Nearly 1 in 4 Americans lives within three miles of a Superfund site.
Most of us know that’s not a good thing. Superfund sites—areas contaminated by hazardous waste and marked for clean-up by the Environmental Protection Agency—are associated with health risks, and houses close to the sites are often less valuable.
But we know less about just how environmental disasters and toxic pollution affect the development and educational outcomes of children, especially in the United States.
In “Inequality Before Birth: The Developmental Consequences of Environmental Toxins,” researchers from Northwestern University and the University of Florida’s pediatrics department matched birth and educational records to examine how exposure to various toxic chemicals before birth affected the educational and cognitive development of children.
The findings are disturbing if not surprising: Children who were conceived near a Superfund site before it was cleaned up are more likely to have a cognitive disability, to be suspended from school, to score lower on state tests, and to repeat a grade than children born to the same mothers in the same location after the hazardous waste had been cleaned.
Lead author Claudia Persico, a 2016 doctoral candidate at the Institute for Policy Research at Northwestern, studied the neurobiology of autism before she began her research in education and policy. As a researcher in neuroscience, she learned that some differences in the brains of those with autism started showing up in the first trimester of pregnancy.
So when she began learning about persistent achievement gaps between socioeconomic groups in education, and about the high portion of low-income and minority children diagnosed with cognitive disabilities, she wondered if some of those differences also began before birth.
“I started thinking about, what might pregnant women be exposed to in low-income communities that could cause brain changes in their developing children?” Persico said. Her first theory: Toxic waste.
So Persico used data from Florida’s health and education departments to explore the developmental trajectories of children conceived in zip codes near Superfund sites in that state between 1994 and 2002. In order to compare children from similar backgrounds, she focused on families that included multiple children conceived during different phases of Superfund clean-up — ie., one conceived before clean-up began and one after it ended. About 4,500 families who lived within 2 miles of a Superfund site had sibling pairs that fit this description; those families were more likely to be low-income than families in the state as a whole. Some 163,000 of the 1.6 million children born during this period who eventually enrolled in Florida public schools lived within 2 miles of a site.
Children who were conceived within two miles of a Superfund site before clean-up were 7.4 percentage points more likely to repeat a grade by the end of elementary school (About 25 percent, compared to 18.5 percent of those conceived after clean-up). The exposed siblings were also more than 6.6 percentage points more likely to have a serious behavioral incident (14.3 percent compared to 20.9 percent) and had slightly lower scores than their nonexposed siblings on standardized tests.
Those conceived within a mile of a Superfund site before cleanup were 10 percentage points more likely to be diagnosed with a cognitive disability such as a specific learning disability, autism, or speech and language impairment than children who weren’t as exposed.
The challenges faced by the older siblings who were exposed to the waste sites is striking because older siblings tend have stronger academic outcomes than younger siblings—a trend that held true in the data set for Florida children who were not exposed to Superfund sites.
The paper suggests that exposure to toxic chemicals may help explain some persistent academic, behavioral, and development gaps between lower- and higher-income children and between minority and White children. “It’s an environmental justice issue,” Persico said. “It’s not random where these sites are; they tend to lower housing values, so children who live nearby are more likely to be low-income.”
She said the findings could also help schools near Superfund sites understand their students’ needs. Since educating children with developmental disabilities tends to be expensive, Persico said, “these are huge costs being borne by the school districts... that may have origins in local industry.”
Persico said that the evidence that children conceived after the sites were cleaned up had better outcomes makes a case for continuing to support the cleanup of Superfund sites. “Yes, these are really expensive to clean up,” she said. “But if you don’t think about the impact on children and children’s cognitive development, you’re missing some of the really expensive cost of pollution.”
The EPA provides a map of Superfund sites: //toxmap-classic.nlm.nih.gov/
Image source: Screenshot from National Institutes of Health’s Toxmap website.
A version of this news article first appeared in the Inside School Research blog.