Air toxics in the U.S.: magnitude of the problem and strategy for control.

Over the past several years, substantial concern has been expressed by some in Congress, environmental groups, and members of the public concerning the lack of progress in regulating toxic air pollutants by the U.S. Environmental Protection Agency (EPA). As a result, a number of amendments to the Federal Clean Air Act have been introduced to require EPA to regulate in a relatively rapid timeframe, a large number of potentially toxic pollutants that are released to the ambient air. This paper discusses EPA's current understanding of the magnitude and nature of the air toxics problem in the U.S., and the pollutants and source categories that pose the most significant risk to the public. The focus of the discussion is on routine releases, as opposed to catastrophic, accidental releases such as the one in Bhopal, India. The paper then discusses the strategy that EPA has put in place to deal with the problem and presents the status of a number of regulatory and non-regulatory activities under way to better understand the problem and to mitigate it. The strategy involves important roles for: (1) EPA to regulate national problems using a variety of Federal authorities in addition to the Clean Air Act, and (2) States to develop their own air toxic control programs to deal with unique local problems involving high risk point sources and multipollutant, multisource problems in large urban or industrialized areas.