America's Children: Key National Indicators of Well-Being, 2011
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.67 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.72 Children ages 1–5 are particularly vulnerable because they frequently engage in hand-to-mouth behavior.
Indicator Phys4.A: Percentage of children ages 1–5 with specified blood lead levels, 1988–1994, 1999–2002, and 2005–2008
SOURCE: National Center for Health Statistics, National Health and Nutrition Examination Survey.
Indicator Phys4.B: Percentage of children ages 1–5 with specified blood lead levels by race and Hispanic origin74 and poverty status, 2005–2008
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.
- Children's blood lead levels in 2005–2008 were lower than in 1988–1994.
- In 2005–2008, about 16 percent of children ages 1–5 had blood lead levels greater than 2.5 µg/dL, and 3 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 32 percent of Black, non-Hispanic children, 16 percent of Mexican American children, and 12 percent of White, non-Hispanic children had blood lead levels at or above 2.5 µg/dL in 2005–2008.
- 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 15 µg/dL in 1976–1980 to about 1 µg/dL in 2005–2008.73
PHY4.A HTML Table, PHY4.B HTML Table
66 Surkan, P.J., Zhang, A., Trachtenberg, F., Daniel, D.B., McKinlay, S., and Bellinger, D.C. (2007). Neuropsychological function in children with blood lead levels <10 microg/dL. Neurotoxicology, 28 (6), 1170–7.
67 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.
68 Chiodo, L.M., Covington, C., Sokol, R.J., Hannigan, J.H., Jannise, J., Ager, J., Greenwald, M., and Delaney-Black, V. (2007). Blood lead levels and specific attention effects in young children. Neurotoxicology and Teratology, 29, 538–546.
69 Nigg, J.T., Nikolas, M., Mark Knottnerus, G., Cavanagh, K., and Friderici, K. (2010). Confirmation and extension of association of blood lead with attention-deficit/hyperactivity disorder (ADHD) and ADHD symptom domains at population-typical exposure levels. The Journal of Child Psychology and Psychiatry, 51 (1), 58–65.
70 Centers for Disease Control and Prevention. (2005). Preventing lead poisoning in young children. Atlanta, GA. Author.
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 Jacobs, D.E., Clickner, R.P., Zhou, J.Y., Viet, S.M., Marker, D.A., Rogers, J.W., Friedman, W. (2002). The prevalence of lead-based paint hazards in U.S. housing. Environmental Health Perspectives, 110 (10), A599–606.
73 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.html.
74 For 2005–2008, the revised 1997 Office of Management and Budget (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, Native Hawaiian or Other Pacific Islander, and "Two or more races." Data on race and Hispanic origin are collected separately but combined for reporting. Persons of Mexican origin may be of any race.