Lead exposure in early life linked to faster memory loss in children

A study led by researchers at the Icahn School of Medicine at Mount Sinai shows that exposure to lead during pregnancy and early childhood may accelerate the rate at which children forget information-a critical marker of memory impairment that may have implications for learning and development.

Using delayed matching-to-sample task (DMTS)-a cognitive task that can be used to evaluate underlying neurobehavioral functions, such as attention and working memory, and has been demonstrated to be sensitive to metal neurotoxicants-the study examined how both prenatal and early childhood blood lead levels affect working memory in children ages 6 to 8. In this task, the children were presented a picture, and then had to select that same picture from three choices presented after a brief delay. The study was published in Science Advances on July 9, 2025.

Researchers applied an innovative statistical approach known as a nonlinear modified power function to model memory decay, uncovering a measurable link between higher childhood lead levels and faster forgetting rates.

The findings showed that higher lead exposure at ages 4–6 was significantly associated with a faster rate of forgetting-even at low median blood lead levels (~1.7 µg/dL). Additionally, older children and those whose mother's IQ was higher were more likely to show better memory retention.

The nonlinear modified power function has been validated in previous animal and human studies but is now applied in the field of environmental health. This new usage is important because children are exposed to many environmental chemicals, and this model provides a validated method to further assess the effect of additional environmental exposures, such as heavy metals, air pollution, or endocrine disruptors, on children's working memory."

Katherine Svensson, PhD, MS, postdoctoral fellow in Environmental Medicine at the Icahn School of Medicine at Mount Sinai and co-first author of the study

This study also validates a method for assessing neurobehavioral function, paving the way for translational research that can bridge human data with mechanistic insights from laboratory studies.

"Our work advances the current literature by incorporating operant tests-specifically the DMTS-which are commonly used in animal toxicology studies but sparse in human studies. This translational approach is a key innovation of our work," said Jamil M. Lane, PhD, MPH, Instructor, Environmental Medicine, Icahn School of Medicine at Mount Sinai, and co-first author.

The implications are clear: even low-level lead exposure can undermine key cognitive functions in young children. As memory and attention are foundational for academic and social success, this research underscores the urgent need for continued investment in lead prevention efforts-especially in historically overburdened communities.

"There may be no more important a trait than the ability to form memories. Memories define who we are and how we learn," said Robert Wright, MD, MPH, Ethel H. Wise Chair of the Department of Environmental Medicine and Co-Director of the Institute for Exposomic Research at the Icahn School of Medicine at Mount Sinai. "This paper breaks new ground by showing how environmental chemicals can interfere with the rate of memory formation. Children with higher levels of blood lead forgot the test stimulus faster than those with low blood lead levels."

This study opens the door for future work to explore how environmental exposures like lead intersect with other cognitive domains such as attention, executive function, and reward processing. It also strengthens the case for policy interventions that protect children's developing brains before irreversible harm occurs.