Trends in blood lead levels and blood lead testing among US children aged 1 to 5 years, 1988-2004

Abstract

Objectives: To evaluate trends in children's blood lead levels and the extent of blood lead testing of children at risk for lead poisoning from national surveys conducted during a 16-year period in the United States.

Methods: Data for children aged 1 to 5 years from the National Health and Nutrition Examination Survey III Phase I, 1988-1991, and Phase II, 1991-1994 were compared to data from the survey period 1999-2004.

Results: The prevalence of elevated blood lead levels, >/=10 microg/dL, among children decreased from 8.6% in 1988-1991 to 1.4% in 1999-2004, which is an 84% decline. From 1988-1991 and 1999-2004, children's geometric mean blood lead levels declined in non-Hispanic black (5.2-2.8 microg/dL), Mexican American (3.9-1.9 microg/dL), and non-Hispanic white children (3.1 microg/dL to 1.7 microg/dL). However, levels continue to be highest among non-Hispanic black children relative to Mexican American and non-Hispanic white children. Blood lead levels were distributed as follows: 14.0% were <1.0 microg/dL, 55.0% were 1.0 to <2.5 microg/dL, 23.6% were 2.5 to <5 microg/dL, 4.5% were 5 to <7.5 microg/dL, 1.5% were 7.5 to <10 microg/dL, and 1.4% were >/=10 microg/dL. Multivariable analysis indicated that residence in older housing, poverty, age, and being non-Hispanic black are still major risk factors for higher lead levels. Blood lead testing of Medicaid-enrolled children increased to 41.9% from 19.2% in 1988-1991. Only 43.0% of children with elevated blood lead levels had previously been tested.

Conclusions: Children's blood lead levels continue to decline in the United States, even in historically high-risk groups for lead poisoning. To maintain progress made and eliminate remaining disparities, efforts must continue to test children at high risk for lead poisoning, and identify and control sources of lead. Coordinated prevention strategies at national, state, and local levels will help achieve the goal of elimination of elevated blood lead levels.