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6-4 Index of Key Air Pollutant Emissions from U.S. Transportation: 1990-2006

Tuesday, December 27, 2011

6-4 Index of Key Air Pollutant Emissions from U.S. Transportation: 1990-2006

Index: 1990 = 1.0

Excel | CSV | Graphic Version

Year Carbon monoxide
CO		 Nitrogen oxide
NOx		 Volatile organic compounds
VOC		 Particle matters Surfur dioxide
SO2		 Ammonia
NH3
PM-10 PM-2.5
1990 1.00 1.00 1.00 1.00 1.00 1.00 1.00
1991 0.95 0.99 0.94 0.96 0.95 0.93 1.09
1992 0.90 0.97 0.89 0.91 0.90 0.87 1.17
1993 0.86 0.96 0.83 0.87 0.85 0.80 1.26
1994 0.81 0.94 0.78 0.83 0.81 0.73 1.35
1995 0.76 0.93 0.72 0.79 0.76 0.67 1.43
1996 0.71 0.91 0.66 0.74 0.71 0.60 1.52
1997 0.69 0.92 0.64 0.71 0.67 0.60 1.71
1998 0.66 0.90 0.62 0.66 0.62 0.60 1.65
1999 0.62 0.87 0.61 0.62 0.57 0.60 1.72
2000 0.62 0.88 0.57 0.59 0.54 0.52 1.77
2001 0.58 0.81 0.53 0.55 0.49 0.49 1.79
2002 0.57 0.85 0.50 0.52 0.46 0.51 1.87
2003 0.55 0.81 0.47 0.51 0.44 0.48 1.91
2004 0.53 0.77 0.45 0.50 0.42 0.44 1.95
2005 0.51 0.73 0.43 0.48 0.40 0.41 2.00
2006 0.49 0.69 0.41 0.47 0.38 0.37 2.05

Key: PM-10 and PM-2.5 = airborne particulates of less than 10 microns or 2.5 microns, respectively.

Notes: Data in the previous edition include all onroad mobile sources and some nonroad mobile sources. EPA revised the emissions estimation methodology for onroad mobile sources.

Source: U.S. Environmental Protection Agency, Clearinghouse for Inventories and Emissions Factors (CHIEF), Current Emission Trends Summaries, Internet website http://www.epa.gov/ttn/chief/trends/index.html as of September 2007.