Measure E2: Daily Air Quality

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• The percentage of days that were designated as having “unhealthy” air quality (including days that were unhealthy for everyone as well as those that were unhealthy for sensitive groups) decreased between 1993 and 2006, dropping from 3.6 percent in 1993 to 2.6 percent in 2006. The percentage of days with “moderate” air quality was 12% in 1993 and 20% in 2006. Much of this increase is due to the adoption of a PM2.5 standard and implementation of widespread monitoring of PM2.5 in the late 1990s.
• The coverage of monitoring for this measure, in terms of area and percentage of days monitored, increased between 1993 and 2006. Approximately 24 percent of children’s days of exposure to air pollutants were not monitored in 2006. This percentage includes days for which no AQI was reported in counties where the AQI is sometimes reported, as well as counties in which the AQI is not reported at all. On days that were monitored, in many cases only one or a few pollutants were monitored.

Related Measures:

• Respiratory Illnesses