Banning lead in gas worked. The proof is in our hair Researchers analyzed samples of Utahns' hair going back a century to document a 100-fold decrease in lead concentrations.
Prior to the establishment of the Environmental Protection Agency in 1970, Americans lived in communities awash with lead from industrial sources, paint, water supply pipes and, most significantly, tailpipe emissions. A dangerous neurotoxin that accumulates in human tissues and is linked to developmental deficits in children, environmental lead levels have come way down in the years since, and so have human exposures.
The proof is in your hair.
An analysis of hair samples conducted by University of Utah scientists shows precipitous reductions in lead levels since 1916.
“We were able to show through our hair samples what the lead concentrations are before and after the establishment of regulations by the EPA,” said demographer Ken Smith, a distinguished professor emeritus of family and consumer studies. “We have hair samples spanning about 100 years. And back when the regulations were absent, the lead levels were about 100 times higher than they are after the regulations.”
A useful element with a dark side
The findings, which appear in PNAS, underscore the vital role of environmental regulations in protecting public health. The study notes lead rules are now being weakened by the Trump administration in a wide-ranging move to ease environmental protections.
“We should not forget the lessons of history. And the lesson is those regulations have been very important,” said co-author Thure Cerling, a distinguished professor of both geology and biology. “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.”
Lead is the heaviest of heavy metals that, like mercury and arsenic, accumulate in living tissue and are toxic at even low levels. Yet lead holds very useful properties, great for fashioning into pipes and as a chemical additive. Lead was added to paint to improve durability, speed up drying, and produce vibrant colors with greater coverage. Lead also improved the performance of automobile engines by preventing pistons from “knocking.”
By the 1970s, its toxicity became well established, and EPA regulations began phasing it out of paint, pipes, gasoline and other consumer products.
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