BEIJING: Exposure to lead during pregnancy and early childhood may speed up the rate at which children forget information, potentially impairing learning and cognitive development, according to a new study.
The study employed a well-established cognitive test known as the delayed matching-to-sample task to assess memory performance in children aged 6 to 8, Xinhua news agency reported.
Researchers from the Icahn School of Medicine at Mount Sinai, US, applied a novel statistical model — the nonlinear modified power function — which had previously been used in animal and human studies but is now being adapted for environmental health research.
The study found that higher blood lead levels between the ages of 4 and 6 were significantly associated with faster rates of forgetting, even at relatively low levels of exposure, with a median blood lead level of approximately 1.7 micrograms per decilitre.
The findings, published in the journal Science Advances, suggest that even low-level lead exposure can compromise critical cognitive functions during early childhood.
“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, from the Department of Environmental Medicine at the Icahn School.
“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,” he added.
The 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, the researchers said.