Quantitative Dose-Response Assessment of Inhalation Exposures to Toxic Air Pollutants

摘要

Implementation of the 1990 Clean Air Act Amendments, including evaluation of residual risks, requires accurate health risk estimates of both acute and chronic inhalation exposure to toxic air pollutants. The U.S. Environmental Proection Agency's National Center for Environmental Assessment, Research Triangle Park, NC, has a research program that addresses several key issues for development of improved quantitative approaches for dose-response assessment. This paper describes three projects underway in the program. Project A describes a Bayesian approach that developed to base dose-response estimates on combined data sets and that expresses these estimates as probability density functions. The Bayesian approach offers the same advantage as the benchmark dose (BMD) approach, but additionally provides for formal statistical combination of the data regardless of how the effect was measured (e.g., quantal or continuous), can incorporate variability in the "dose" estimate directly, and expresses the dose-response estimate as a probability density distribution that is directly amenable with probabilistic estimates of exposure or with probabilistic uncertainty distributions.