America's Children: Key National Indicators of Well-Being, 2009
Lead in the Blood of Children
Lead is a major environmental health hazard for young children. Childhood exposure to lead contributes to learning problems and behavioral problems.66,67,68,69 A blood lead level of 10 micrograms per deciliter (µg/dL) or greater is considered elevated, but adverse health effects can occur at much lower concentrations.70,71 A child with a 10 µg/dL blood lead level will experience, on average, a decrease in IQ of 6 points.72 Lead exposures have declined since the 1970s, due largely to the removal of lead from gasoline and fewer homes with lead-based paint. However, 25 percent of U.S. homes have significant lead-based paint hazards, such as high lead levels in dust and soil, which may contribute to childhood exposure.73 Children ages 1–5 years are particularly vulnerable because they frequently engage in hand-to-mouth behavior.
Indicator PHY3.A: Percentage of children ages 1–5 with specified blood lead levels, selected years 1988–2006
* Estimate is unstable (relative standard error is greater than 30 percent but less than 40 percent).
SOURCE: National Center for Health Statistics, National Health and Nutrition Examination Survey.
- Children's blood lead levels in 2003–2006 were lower than in 1988–1994.
- In 2003–2006 about 21 percent of children ages 1–5 had blood lead levels greater than 2.5 µg/dL, and 4 percent had levels greater than 5 µg/dL. The estimate of children with levels greater than 10 µg/dL is a low percentage, and the available sample is too small to provide a statistically reliable estimate.
- About 12 percent of Black, non-Hispanic children and 2 percent of White, non-Hispanic children had blood lead levels at or above 5 µg/dL in 2003–2006.
- Children living in poverty generally had greater blood lead levels than children in families with incomes at or above the poverty line.
- The median blood lead concentration for children ages 1–5 dropped from about 14 µg/dL in 1976–1980 to about 2 µg/dL in 2003–2006.74
Indicator PHY3.B: Percentage of children ages 1–5 with specified blood lead levels by race and Hispanic origin75 and poverty status, 2003–2006
* Relative standard error is between 30 and 40 percent.
NOTE: Data for percentage of children with blood lead above 10 µg/dL are not shown because estimates by race and Hispanic origin and by poverty status are considered unreliable.
SOURCE: National Center for Health Statistics, National Health and Nutrition Examination Survey.
PHY3.A HTML Table, PHY3.B HTML Table
66 Bellinger, D., Leviton, A., Waternaux, C., Needleman, H., and Rabinowitz, M. (1987). Longitudinal analyses of prenatal and postnatal lead exposure and early cognitive development. New England Journal of Medicine, 316(17), 1037–1043.
67 Needleman, H.L., Schell, A., Bellinger, D., Leviton, A., and Allred, E.N. (1990). The long-term effects of exposure to low doses of lead in childhood: An 11-year follow-up report. New England Journal of Medicine, 322(2), 83–88.
68 Mendelsohn, A.L., Dreyer, B.P., Fierman, A.H., Rosen, C.M., Legano, L.A., Kruger, H.A., Lim, S.W., and Courtlandt, C.D. (1998). Low-level lead exposure and behavior in early childhood. Pediatrics, 101(3), E10.
69 Needleman, H.L., Riess, J.A., Tobin, M.J., Biesecker, G.E., and Greenhouse, J.B. (1996). Bone lead levels and delinquent behavior. Journal of the American Medical Association, 275(5), 363–369.
70 Centers for Disease Control and Prevention. (2002). Managing elevated blood lead levels among young children: Recommendations from the Advisory Committee on Childhood Lead Poisoning Prevention. Retrieved from http://www.cdc.gov/nceh/lead/CaseManagement/caseManage_main.htm.
71 Canfield, R.L., Henderson, C.R., Jr., Cory-Slechta, D.A., Cox, C., Jusko, T.A., and Lanphear, B.P. (2003). Intellectual impairment in children with blood lead concentrations below 10 micrograms per deciliter. New England Journal of Medicine, 348(16), 1517–1526.
72 Lanphear, B.P., Hornung, R., Khoury, J., Yolton, K., Baghurst, P., Bellinger, D.C., Canfield, R.L., Dietrich, K.N., Bornschein, R., Greene, T., Rothenberg, S.J., Needleman, H.L., Schnaas, L., Wasserman, G., Graziano, J., and Roberts, R. (2005). Low-level environmental lead exposure and children's intellectual function: An international pooled analysis. Environmental Health Perspectives, 113 (7), 894–899.
73 Jacobs, D.E., Clickner, R.P., Zhou, J.Y., Viet, S.M., Marker, D.A., Rogers, J.W., Zeldin, D.C., Broene, P., and Friedman, W. (2002). The prevalence of lead-based paint hazards in U.S. housing. Environmental Health Perspectives, 110 (10), A599–606.
74 U.S. Environmental Protection Agency. (2008). America's children and the environment. Measure B1: Lead in the blood of children, available at http://www.epa.gov/envirohealth/children/body_burdens/b1-graph.htm.
75 For 2003–2006, the revised 1997 OMB Standards for Data on Race and Ethnicity were used. Persons could select one or more of five racial groups: White, Black or African American, American Indian or Alaska Native, Asian, and Native Hawaiian or Other Pacific Islander. Included in the total but not shown separately are American Indian or Alaska Native, Asian, or Native Hawaiian or Other Pacific Islander due to the small sample size for each of these groups. Data on race and Hispanic origin are collected separately but combined for reporting. Persons of Mexican origin may be of any race. The National Health and Nutrition Examination Survey (NHANES) sample was designed to provide estimates specifically for persons of Mexican origin.