A study by researchers at the University of Michigan links lead exposure in children to lower achievement on standardized tests.
It's published in the March issue of the American Journal of Public Health. Click here to read the study.
From the study:
Detroit has an extensive lead poisoning problem. Although only 20% of Michigan’s children younger than 5 years lived in Detroit in 2010, childhood lead poisoning in Detroit has consistently accounted for more than 50 percent of the state’s total lead burden.
Detroit Free Press reporter Keith Matheny's article explores the research further and the schools affected.
The greater the lead poisoning in a Detroit Public Schools student's blood, the higher the likelihood he or she will do poorly on achievement tests -- even after accounting for contributing factors such as poverty. That's the finding of a collaborative study that provides one of the most detailed assessments yet of the impact of lead poisoning on students' learning ability.
Children with lead at 2 to 5 micrograms per deciliter in their blood -- equal to or below stricter levels of concern set by the federal Centers for Disease Control and Prevention last year -- had a 33% higher likelihood of poor academic performance, said Harolyn Baker, a coauthor of the study and director of epidemiology at the nonprofit Michigan Healthcare Quality Improvement Organization.
Students with blood lead levels greater than 5 micrograms per deciliter have a 50% chance of doing poorly on MEAP tests, the study found.
As part of their coverage, the Detroit Free Press team also created an interactive map with a timeline going back to the 1990s. It helps illustrate the impacted areas throughout the city.
The map also overlays school locations. Several schools had student populations with close to half of the children with "troubling levels" of lead.
Michael Elliott, a Professor of Biostatistics at the University of Michigan and contributor to the study, said it’s long been known that very high blood lead levels can affect cognitive function.
“But to see this actually played out in test scores, and at some fairly low levels of lead exposure…was quite surprising, and quite distressing from a public health perspective,” Elliott said.
“I think this just adds to the evidence that lead has long-term effects that show up in the real world.”
Dr. Cynthia Aaron sees those “real world” implications of lead poisoning every day. She’s the medical director at the Regional Poison Center at the Children’s Hospital of Michigan.
There, Aaron and her staff work with children whose blood lead levels are extremely high—more than 40 miligrams per decileter.
Aaron wasn’t involved with the DPS study, but wasn’t surprised by the results.
“This is a pervasive problem in Detroit,” Aaron said. “And it’s a multi-factorial issue.”
The study teased out different factors known to impact student test scores—like race and socioeconomic status. It still found a strong link between lead blood lead levels and student performance.
But in the real world, “There’s no way to separate lead from all the other components” known to contribute to diminished academic performance, like poverty and sub-standard housing, Aaron said.
The Detroit Public Schools issued a statement in response to the study that didn’t directly address its results.
“Our principals are laser-focused on meeting the academic and educational needs of all of our students, regardless of the many societal, economic, family, behavioral, violence, as well as environmental factors that children face at home and in the community,” said Karen Ridgeway, Chief Academic and Accountability Officer for DPS. “That's how our schools were able to post record gains on those MEAP tests this year, surpassing statewide increases and closing the gaps.”
- Chris Zollars, Michigan Radio Newsroom