The Environmental Protection Agency (EPA) cracked down on lead-based products—including lead paint and leaded gasoline—in the 1970s because of its toxic effects on human health. Scientists at the University of Utah have analyzed human hair samples spanning nearly 100 years and found a 100-fold decrease in lead concentrations, concluding that this regulatory action was highly effective in achieving its stated objectives. They described their findings in a new paper published in the Proceedings of the National Academy of Sciences.
We’ve known about the dangers of lead exposure for a very long time—arguably since the second century BCE—so why conduct this research now? Per the authors, it’s because there are growing concerns over the Trump administration’s move last year to deregulate many key elements of the EPA’s mission. Lead specifically has not yet been deregulated, but there are hints that there could be a loosening of enforcement of the 2024 Lead and Cooper rule requiring water systems to replace old lead pipes.
“We should not forget the lessons of history. And the lesson is those regulations have been very important,” said co-author Thure Cerling. “Sometimes they seem onerous and mean that industry can’t do exactly what they’d like to do when they want to do it or as quickly as they want to do it. But it’s had really, really positive effects.”
An American mechanical and chemical engineer named Thomas Midgley Jr. was a key player in the development of leaded gasoline (tetraethyl lead) because it was an excellent anti-knock agent, as well as the first chlorofluorocarbons (CFCs) like freon. Midgley publicly defended the safety of tetraethyl lead (TEL), despite experiencing lead poisoning firsthand. He held a 1924 press conference during which he poured TEL on his hand and inhaled TEL vapor for 60 seconds, claiming no ill effects. It was probably just a coincidence that he later took a leave of absence from work because of lead poisoning. (Midgley’s life ended in tragedy: he was severely disabled by polio in 1940 and devised an elaborate rope-and-pulley system to get in and out of bed. That system ended up strangling him to death in 1944, and the coroner ruled it suicide.)