PHY1.A Outdoor air quality: Percentage of children ages 0–17 living in counties in which levels of one or more air pollutants were above allowable levels, 1999

Characteristic	1999	2000	2001	2002	2003	2004	2005	2006	2007	2008
One or more pollutants	67.57	69.12	69.30	67.52	69.78	63.92	69.68	66.33	65.40	59.82
Pollutant
Ozone	65.24	64.93	66.27	66.17	67.88	61.68	66.36	65.47	64.24	59.19
Carbon monoxide	5.68	4.38	0.98	4.10	1.03	0.07	0.61	0.49	0.11	0.21
Particulate matter (PM10)	7.93	6.26	6.01	4.83	7.87	5.16	5.00	5.02	12.53	4.47
Particulate matter (PM2.5)	24.16	29.62	24.73	20.95	19.13	16.51	24.43	12.48	16.20	7.31
Lead	2.26	1.60	2.15	1.22	1.59	1.19	1.61	1.21	1.50	1.53
Nitrogen dioxide	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
Sulfur dioxide	0.30	0.21	0.00	0.04	0.00	0.00	0.00	0.00	0.00	0.05
NOTE: Percentages are based on the number of children living in counties where air pollution levels were higher than a Primary National Ambient Air Quality Standard. This analysis differs from the analysis utilized by the U.S. Environmental Protection Agency for the designation of “nonattainment areas” for regulatory compliance purposes. Data have been revised since previous publication in America's Children. Values have been recalculated based on updated data in the Air Quality System. This analysis incorporates a revised Primary National Ambient Air Quality Standard for lead that was promulgated in 2008. For more information on the air quality standards that are used in calculating these percentages, please see http://www.epa.gov/air/criteria.html.
SOURCE: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Quality System.