Prenatal lead exposure associated with worse cognitive function in adulthood
Early-in-life exposure to lead was linked with worse cognitive function in late adulthood among women, according to a new study led by Harvard T.H. Chan School of Public Health.
The study was published Feb. 18 in Neurology and was led by Ruby Hickman, PhD ’25, when she was a doctoral researcher in the Weisskopf Lab. She and her colleagues conducted the study as part of the lab’s St. Louis Baby Tooth—Later Life Health Study (SLBT), a research program that uses baby teeth, donated to science between 1958 and 1972, to investigate the long-term health impacts of early-life environmental exposures.
Lead exposure’s neurocognitive impacts in childhood have been well studied; their long-term impacts into adulthood remain less investigated. The researchers recruited 715 SLBT participants—mostly women, with an average age of 62—to help them fill this gap. “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 an American Academy of Neurology press release about the study.
Participants took a battery of tests on their memory and thinking skills, and researchers tested their baby teeth for lead levels indicating prenatal and early postnatal exposure. The study found that prenatal lead exposure, specifically during the second trimester, was associated with lower cognitive test scores, mostly among female participants.
The researchers emphasized that the findings suggest an association between second trimester lead exposure and later in life cognitive function; they do not establish causation.
Hickman highlighted the relevance of the study to public health today. “While lead exposure has declined over recent decades, the Flint water crisis and recent lead contamination in cinnamon applesauce marketed to young children are examples of ongoing exposure problems in the United States, and lead exposure remains an issue globally as well,” she said.
Read the American Academy of Neurology press release: Prenatal lead exposure related to worse cognitive function in adults
