The hidden cost of lead exposure on American mental health

The harm that lead exposure can do to people's health is long-established. A recently published study has revealed just how much harm childhood lead exposure can cause and how such lead exposure drove a hidden mental health crisis of which many Americans living today have likely been victims.

Lead is 'even more dangerous to humanity than we knew'

The toxic metal lead has "cast a long shadow on our collective well-being," said Gizmodo. A new study published in The Journal of Child Psychology and Psychiatry revealed that lead exposure during the 20th century "significantly worsened Americans' brain health, likely helping cause many more cases of mental illness that otherwise would have never happened."

Researchers at Duke University and Florida State University built on their past studies of the impact of lead on our health. They estimated that childhood lead exposure during the decades lead was found in most gasoline, "directly contributed to 151 million more cases of psychiatric disorder among Americans over the past 75 years." The findings indicate that lead has been "even more dangerous to humanity than we knew."

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Car manufacturers began to add lead to gasoline in the 1920s to reduce "wear and tear on the engines." This led to leaded gasoline becoming America's "single largest source of lead exposure, reaching a peak during the 1960s." Heavy lead exposure has long been known to be detrimental to our health. It then became "firmly established by the 1970s that even small amounts of lead could be harmful, especially to the brains of developing children." Lead was not phased out of gasoline until 1996 in the U.S. and 2020 globally.

The university teams' earlier research in 2022 calculated that about half of all Americans alive in 2015 were likely exposed to damaging levels of lead in their childhood, based on population survey data and known levels of leaded gasoline use in the country. The latest study estimates that about 151 million mental disorder diagnoses in the U.S. are attributable to lead exposure. The most significant lead-related diagnoses featured symptoms of anxiety, depression and ADHD. "Childhood lead exposure has likely made a significant, underappreciated contribution to psychiatric disease in the United States over the past century," the researchers said in their paper.

'We've got to stop putting this burden on people and families'

"I think we need to move away from using lead," Aaron Reuben, assistant professor of Clinical Neuropsychology at the University of Virginia and one of the studies authors, said to Newsweek. The more we know about lead, "the more we understand that the costs of using it — to children, families and society — are always greater than the benefits." Lead is still used in various products, including "bronze, bullets, many types of paint, airplane fuel and car batteries," he said. "It's time to end that."

Institutions need to invest in research and the elimination of lead from the environment, Bruce Lanphear, a population health scientist at Simon Fraser University in Canada with expertise in lead poisoning, said to CNN. Regulatory agencies like the FDA need to take steps to ensure "there's no lead in the baby food," he said. Finding ways to deal with the "20 million homes that still contain lead hazards, getting rid of leaded aviation fuel, these are not things that people can do," he added. "We've got to stop putting this burden on people and families."

There are "undoubtedly many people still alive today who have suffered from lead-caused mental illness that wouldn't have occurred in a better world," Gizmodo said. While the "worst of lead's harms may be over," its impact will "loom large for a long time."