Low Level Lead Exposure Linked to Poor School Performance


Columbia, MD (August 20, 2012) –Today, NCHH released new findings on the impact of low-level lead exposure on school performance. The issue brief, “Childhood Lead Exposure and Educational Outcomes,” summarizes new research connecting small amounts of lead in a child’s blood to problems in school later in life.

In May of this year, the U.S. Centers for Disease Control and Prevention (CDC) updated its guidance on the level of lead in a child’s blood it considers harmful. Children with a blood lead level of 5 micrograms per deciliter (ug/dL) are considered by CDC to have more exposure to lead than 97.5% of their peers. This policy changed CDC’s long-standing guidance, which recommended action at 10 ug/dL.

The NCHH issue brief released today outlines evidence from a growing body of recent studies revealing the strong relationship between slightly elevated blood lead levels in young children and decreased test scores in elementary school and the contribution of childhood lead exposure to the widening achievement gap in the United States.

One of the studies summarized included more than 57,000 children and found that blood lead levels as low as 4 micrograms per deciliter at three years of age increase the likelihood that a child will be classified as learning disabled in elementary school.

Another study of 48,000 children found that children were at least 30% more likely to fail third grade reading and math tests if their blood lead level was over 5 µg/dL. Third grade test scores provide an important school success indicator, since low scores are highly correlated with high school dropout rates.

The evidence shows that children with higher blood lead levels are less likely to place into advanced and intellectually gifted programs. These results hold true even when considering factors such as race, family income, and others that might affect learning-disabled status.

Lead exposure accounts for important differences in educational achievement among racial and income groups. In a study of North Carolina school children tested for lead, three in four black children had a blood lead level above 3 µg/dL, compared to two in four white children.

“This should be a wake up call for our government agencies and educators—you can have extraordinary teachers, small classes, and first-rate curricula, but if your children come to school with a history of lead poisoning, they have the deck stacked against them,” said Rebecca Morley, executive director of the National Center for Healthy Housing.

 “The findings show the need for a long-term commitment to lead poisoning prevention from schools, parents, and all levels of government. Investing in the prevention of lead exposure will keep our schools and ultimately our country competitive,” said Anne Evens, Adjunct Professor at the University of Illinois-Chicago School of Public Health, and one of the researchers whose work was cited in the new brief. Download the full issue brief.

Funding support for the briefing paper was made possible through the American Public Health Association and the U.S. Centers for Disease Control and Prevention.

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