Daily Archives: August 31, 2015
By Aarian Marshall, http://www.citylab.com/
It’s killed some children slowly. It’s sent others into convulsions. But in Chicago, in the first decade of this century, a new study finds, the effects of childhood lead poisoning were more subtle—though perhaps equally as devastating. Research published in April by Environmental Health finds that even limited lead exposure in childhood is linked with dramatically lower third-grade test scores, in math as well as reading.
The researchers, mostly Chicago-based public health scientists, looked at a particularly large sample size of Chicago children—58,650—born in the Windy City between 1994 and 1998. First, they used a database of these children’s medical records, with a particular focus on the lead levels in their blood. Then the researchers compared those blood levels with those same students’ performances on third-grade standardized tests, taken in Chicago public schools between 2003 and 2006.
Even after adjusting for poverty, race, gender, and the education levels of each child’s mother, a strong link between lead in the blood and academic performance emerged: The presence of just 5 to 9 micrograms of lead per deciliter of blood (μg/dL, the standard measure for blood-lead levels) elevated the risk of failing math and reading standard tests by 32 percent. The researchers estimated that a full 13 percent of failing test numbers in reading and 14.8 percent of failing test numbers in math were due to the effects of lead. This is particularly notable because the Centers for Disease Control only recently halved the bolo levels required for medical intervention in children—from 10 μg/dL prior to 2012, to 5 μg/dL today.