“Researchers used blood-lead level, census and leaded gasoline consumption data to examine how widespread early childhood lead exposure was in the country between 1940 and 2015. … 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.” Half of US adults exposed to harmful lead levels as kids. (I’d have an insightful take here if I hadn’t been born into an era where we were basically huffing lead.)