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One of the many concerns in Flint, Mich., is how lead exposure affects children. Research out today suggests children exposed to toxic lead feel the effects throughout their lives. As NPR's Rae Ellen Bichell reports, the study shows a link between childhood lead exposure and a dip decades later in a person's cognitive ability and socioeconomic status.
RAE ELLEN BICHELL, BYLINE: Lead can come from lots of places - from old paint, contaminated soil, from water that's passed through lead pipes. And Aaron Reuben says when that lead gets into a human body, it can mess with brain development.
AARON REUBEN: It's toxic to many parts of the body but in particular can accumulate in the bloodstream and pass through the blood-brain barrier to reach the brain.
BICHELL: Reuben is a graduate student in clinical psychology at Duke University. He and his colleagues just published the results of a big study on how lead exposure as a child can impact a person's life as an adult. The results are based on about 560 people. Researchers had kept in touch with them for decades from when they were born in Dunedin, New Zealand, in the 1970s until now.
When the people were children, researchers checked their blood for lead and gave them an IQ test. Then when they turned 38 years old, they got another IQ test. As Reuben and his colleagues wrote in the journal JAMA, they found a subtle but worrisome pattern. People who had low lead exposure as children had either the same or slightly higher IQ than they'd had as kids, but, Reuben says...
REUBEN: People who experienced higher lead exposures over time saw their intellectual abilities decline from their sort of baseline starting point, and people who saw that decline also experienced downward social mobility.
BICHELL: In other words, lead exposure seemed to continue to harm these people for decades after their childhoods. Reuben says the trends in IQ and socioeconomic status were mild, but...
REUBEN: Even small changes in IQ had some significant influence on the course that people's lives took.
BICHELL: In the U.S., it's been years since policies went into place limiting or eliminating lead in paint, plumbing and gasoline. But there's still a lot of legacy lead hanging around which kids can still ingest. And unlike in New Zealand where lead exposure appears to have impacted all socioeconomic groups, in this country, it's children living in low-income areas that tend to be most at risk.
REUBEN: Most of these kids are starting out already disadvantaged in life.
BICHELL: And he says this study shows exposure to lead may be one more thing holding them back for decades to come. Rae Ellen Bichell, NPR News.
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