of the Nation's Highways, Bridges, and Transit:
2002 Conditions and Performance Report
Total Emissions of Carbon Monoxide, NOx, VOCs, and PM-10, 1970-1999
Exhibit 19-6 is a chart that shows total emissions of carbon monoxide, NOx, VOCs, and PM-10 from 1970 to 1999. The vertical axis measures short tons in thousands from 0 to 200,000 in increments of 50,000 thousand. The horizontal axis measures the years from 1970 to 1999 in increments of 5 years. The first of three lines, for stationary and area, started at 60,000, dropped to 50,000 in 1975 and 1980, and gradually decreased to about 40,000 by 1999. The second line, for on-road mobile, started at about 170,000, dropped to 150,000 from 1975 to 1985, and ended at 110,000 from 1990 to 1999. And the third line, for non-road mobile, started at 180,000, dropped to 160,000 from 1975 to 1985, and ended at 140,000 from 1990 to 1999.
Source: National Air Quality and Emissions Trends Report, 1999, EPA OAQPS, Research
Triangle Park, NC, March 2001.