The report gives results of an analysis of national and regional acid deposition precursor emission trends, involving SOx, NOx, and VOCs. While the focus is on emissions during 1980-1985, comparisons are made (for perspective) with emission trends for 1940-1980. Study methods integrated data from the U.S. EPA's national emission trends reports, state and regional activity indicators, and plant level data for electric utilities and copper smelters. For 1980-1985, all three pollutants showed both annual declines and increases. For a longer term, emission trends can be divided into three periods: (1) 1940 to the mid-1970s, when emissions increased in proportion to fuel use and the GNP; (2) the late 1970s to the early 1980s, the emissions control era, when Clean Air Act programs produced a downward trend for all pollutants except NOx as the economy continued growing; and (3) since 1980, when relationships between emissions and the economy, fuel use, and regulations are making it more difficult to predict emissions in future years.

Caption title. "Mar. 1989." "EPA/600/8-89/042." Microfiche.