, dose-response assessment, and quantitative assessment of cancer and noncancer risks. The availability of appropriate data and methods to implement the committee’s advice as well as the distinction between data analysis and data generation were to receive special attention. The committee was asked to distinguish between issues that can be addressed through short-term analyses and issues that are more appropriately addressed through medium- or long-term research projects.
The committee was not asked to develop its own risk assessment or to address any risk management issues.
The committee held five meetings between March and November 2005. The first three meetings involved data-gathering sessions, where the committee heard from sponsors, invited speakers, representatives of citizen groups, and members of the public. The committee reviewed a large body of written material on trichloroethylene, including research articles, literature reviews,