Table 7-7: Air Pollution in the 50 Largest Metropolitan Areas: 2002-2009

Table 7-7: Air Pollution in the 50 Largest Metropolitan Areas: 2002-2009

(Number of days with AQI values greater than 100)

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Metropolitan area AQI days > 100
2002 (R) 2003 (R) 2004 (R) 2005 (R) 2006 (R) 2007 (R) 2008 (R) 2009
Atlanta-Sandy Springs-Marietta, GA 44 24 22 32 46 40 25 11
Austin-Round Rock, TX 8 9 8 9 13 4 2 4
Baltimore-Towson, MD 59 30 31 36 33 45 23 11
Birmingham-Hoover, AL 28 31 17 37 36 41 12 5
Boston-Cambridge-Quincy, MA-NH 10 8 1 4 1 3 0 0
Buffalo-Niagara Falls, NY 96 61 69 40 15 38 4 1
Charlotte-Gastonia-Concord, NC-SC 41 12 16 25 21 33 16 2
Chicago-Naperville-Joliet, IL-IN-WI 46 37 28 53 28 52 46 24
Cincinnati-Middletown, OH-KY-IN 81 57 52 57 23 44 14 5
Cleveland-Elyria-Mentor, OH 86 72 62 89 64 60 54 3
Columbus, OH 38 12 3 20 5 13 4 1
Dallas-Fort Worth-Arlington, TX 40 40 32 56 39 16 20 19
Denver-Aurora, CO 15 23 4 10 21 16 4 4
Detroit-Warren-Livonia, MI 54 37 37 62 38 35 24 9
Hartford-West Hartford-East Hartford, CT 34 13 11 19 15 24 10 3
Houston-Sugar Land-Baytown, TX 44 55 42 58 35 28 18 18
Indianapolis-Carmel, IN 51 36 22 54 33 38 7 6
Jacksonville, FL 57 8 15 20 34 15 10 3
Kansas City, MO-KS 26 45 33 42 65 34 36 41
Las Vegas-Paradise, NV 12 10 4 8 12 7 0 0
Los Angeles-Long Beach-Santa Ana, CA 110 120 106 65 63 60 68 54
Louisville/Jefferson County, KY-IN 62 58 54 71 51 75 44 25
Memphis, TN-MS-AR 34 29 11 37 30 35 10 4
Miami-Fort Lauderdale-Pompano Beach, FL 5 4 11 4 11 10 5 2
Milwaukee-Waukesha-West Allis, WI 21 17 6 21 6 11 3 5
Minneapolis-St. Paul-Bloomington, MN-WI 5 15 11 11 1 5 1 2
Nashville-Davidson-Murfreesboro-Franklin, TN 36 20 7 26 17 34 9 1
New Orleans-Metairie-Kenner, LA 4 15 12 13 13 17 2 6
New York-Northern New Jersey-Long Island, NY-NJ-PA 63 39 39 47 42 39 29 11
Oklahoma City, OK 10 13 6 12 31 4 4 5
Orlando-Kissimmee, FL 5 4 5 8 8 8 1 0
Philadelphia-Camden-Wilmington, PA-NJ-DE-MD 97 77 38 59 53 45 29 7
Phoenix-Mesa-Scottsdale, AZ 22 26 9 23 25 11 11 6
Pittsburgh, PA 131 116 94 96 68 78 60 43
Portland-Vancouver-Beaverton, OR-WA 7 2 4 4 2 5 3 5
Providence-New Bedford-Fall River, RI-MA 38 18 10 20 15 14 4 1
Richmond, VA 46 19 12 29 17 24 17 1
Riverside-San Bernardino-Ontario, CA 177 160 148 141 128 135 124 110
Rochester, NY 16 5 0 0 1 5 2 0
Sacramento--Arden-Arcade--Roseville, CA 90 67 56 58 74 40 45 29
Salt Lake City, UT 33 21 36 26 20 27 17 16
San Antonio, TX 26 18 6 10 8 3 7 3
San Diego-Carlsbad-San Marcos, CA 35 41 27 26 39 33 35 25
San Francisco-Oakland-Fremont, CA 26 13 10 6 19 5 12 4
San Jose-Sunnyvale-Santa Clara, CA 24 14 7 4 13 3 13 6
Seattle-Tacoma-Bellevue, WA 13 10 4 6 10 9 7 8
St. Louis, MO-IL 89 68 34 79 29 41 21 9
Tampa-St. Petersburg-Clearwater, FL 81 69 38 30 21 31 10 6
Virginia Beach-Norfolk-Newport News, VA-NC 33 10 6 12 13 11 16 0
Washington-Arlington-Alexandria, DC-VA-MD-WV 58 29 25 40 32 37 16 4

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 U.S. Census Bureau's population estimates for July 1, 2000 and geographic definitions for 2000 available at http://www.census.gov/popest/metro/CBSA-est2009-annual.html as of Jul. 12, 2011. The U.S. Environmental Protection Agency reports data for metropolitan areas as they were defined in 2000.

SOURCES: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Trends, Air Quality Index Information, available at http://www.epa.gov/oaqps001/airtrends/aqi_info.html as of Jul. 12, 2011.