Abstract |
Section 812 of the Clean Air Act Amendments of 1990 (CAAA) requires the U.S. Environmental Protection Agency (EPA) to perform periodic, comprehensive analyses of the total costs and total benefits of programs implemented pursuant to the Clean Air Act (CAA). EPA has completed two of these analyses: a retrospective analysis in 1997 of the original CAA covering the period 1970 to 1990, and a prospective analysis in 1999 of the incremental costs and benefits of the CAAA over the period 1990 to 2010. In both of these studies, estimation of the benefits of reduced concentrations of hazardous air pollutants (HAPs) has proved difficult, due to gaps in the toxicological database; difficulty in designing population-based epidemiological studies with sufficient power to detect health effects; limited ambient and personal exposure monitoring data; limited data to estimate exposures in some critical microenvironments; and insufficient economic research to support valuation of the types of health impacts often associated with exposure to individual HAPs. |