1-unit increase in lead associated with worse scores in math and reading for those with early childhood lead levels below 3.5 \u00b5g\/dL and \u22653.5 \u00b5g\/dL<\/p>\n<\/h3>\n
By Elana Gotkine HealthDay Reporter<\/b>
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WEDNESDAY, June 4, 2025 (HealthDay News) — A 1-unit increase in lead levels is associated with worse academic performance throughout school grades, according to a study published online May 28 in JAMA Network Open<\/em>.<\/p>\n George L. Wehby, M.P.H., Ph.D., from the University of Iowa in Iowa City, examined the association of a 1-unit change in early childhood blood lead levels below 3.5 \u00b5g\/dL versus \u22653.5 \u00b5g\/dL with academic achievement in a cohort study that linked birth certificates of children born from 1989 to 2010 with their math and reading test scores for grades 2 through 11 and to their early childhood blood lead testing data.<\/p>\n Up to 305,256 children and 1,782,873 child-grade observations were included in the analytical sample. Wehby found that at a mean child age at lead testing of 1.9 years, 37.7 percent of children had lead values below 3.5 \u00b5g\/dL. A 1-unit increase in lead levels below 3.5 \u00b5g\/dL was associated with lower national percentile rank (NPR) scores in math and reading (by \u22120.47 and \u22120.38, respectively). For lead levels \u22653.5 \u00b5g\/dL, a 1-unit increase was also associated with lower NPR scores in math and in reading (\u22120.52 and \u22120.56, respectively). Across grades 2 through 11, the declines in these scores were persistent.<\/p>\n “Reconsidering and potentially lowering current blood lead reference values for intervention may be needed to better address the associations of low-level lead exposures with cognitive and academic outcomes,” Wehby writes.<\/p>\n