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FIGURE 8-16 Number of Days with Air Quality Index > 100 Monitoring Sites in U.S. Urban Areas: 1990-2010

Friday, April 10, 2015

Graphic Version | Excel

  1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
California before 1999 1,099 1,076 1,031 892 931 912 830 666 637                        
Rest of U.S. before 1999 2,992 3,138 2,437 2,764 2,604 2,594 2,145 2,157 2,779                        
California 1999-2010                   884 836 896 901 808 647 567 612 541 571 461 346
Rest of U.S. 1999-2010                   2,916 2,132 2,243 2,481 1,692 1,239 1,973 1,451 1,567 934 427 666

NOTE: 1999 was the first year PM2.5 was included in the AQI.

SOURCE: U.S. Environmental Protection Agency, Number of Days with Air Quality Index Values Greater than 100 at Trend Sites, 1990-2010, and All Sites in 2010. Air Quality Index Information. Available at http://www.epa.gov/airtrends/aqi_info.html as of October 2013