(a) Not statistically significant.
(b) Based on percentage change from 1999.
(c) Includes only directly emitted particles.
(d) Based on percentage change from 1985. Emission estimates
prior to 1985 are uncertain.
(e) Lead emissions are included in the toxic air pollutant emissions
inventory and are presented for 1982-2001.
Source: Latest Findings on National
Air Quality: 2002 Status and Trends. U.S. Environmental Protection
Agency, EPA454/K-03-001, Office of Planning and Standards, Research
Triangle Park, NC 27711, September 2003.