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Title: Acid rain reduced in Eastern United States

Concentrations of sulfate (SO{sub 4}{sup 2{minus}}) and free hydrogen ions (H{sup +}) in precipitation decreased from 10% to 25% over a large area of the Eastern US from 1995 through 1997 as compared to the previous 12-year (1983--1994) reference period. These decreases were unprecedented in magnitude and spatial extent. In contrast, nitrate (NO{sub 3}{sup {minus}}) concentrations generally did not change over this period. The largest decreases in both H{sup +} and SO{sub 4}{sup 2{minus}} concentrations, which nearly mimicked one another, occurred in and downwind of the Ohio River Valley, the same area where Title 4 of the 1990 Clean Air Act Amendments (CAAA) set limitations on sulfur dioxide (SO{sub 2}) emissions from a large number of utility-owned coal-fired sources. Phase 1 of the CAAA required that these limitations be met by January 1, 1995. On the basis of their analysis of precipitation chemistry and emissions data, the authors conclude that significant declines in acid rain occurred in many parts of the Eastern US from 1995 through 1997 because of large reductions in SO{sub 2} emissions in this region and a corresponding reduction in SO{sub 4}{sup 2{minus}} concentrations in precipitation.
Authors:
; ;
Publication Date:
OSTI Identifier:
20020672
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environmental Science and Technology; Journal Volume: 34; Journal Issue: 6; Other Information: PBD: 15 Mar 2000
Research Org:
Pennsylvania State Univ., University Park, PA (US)
Country of Publication:
United States
Language:
English
Subject:
20 FOSSIL-FUELED POWER PLANTS; ACID RAIN; AIR POLLUTION ABATEMENT; SULFATES; SULFUR DIOXIDE; HYDROGEN IONS 1 PLUS; NITRATES; ECOLOGICAL CONCENTRATION; FOSSIL-FUEL POWER PLANTS; WASTE MANAGEMENT