Pre- and postnatal environmental lithium exposure and adolescent neurodevelopment: a tooth-biomarker study

Lithium is a naturally occurring element found in drinking water, and its environmental presence is rising with demand for batteries. Yet evidence on lithium comes almost entirely from adults, ecological studies, or medical treatment, leaving the effects of prenatal and early postnatal environmental exposure unknown. We laser-mapped lithium in shed baby teeth, which preserve a record of exposure around birth (-12 to +13 weeks), from 448 U.S. youth in the Adolescent Brain Cognitive Development Study and tested associations with brain structure, cognition, and behavior at ages 9-10. Higher lithium was found in children of less-educated caregivers and from more deprived neighborhoods. Higher lithium was also linked to thicker cortices, varying surface area, mostly smaller subcortical volumes, poorer reading and language ability, and more externalizing problems, with associations varying by caregiver education. Early-life environmental lithium exposure may therefore be socioeconomically patterned and contribute to disparities in neurodevelopment, warranting environmental health surveillance.