Lead exposure, even in very low amounts, has a negative effect on young children taking school tests, according to a new study by researchers at UW-Madison and the Wisconsin Department of Health Services.
Researchers found fourth graders who had tested positive for lead exposure performed worse than other fourth graders on the Wisconsin Knowledge and Concepts Exam (WKCE), which measures competence in reading, math and other basic subjects.
The study was published in the journal Annals of Epidemiology, the UW-Madison news bureau said in a news release.
The study found that environmental lead exposure, usually occurring from contaminated lead dust and soil around older homes, poses a significant challenge to schools striving to meet WKCE standards.
Researchers matched medical records of children who had been tested for lead exposure with their school records.
"Even after controlling for differences in test scores due to poverty, gender, English proficiency and other factors, children who had been exposed to lead scored lower on each subject of the fourth grade WKCE," the release said.
The study also found lead exposure rates in African-American and Hispanic children were double that of white children.
Marty Kanarek, a professor of population health sciences at UW-Madison, said lead exposure in children is a matter of social justice.
"Students exposed to lead are at a considerable disadvantage the first day they show up in school," Kanarek said in the release. "The fact African-American and Hispanic students were twice as likely as white students to be exposed (to lead) suggests part of the racial achievement gap may be directly due to lead in the environment."
"If that's true, then educational reforms alone will not eliminate the problem," Kanarek said. "We need to clean up contaminated housing."