Air Pollution: Information on EPA's (Environmental Protection Agency's) Efforts to Control Emissions of Sulfur Dioxide

摘要

As required by the Clean Air Act, the Environmental Protection Agency (EPA) established national ambient air quality standards for sulfur dioxide and five other widespread pollutants. While EPA has set these standards at levels intended to protect the public's health and welfare, the states are responsible for developing implementation plans to achieve the standards and assure that necessary measures are adopted to prevent unhealthy emissions. Over and above the health risks associated with sulfur dioxide emissions, its contribution to the formation of acid rain has also prompted congressional concerns. To address acid rain concerns, lawmakers have introduced several legislative proposals mandating large-scale reductions in sulfur dioxide emissions. The report responds to questions about EPA's state implementation plan revisions and to provide an update on the number of revisions. It contains additional information on the status of EPA's efforts to develop two models - the Regional Acid Deposition Model (RADM) and the Complex Terrain Dispersion Model (CTDM) - to improve its ability to estimate the movement and effect of sulfur dioxide and other airborne pollutants. Specifically, it determined for each model the purpose, costs, current status, planned completion dates, and expected performance when completed.