America's Children: Key National Indicators of Well-Being, 2009
Outdoor and Indoor Air Quality
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.49 These standards, established by the U.S. Environmental Protection Agency under the Clean Air Act, are designed to protect public health, including the health of susceptible populations such as children and individuals with asthma. Ozone, particulate matter, sulfur dioxide, and nitrogen dioxide are air pollutants associated with increased asthma episodes and other respiratory illnesses.50,51,52,53 Lead can affect the development of the central nervous system in young children,54 and exposure to carbon monoxide can reduce the capacity of blood to carry oxygen.55
Indicator PHY1.A: Percentage of children ages 0–17 living in counties in which levels of one or more air pollutants were above allowable levels, 1999–2007
NOTE: The U.S. Environmental Protection Agency has set national air quality standards for six principal pollutants: carbon monoxide (CO), lead (Pb), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM10 and PM2.5), and sulfur dioxide (SO2). Nitrogen dioxide and sulfur dioxide are not included in the graph because all areas meet the Primary National Ambient Air Quality Standards for these pollutants. This analysis incorporates a new Primary National Ambient Air Quality Standard for ozone that was promulgated in 2008.
SOURCE: U.S. Environmental Protection Agency, Office of Air and Radiation, Air Quality System.
- In 2007, 66 percent of children lived in counties in which one or more air pollutants were above allowable levels.
- Ozone is the pollutant that is most often above the allowable levels as defined by the Primary National Ambient Air Quality Standards. Ozone, as well as particulate matter, can cause respiratory problems and aggravate respiratory diseases, such as asthma, in children.50,52,53 These problems can lead to increased emergency room visits and hospitalizations.56,57,58,59 In 2007, 64 percent of children lived in counties in which ozone concentrations were above allowable levels.
- In 2007, approximately 16 percent of children lived in counties where levels of fine particulate matter (PM2.5) were above the annual allowable standard, compared with 24 percent in 1999. The term "particulate matter" (PM) includes both solid particles and liquid droplets found in air.53 Airborne particles measuring less than 10 micrometers in diameter (PM10) pose a health concern because they can be inhaled into and accumulate in the respiratory system. Particles less than 2.5 micrometers in diameter (PM2.5) are referred to as "fine" particles and are believed to pose the largest health risks because they can lodge deeply in the lungs.
Children who are exposed to environmental tobacco smoke, also known as secondhand smoke, have an increased probability of experiencing such adverse health effects as infections of the lower respiratory tract, bronchitis, pneumonia, middle ear disease, sudden infant death syndrome (SIDS), and respiratory symptoms.60 Secondhand smoke can also play a role in the development and exacerbation of asthma.60 The U.S. Surgeon General has determined that there is no risk-free level of exposure to secondhand smoke.60 Cotinine, a breakdown product of nicotine, is a marker for recent (previous 1–2 days) exposure to secondhand smoke.
Indicator PHY1.b: Percentage of children ages 4–11 with specified blood cotinine levels, selected years 1988–2006
NOTE: "Any detectable cotinine" indicates blood cotinine levels at or above 0.05 nanograms per milliliter (ng/mL), the detectable level of cotinine in the blood in 1988–1994. Cotinine levels are reported for nonsmoking children only. The average (geometric mean) blood cotinine level in children living in homes where someone smoked was 1.0 ng/mL in 1988–1994.
SOURCE: National Center for Health Statistics, National Health and Nutrition Examination Survey.
Indicator PHY1.C: Percentage of children ages 0–6 living in homes where someone smoked regularly by poverty status, 1994 and 2005
SOURCE: National Center for Health Statistics, National Health Interview Survey.
- The percentage of children ages 4–11 with detectable blood cotinine levels decreased from 88 percent in 1988–1994 to 51 percent in 2005–2006. In 2005–2006, 12 percent had blood cotinine levels more than 1.0 nanograms per milliliter (ng/mL), down from 26 percent in 1988–1994.
- In 2005, the percentage of children ages 0–6 living in homes where someone smoked regularly was 8 percent, compared with 27 percent in 1994.61 Children living below the poverty level and Black, non-Hispanic children were more likely than their peers to be living in homes where someone smoked regularly.
PHY1.A HTML Table, PHY1.B HTML Table, PHY1.C HTML Table
49 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.
50 U.S. Environmental Protection Agency. (1994). Supplement to the second addendum (1986) to air quality criteria for particulate matter and sulfur oxides (1982): Assessment of new findings on sulfur dioxide acute exposure health effects in asthmatic individuals (EPA/600/FP-93/002). Research Triangle Park, NC: Author.
51 U.S. Environmental Protection Agency. (2008). Science Assessment for Oxides of Nitrogen—Health Criteria (EPA/600/R-08/071). Research Triangle Park, NC: Author.
52 U.S. Environmental Protection Agency. (2006). Air quality criteria for ozone and related photochemical oxidants (EPA/600/R-05/004aF). Research Triangle Park, NC: Author.
53 U.S. Environmental Protection Agency. (2004). Air quality criteria for particulate matter (EPA/600/P-99/002aF, EPA/600/P-99/002bF). Research Triangle Park, NC: Author.
54 U.S. Environmental Protection Agency. (2006). Air quality criteria for lead: Volume I (EPA/600/R-05/144aF). Research Triangle Park, NC: Author.
55 U.S. Environmental Protection Agency. (2000). Air quality criteria for carbon monoxide (EPA 600/P-99/001F). Research Triangle Park, NC: Author.
56 Burnett R.T., Cakmak, S., Brook, J.R., and Krewski, D. (1997). The role of particulate size and chemistry in the association between summertime ambient air pollution and hospitalization for cardiorespiratory diseases. Environmental Health Perspectives, 105(6), 614–620.
57 Burnett, R.T., Smith-Doiron, M., Stieb, D., Cakmak, S., and Brook, J.R. (1999). Effects of particulate and gaseous air pollution on cardiorespiratory hospitalizations. Archives of Environmental Health, 54 (2), 130–139.
58 Gwynn, R.C., Burnett, R.T., and Thurston, G.D. (2000). A time-series analysis of acidic particulate matter and daily mortality and morbidity in the Buffalo, New York, region. Environmental Health Perspectives, 108 (2), 125–133.
59 Thurston, G., Kazuhiko, I., Hayes, C., Bates, D., and Lippmann, M. (1994). Respiratory hospital admissions and summertime haze air pollution in Toronto, Ontario: Consideration of the role of acidic aerosols. Journal of Exposure Analysis and Environmental Epidemiology, 2, 429–450.
60 U.S. Department of Health and Human Services. (2006). The health consequences of involuntary exposure to tobacco smoke: A report of the Surgeon General. Atlanta, GA: Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health.
61 Regular smoking is defined as smoking by a resident that occurs 4 or more days per week.