Bureau of Transportation Statistics (BTS)
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Table 7-7: Air Pollution in the 50 Largest Metropolitan Areas: 2000-2006

(Number of days with AQI values greater than 100)

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Metropolitan area AQI days > 100
2000R 2001R 2002R 2003R 2004R 2005R 2006
Atlanta, GA 39 24 20 12 12 11 18
Austin-San Marcos, TX 6 0 5 3 2 1 3
Baltimore, MD 23 33 42 20 16 25 20
Bergen-Passaic, NJ 1 1 1 2 1 4 2
Boston, MA-NH 0 3 9 8 1 4 1
Charlotte-Gastonia-Rock Hill, NC-SC 22 13 27 4 5 11 8
Chicago, IL 13 33 20 10 9 23 5
Cincinnati, OH-KY-IN 15 16 30 10 4 13 2
Cleveland-Lorain-Elyria, OH 21 27 30 14 16 20 6
Columbus, OH 12 14 21 9 1 8 1
Dallas, TX 20 14 7 5 9 10 13
Denver, CO 2 8 7 17 0 1 6
Detroit, MI 15 31 26 19 5 24 6
Fort Lauderdale, FL 3 3 3 0 0 0 2
Fort Worth-Arlington, TX 17 17 23 25 11 22 19
Greensboro-Winston-Salem-High Point, NC 14 11 24 4 1 2 4
Houston, TX 42 28 21 31 22 28 18
Indianapolis, IN 8 13 24 11 1 17 2
Kansas City, MO-KS 10 4 7 11 0 9 11
Las Vegas, NV-AZ 0 1 2 2 0 2 2
Los Angeles-Long Beach, CA 63 81 81 88 65 43 34
Miami, FL 2 1 1 1 3 0 1
Milwaukee-Waukesha, WI 5 20 10 9 6 16 4
Minneapolis-St. Paul, MN-WI 6 6 1 1 0 2 0
Nashville, TN 20 7 16 7 1 10 6
Nassau-Suffolk, NY 5 5 14 7 3 10 5
New Orleans, LA 20 6 2 8 5 4 4
New York, NY 19 19 27 11 6 15 11
Newark, NJ 12 18 29 11 7 11 13
Norfolk-VA Beach-Newport News, VA-NC 5 7 15 4 2 1 3
Oakland, CA 10 11 21 7 7 5 10
Orange County, CA 5 6 4 5 3 0 5
Orlando, FL 3 4 1 0 0 5 1
Philadelphia, PA-NJ 21 34 35 19 9 21 18
Phoenix-Mesa, AZ 14 8 10 8 1 6 7
Pittsburgh, PA 32 50 50 37 39 48 36
Portland-Vancouver, OR-WA 6 2 6 0 3 2 2
Providence-Fall River-Warwick, RI-MA 5 14 13 3 2 6 2
Raleigh-Durham-Chapel Hill, NC 8 4 18 5 1 3 0
Riverside-San Bernardino, CA 144 153 146 138 116 103 97
Sacramento, CA 41 47 57 36 26 39 43
St. Louis, MO-IL 20 20 33 13 2 27 12
Salt Lake City-Ogden, UT 19 25 27 10 37 24 11
San Antonio, TX 0 0 17 4 4 3 2
San Diego, CA 31 30 20 20 16 7 15
San Francisco, CA 4 12 17 1 4 5 2
San Jose, CA 20 12 9 6 2 6 5
Seattle-Bellevue-Everett, WA 8 6 7 2 1 3 5
Tampa-St. Petersburg-Clearwater, FL 8 4 0 5 0 4 2
Washington, DC-MD-VA-WV 20 27 33 12 10 18 18

KEY: AQI = Air Quality Index, R = revised

NOTES: The Air Quality Index (AQI) integrates information on 6 major pollutants (particulate matter less than 10 microns in diameter, particulate matter less than 2.5 microns in diameter, sulfur dioxide, carbon monoxide, ozone, and nitrogen dioxide) across an entire monitoring network into a single number that represents the worst daily air quality experienced in an urban area. An AQI greater than 100 indicates that at least 1 criteria pollutant exceeded air quality standards on a given day; therefore, air quality would be in the unhealthful range on that day. Metropolitan area rank is based on populations and geographic definitions for 2000.

The U.S. Environmental Protection Agency reports data for metropolitan areas as they were defined in 2000.

SOURCE: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Trends, available at http://www.epa.gov/air/airtrends/index.html as of Dec. 7, 2007



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