Estimated burden of blood lead levels 5 μg/dl in 1999–2002 and declines from 1988 to 1994

In light of recent data suggesting adverse health effects at blood lead levels (PbB) <10 μg/dl, lowering the current definition of elevated blood lead ( 10 μg/dl) has been recommended. To ascertain the population level impact of such a change, we calculated the prevalence of PbB 5 μg/dl in 1–21-year-old population in the United States. Furthermore, we characterized changes in PbB between 1988–1994 and 1999–2002. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) III (n=10,755) and NHANES 1999–2002 (n=8013). In 1999–2002, about 91.7% of study children had detectable levels of lead in the blood. Among them, 7.3%, 2.8%, and 1.0% children and adolescents aged 1–5, 6–11, and 12–21 years, respectively, had PbB between 5 and 9.9 μg/dl. This number translates to approximately 2.4 million individuals. Between 1988–1994 and 1999–2002, the geometric mean PbB declined from 2.88 to 1.94 μg/dl in children 1–5 years, 1.80 to 1.36 μg/dl in children 6–11 years, and 1.24–1.02 μg/dl in children and adolescents 12–21 years of age. Also, the prevalence of PbB 5 μg/dl declined from 25.7% to 8.8%, 12.8% to 3.0%, and 7.5% to 1.2% in these age groups, respectively. A substantial proportion of children may be at risk for adverse health effects from lead exposure below 10 μg/dl and a large number of children will be classified as having elevated PbB if 5 μg/dl is considered the threshold. Significant public health resources will have to be mobilized for intervention, screening, and case management of these children.