Using Science to Shape Policy

The Clean Air Act (CAA) is responsible for dramatically improving United States air quality over the last 40 years. The scientific community has served as the backbone of that improvement. Experimental sciences, animal toxicology and controlled human exposures, have played valuable roles in deciphering the mechanisms of air pollution-related health effects and in some cases clearly demonstrating the overt health effects that result from exposure to air pollutants. However, at times the research community is unaware of how their contributions to science are used to inform policy decisions in the context of the National Ambient Air Quality Standards (NAAQS). Within this chapter, researchers will gain a better understanding of the legislative history and requirements of the CAA. Additionally, the chapter will detail how the U.S. Environmental Protection Agency evaluates the scientific evidence that forms the basis of each NAAQS along with the resulting steps taken to inform policy decisions. The chapter will conclude with a discussion of the uncertainties that still shape air quality policy, the shift that has taken within the air pollution research community towards the examination of multipollutant exposures, and the potential future of air quality policy.