Table 5-3 - Mobile Source Urban Hazardous Air Pollutants: 1990 Base Year

Table 5-3 - Mobile Source Urban Hazardous Air Pollutants: 1990 Base Year

(Estimated tons per year)

Chemical Onroad vehicles % of totala Nonroad aircraft % of totala Nonroad other % of totala
1,3 butadiene 36,920 47.7 854 1.1 16,628 21.5
Acetaldehyde 28,163 27.5 2,090 2.0 6,394 6.2
Acrolein 8,152 11.6 989 1.4 5,376 7.7
Arsenic and compounds 2 0.1 --   --  
Benzene 208,740 47.6 1,106 0.3 89,998 20.5
Chromium and compounds 28 2 --   17 1.2
Dioxins/furans 9.5 x 10­5 1.6 --   --  
Formaldehyde 97,506 35.6 6,791 2.5 26,864 9.8
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
Subtotal 381,314   12,219   145,551  
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 --   --  
Styrene 17,200 38.8 194 0.4 4,657 10.5
Total 454,705   12,412   15,232  

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.