A new study led by Jianghong Liu from University of Pennsylvania and involving preschool children in China reveals that elevated levels of lead in children's blood may be linked with increased behavioral problems.
Background: Lead toxicity can lower a child's IQ. Blood lead concentrations greater than 10 μg/dL also have been linked to behavior problems in children. Still, the effect of lead on children's behavior is less understood than its effect on IQ. Lead exposure is a problem in developing countries where children have higher blood lead levels than in the United States or Europe. The authors examined the association between more moderately elevated blood lead concentrations (average 6.4 μg/dL) and behavioral problems.
How the Study Was Conducted: The authors used data from a sample of preschoolers in China, which included 1,341 children for whom blood lead level concentrations were available (measured at age 3-5). Behavioral problems were assessed using the Chinese version of the Child Behavior Checklist and Caregiver-Teacher Report Form when children were 6 years old.
Results: Children in the sample had an average blood lead concentration of 6.4 μg/dL. The authors found associations between blood lead levels and teacher-reported behavioral problems at 6 years of age. The authors note because they only measured blood lead concentrations once in children at ages 3 to 5 years it is unclear whether the problems seen at age 6 reflect lead exposure at the time of measurement, during the prenatal period or during the first two years of life.
Conclusion: "Further examination is needed to more clearly delineate the biological effects of environmental lead exposure and resulting behavioral impairments among children and to assess the long-term clinical significance of these findings."