Trends in visibility, PM-2.5, and deposition expected from the Acid Rain Provisions of the 1990 Clean Air Act Amendments

摘要

The Acid Rain Provisions (Title IV) of the 1990 Clean Air Act Amendments (CAAA) are designed to reduce the deposition of SO2 and sulfate and, to a lesser extent, the deposition of NOx and nitrate through reduction of SO2 and NOx emissions. However, other important benefits are anticipated from the emission control strategies, including improvement of regional visibility and reductions in concentrations of fine particles (PM-2.5). In this study, the authors coupled utility emissions forecasts with the Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model and the Visibility Assessment Scoping Model (VASM) to calculate and compare the relative improvements by 2010 in visual impairment, PM-2.5 concentrations, and sulfate wet deposition at selected sites in the eastern United States.