The environment in which children live plays an important role in their health and development. Children may be more vulnerable than adults to the adverse effects of environmental contaminants in air, food, drinking water, and other sources because their bodies are still developing. In addition, children have increased potential for exposure to pollutants because they eat, drink, and breathe more, in proportion to the size of their bodies, than adults. One important measure of children's environmental health is the percentage of children living in areas in which air pollution levels are higher than the allowable levels of the Primary National Ambient Air Quality Standards.48 These standards, established by the Environmental Protection Agency (EPA) under the Clean Air Act, are designed to protect public health, including the health of susceptible populations such as children. Ozone, particulate matter, sulfur dioxide, and nitrogen dioxide are air pollutants associated with increased asthma episodes and other respiratory illnesses in children. These problems can lead to increased emergency room visits and hospitalizations.49, 50, 51, 52 Lead can affect the development of the central nervous system in young children,53 and exposure to carbon monoxide can reduce the capacity of blood to carry oxygen.54
NOTE: Percentages are based on the number of children living in counties where measured air pollution concentrations were higher than the level of a Primary National Ambient Air Quality Standard at least once during the year. The Environmental Protection Agency (EPA) periodically reviews air quality standards and may change them based on updated scientific findings. The indicator is calculated with reference to the current levels of the air quality standards for all years shown, except that the revision to the PM2.5 annual standard promulgated in December 2012 has not been incorporated into this analysis. Measuring concentrations above the level of a standard is not equivalent to violating the standard. The level of a standard may be exceeded on multiple days before the exceedance is considered a violation of the standard. Data have been revised since previous publication in America's Children. Values have been recalculated based on updated Census population data and updated data in the Air Quality System. 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: Environmental Protection Agency, Office of Air and Radiation, Air Quality System.
48 This measure does not differentiate between counties in which the Primary National Ambient Air Quality Standards are exceeded frequently or by a large margin and counties in which the standards are exceeded only rarely or by a small margin. It must also be noted that this analysis differs from the analysis utilized by the U.S. Environmental Protection Agency for the designation of "nonattainment areas" for regulatory compliance purposes.
49 U.S. Environmental Protection Agency. (2008). Integrated science assessment for sulfur oxides—Health criteria (Final report) (EPA/600/R-08/047F). Washington, DC: U.S. EPA, National Center for Environmental Assessment. Retrieved from http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=198843.
50 U.S. Environmental Protection Agency. (2008). Integrated science assessment for oxides of nitrogen—Health criteria (EPA/600/R-08/071). Research Triangle Park, NC: Author.
51 U.S. Environmental Protection Agency. (2013). Integrated science assessment of ozone and related photochemical oxidants (Final report) (EPA/600/R-10/076F). Washington, DC: U.S. EPA. Retrieved from http://cfpub.epa.gov/ncea/isa/recordisplay.cfm?deid=247492.
52 U.S. Environmental Protection Agency. (2009). Integrated science assessment for particulate matter (Final report) (EPA/600/R-08/139F). Washington, DC: U.S. EPA, National Center for Environmental Assessment. Retrieved from http://cfpub.epa.gov/ncea/CFM/recordisplay.cfm?deid=216546.
53 U.S. Environmental Protection Agency. (2006). Air quality criteria for lead: Volume I (EPA/600/R-05/144aF). Research Triangle Park, NC: Author.
54 U.S. Environmental Protection Agency. (2010). Integrated science assessment for carbon monoxide (Final report) (EPA/600/R-09/019F). Washington, DC: U.S. EPA, National Center for Environmental Assessment. Retrieved from http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=218686.