Air Pollution: Sulfur Dioxide Emissions From Nonferrous Smelters Have Been Reduced

Pursuant to a congressional request, GAO reviewed the Environmental Protection Agency's (EPA) and states' implementation of the Clean Air Act's provisions concerning copper, zinc, and lead smelters' sulphur dioxide emissions, including: (1) EPA measures to determine smelter compliance with the act and actions it took to enforce such compliance; and (2) factors EPA considered in exempting smelters from certain requirements of the act.