TUESDAY, Feb. 24, 2026 (HealthDay News) -- Prenatal lead exposure may be associated with later adulthood cognitive function, according to a study published online Feb. 18 in Neurology.
Ruby C. Hickman, Ph.D., from the Harvard T.H. Chan School of Public Health in Boston, and colleagues estimated associations between prenatal and early postnatal lead exposure and later adulthood cognitive function in the St. Louis Baby Tooth -- Later Life Health prospective cohort study. Participants donated their deciduous teeth between 1958 and 1972; in later adulthood, they completed surveys and a battery of cognitive tests.
Seven hundred fifteen participants had completed tooth metals analysis. The researchers observed a positive association between lead and performance on the vocabulary test, which was significantly different from the other tests. Performance on a composite of tests excluding vocabulary was 0.07 standard deviations (SD) lower for each part per million (ppm) higher second-trimester tooth dentin lead concentration. When coadjusting for third-trimester and postnatal lead, the effect was similar. The findings were driven by females, who had a significant 0.16 SD worse cognitive function in association with each 1 ppm higher second-trimester lead concentration; in the same model, this was equivalent to a three-year difference in age. The results were robust to adjustment for additional potential sources of confounding.
"Lead exposure in the United States peaked during the 1960s, '70s, and '80s, and children born during those years are now entering midlife and older adulthood, when these early-life exposures could have long-term effects on their cognitive health," Hickman said in a statement.