SCIENCE AND POLICY IN REGULATORY DECISION-MAKING - GETTING THE FACTS RIGHT ABOUT HAZARDOUS AIR-POLLUTANTS

Hazardous air pollutants are regulated under Title III of the 1990 Cle an Air Act Amendments. The Amendments replace the risk-based approach mandated in the 1977 Amendments with a prescriptive. technology-based approach requiring that maximum achievable control technology (MACT) b e applied to all major industrial sources of 189 hazardous air polluta nts. The change reflects political, rather than scientific consensus t hat the public health benefits justify the costs. The choice is put in to perspective by looking at the interface between science and policy that occurs as part of regular decisionmaking. Particular emphasis is given to examining the interrelationships among facts (science), judgm ents (science policy), and policy (values) in the context of the risk assessment paradigm. Science and policy are discussed in relation to T itle III, contrasting the political consensus for action with the scie ntific uncertainty about risks and benefits. It is argued that a balan ced research program is needed to get the facts right about hazardous air pollutants, including research to meet statutory requirements, to reduce uncertainties in risk assessment. and to address strategic issu es.