Low levels of lead linked to lower test scores in children

Small doses of lead may have big impacts on reading and math scores, scientists report April 7 in Environmental Health.

Researchers looked at third grade test scores and levels of lead in blood samples from 58,650 students in Chicago public schools. As little as 2 micrograms of lead per deciliter of blood was associated with lower reading and math scores. The Centers for Disease Control and Prevention recommends that anything above 5 micrograms per deciliter is of concern.

The researchers estimate that childhood lead levels at or above 5 micrograms per deciliter of blood accounted for as many as 25 percent of the children in the study failing reading and math standardized tests. The findings confirm that lead exposure, even at low doses, is associated with poor school performance.