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 estimate that half of the U.S. adult population at that time had been exposed to levels of lead that surpass five micrograms per deciliter, the Centers for Disease Control and Prevention threshold for lead exposure. They also 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 the impact on cognitive development was significant: on average, early childhood exposure to lead resulted in a 2.6-point drop in IQ.
Half of US adults exposed to harmful lead levels as kids
