administrative mechanisms for supporting research, especially on the topic of assessment of hazardous PM components, suggest that EPA will need to enhance its efforts. Equally important will be the development of some form of a successor to this committee to provide continued monitoring and guidance to the efforts of EPA and others.
Much has been learned since 1998 research investment, and the evidence gained by the investment is already being used in the decisions that will continue to be made even with the uncertainties. Much is still to be learned. A failure to invest in advancing the understanding of the effects of PM and air pollution on health risks would result, in general, in not taking full advantage of the substantial research investment to date and limiting the nation’s ability to make evidence-based health policy and air quality regulatory choices in the future. Alternatively, continued enhancement of the air pollution and health research effort will undoubtedly yield substantial benefits for years to come. It is clearly the latter choice that offers the most promise to the nation in its effort to improve air quality and public health.