Has childhood exposure to lead in gasoline contributed to mental illness?

New research published in the Journal of Child Psychology and Psychiatry indicates that childhood lead exposure, which peaked from 1960 through 1990 in most industrialized countries due to the use of lead in gasoline, has negatively impacted mental health and likely caused many cases of mental illness and altered personality.

For the study, investigators combined blood–lead level data from National Health and Nutrition Examination Surveys with historic leaded gasoline data. (Leaded gas was phased out in United States by 1996.) They estimated US childhood blood–lead levels from 1940 to 2015 and assessed mental-health symptoms that have been linked to lead exposure.

Assuming that published associations of lead with illnesses are causal and not purely correlational, the team estimated that by 2015, there were 151 million excess mental disorders attributable to lead exposure. Lead-associated mental health and personality differences were most pronounced for people born from 1966 through 1986 (Generation X).

“Society frequently operates under the presumption that environmental exposures are safe until proven otherwise. Leaded gasoline wasn’t needed as an anti-knock agent-there were alternatives available. It was profitable.

An abundance of incontrovertible evidence occurring across decades was required to ban it,” said corresponding author Michael McFarland, PhD, of Florida State University. “By documenting the widespread consequences of exposure, this study underscores the folly of such thinking and highlights the long-lasting health consequences of exposure to the population.”

Reference:

Michael J. McFarland, Aaron Reuben, Matt Hauer, Contribution of childhood lead exposure to psychopathology in the US population over the past 75 years, Journal of Child Psychology and Psychiatry, https://doi.org/10.1111/jcpp.14072.