(Estimated tons per year)
|Chemical||Onroad vehicles||% of totala||Nonroad aircraft||% of totala||Nonroad other||% of totala|
|Arsenic and compounds||2||0.1||--||--|
|Chromium and compounds||28||2||--||17||1.2|
|Dioxins/furans||9.5 x 105||1.6||--||--|
|Lead and compounds||1,690||35.8||384||8.1||197||4.2|
|Manganese and compounds||22||0.7||--||20||0.6|
|Nickel and compounds||16||0.9||--||9||0.5|
|Polycyclic organic matter as 16-PAH||76||0.3||5||<0.1||47||0.2|
|Polycyclic organic matter as 7-PAH||34||1.7||<0.1||<0.1||24||1.2|
|Polycyclic organic matter as EOM||56,157||13.9||--||--|
a Percentage of total emissions, all sources, both urban and rural.
KEY: EOM = extractable organic matter; PAH = polycyclic aromatic hydrocarbon; -- = less than 0.01 or no estimate made.
NOTES: Chemicals in italics are those for which the Environmental Protection Agency estimated base-year emissions data; they are not included on the current list of 33 draft urban hazardous air pollutants (HAPs).
SOURCES: For data: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Quality Strategies and Standards Division and Emissions, Monitoring, and Analysis Division, 1990 Emissions Inventory of Forty Section 112(k) Pollutants, Interim Final Report, available at www.epa.gov/ttn/uatw/urban/112kfac.html, January 1998.
List of 33 draft urban HAPs:
U.S. Environmental Protection Agency, Office of Air and Radiation, Air Quality Planning and Standards, National Air Quality and Emissions Trends Report, 1997, 454/R-98-016, December 1998, available at www.epa.gov/oar/aqtrnd97/, table 5-4.