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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

7-6 Highway Vehicle Air Pollutant Emissions: 2002–2013

Wednesday, January 7, 2015

Graphic Version | Excel

Index: 2002 = 1.0

Year Carbon monoxide Nitrogen oxide Volatile organic compounds PM-10 PM-2.5 Sulfur dioxide Ammonia
2002 1.00 1.00 1.00 1.00 1.00 1.00 1.00
2003 0.94 0.94 0.95 0.98 0.98 0.87 0.98
2004 0.89 0.87 0.91 0.97 0.96 0.73 0.96
2005 0.83 0.81 0.86 0.95 0.93 0.60 0.94
2006 0.78 0.77 0.86 0.94 0.90 0.37 0.94
2007 0.72 0.74 0.87 0.92 0.86 0.15 0.95
2008 0.64 0.67 0.76 0.83 0.77 0.14 0.89
2009 0.54 0.60 0.69 0.76 0.69 0.13 0.83
2010 0.55 0.55 0.69 0.70 0.61 0.13 0.78
2011 0.52 0.56 0.60 0.72 0.63 0.10 0.77
2012 0.50 0.52 0.57 0.69 0.60 0.10 0.75
2013 0.48 0.48 0.54 0.67 0.56 0.10 0.72

Key: PM-10 = airborne particulates of less than 10 microns; PM-2.5 = airborne particulates of less than 2.5 microns.

Notes: Indices are calculated using data on highway vehicle emissions only. Particulate matters include PM without condensibles.

Source: As cited in U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics, tables 4-45 through 4-50, available at www.bts.gov as of September 2014.