Table 4-42:  Estimated National Emissions of Volatile Organic Compounds (Million short tons) ,,,,,,,,,,,,,,,,,,
,1970,1975,1980 ,1985,1986,1987,1988,1989,1990 ,1991 ,1992 ,1993 ,1994 ,1995 ,1996 ,1997 ,1998 ,1999
TOTAL all sources,30.98,26.08,R26.33,24.43,23.62,23.47,24.31,22.51,R21.07,R21.26,R20.88,R21.11,R21.70,R20.93,R19.47,R19.75,R18.63,18.14
Transportation,,,,,,,,,,,,,,,,,,
On-Road vehicles,12.97,10.55,8.98,9.38,8.87,8.48,8.29,7.19,R6.44,R6.66,R6.29,R6.35,R6.56,R5.82,R5.54,R5.44,R5.44,5.30
Off-Road,,,,,,,,,,,,,,,,,,
  Aircraft,0.10,0.12,0.15,0.17,0.17,0.18,0.19,0.19,0.18,0.18,0.18,0.18,0.18,0.18,0.18,0.18,0.18,0.18
  Railroads,0.02,0.03,0.03,0.04,0.04,0.04,0.04,0.04,0.05,0.05,0.05,0.05,0.05,0.05,0.05,0.05,0.05,0.05
  Marine vessels,0.01,0.01,0.02,0.02,0.02,0.03,0.03,0.03,0.03,0.03,0.03,0.03,0.04,0.03,0.03,0.03,R0.03,0.03
  Other off-roada,0.87,0.93,0.98,1.03,1.02,1.01,1.01,0.96,0.92,0.92,0.91,0.91,0.92,0.93,R1.11,R1.12,R1.12,1.12
    Total transportation,13.97,11.64,10.16,10.64,10.12,9.74,9.56,8.41,R7.63,R7.85,R7.46,R7.52,R7.75,R7.00,R6.91,R6.82,R6.83,6.68
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Nontransportation,,,,,,,,,,,,,,,,,,
Fuel combustion,0.72,0.66,1.05,1.57,1.40,1.28,1.36,1.37,1.01,1.08,1.12,0.99,0.99,1.07,R1.07,R0.94,R0.86,0.90
Industrial processesb,12.33,11.10,12.10,9.50,9.35,9.58,9.90,9.81,9.01,9.18,9.37,9.53,9.69,9.71,R8.12,R8.34,R7.88,7.41
Waste disposal and recycling,1.98,0.98,0.76,0.98,0.97,0.95,0.96,0.94,0.99,1.00,1.01,1.05,1.05,1.07,0.42,R0.42,0.43,0.59
Miscellaneousc,1.98,1.71,R2.26,1.75,1.78,1.92,2.54,1.97,R2.43,R2.16,R1.92,R2.02,R2.22,R2.08,R2.95,R3.23,R2.64,d 2.56
    Total nontransportation,17.02,14.45,R16.17,13.80,13.50,13.73,14.76,14.09,13.44,R13.42,13.42,13.59,13.95,13.93,R12.56,R12.93,R11.80,11.46
KEY:  R = Revised.,,,,,,,,,,,,,,,,,,
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"a  Other off-road comprises nonroad gasoline- and diesel-powered recreational, airport service and railway maintenance vehicles, and recreational marine vessels.",,,,,,,,,,,,,,,,,,
"b  Industrial processes comprises chemical and allied product manufacturing, metals processing, petroleum and related industries, and other industrial processes; and solvent utilization, storage, and transport.",,,,,,,,,,,,,,,,,,
"c   Miscellaneous comprises nonroad gasoline- and diesel-powered construction, industrial, lawn and garden, farm, light-commercial, logging vehicles, and other nonroad sources; geogenic sources, catastrophic and accidental releases, health services, cooling towers, nontransportation-related fugitive dust, agriculture and forestry, structural fires, agriculture fires, slash/prescribed burning, forest wildfires,  and other combustion sources that could not be accurately allocated to specific source categories.",,,,,,,,,,,,,,,,,,
"d   Miscellaneous data for 1999 does not include emissions from geogenic sources, because the data was not estimated in 1999. The methodologies used for obtaining geogenic emission data are still being improved and current estimates will be revised at a later date.",,,,,,,,,,,,,,,,,,
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"NOTES:  The methodologies used to estimate emissions constantly evolve and undergo major changes.  These improved methods are often used to revise estimates for previous years.  Therefore, some estimates in this table may not match estimates produced in previous reports, and some trends may not be consistent across years in which major changes in methodology have occurred.",,,,,,,,,,,,,,,,,,
Numbers may not add to totals due to rounding.,,,,,,,,,,,,,,,,,,
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"SOURCES:  1970-1985, 1989-1999: U.S. Environmental Protection Agency, National Air Quality and Emissions Trends Report: 1999 (EPA-454/R-01-004) (Research Triangle Park, NC: March 2001), table A-5; available at Internet website http://www.epa.gov/oar/aqtrnd99/toc.html as of Sept. 5, 2001.",,,,,,,,,,,,,,,,,,
"1988: Ibid, National Air Pollutant Emission Trends: 1900-1998 (EPA-454/R-00-002) (Research Triangle Park, NC: March 2000), table A-3; available at Internet website http://www.epa.gov/ttn/chief/trends/trends98/browse.html as of Sept. 5, 2001.",,,,,,,,,,,,,,,,,,
"1986-87: Ibid, National Emission Trends Source Reports Database, available at Internet website www.epa.gov/air/data/nettier.html as of Sept. 5, 2001.",,,,,,,,,,,,,,,,,,
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