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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

Table Version | Excel

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

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