Study Looks at Impact of Children”s Exposure to Lead in the United States

WEDNESDAY, Dec. 4, 2024 (HealthDay News) — Children”s exposure to lead in the United States has had a significant impact on mental illness symptomatology and disadvantageous personality differences, according to a study published online Dec. 4 in the Journal of Child Psychology and Psychiatry.

Michael J. McFarland, Ph.D., from Florida State University in Tallahassee, and colleagues combined serial, cross-sectional blood-lead level (BLL) data from National Health and Nutrition Examination Surveys with historic leaded-gasoline data to estimate U.S. childhood BLLs from 1940 to 2015. Population mental health symptom elevations from known lead-psychopathology associations were calculated.

Assuming the published lead-psychopathology associations are causal, the researchers estimated that the U.S. population gained 602 million General Psychopathology factor points arising from leaded gasoline by 2015, reflecting an increase of 0.13 standard deviations in overall liability to mental illness and an estimated 151 million excess mental disorders due to exposure to lead. Standard deviation increases of 0.64 and 0.42 in population-level internalizing symptoms and attention-deficit/hyperactivity disorder symptoms, respectively, were identified on examination of specific disorder-domain symptoms. A 0.14-standard deviation increase in population-level neuroticism was seen, as was a 0.20-standard deviation decrease in conscientiousness. Cohorts born from 1966 to 1986 had the most pronounced lead-associated mental health and personality differences.

“A significant burden of mental illness symptomatology and disadvantageous personality differences can be attributable to U.S. children’s exposure to lead over the past century,” the authors write. “The contribution of legacy lead exposures to population health and disease may be much larger than previously assumed.”

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