The scientists from Florida State University and Duke University found that 90% of children born in the U.S. between 1950 and 1981 had blood-lead levels higher than the CDC threshold. And the researchers found significant impact on cognitive development: on average, early childhood exposure to lead resulted in a 2.6-point drop in IQ.
Over 170 million U.S.-born people who were adults in 2015 were exposed to harmful levels of lead as children, a new study estimates. Researchers used blood-l.