The risk of lead exposure in personal living spaces is still alive and well in the U.S.–and this is particularly true for lower income families. This is a serious problem because a new scientific study has demonstrated that living in neighborhoods with high risks of lead exposure is associated with differences in brain structure and cognitive performance in some children and adolescents.
No amount of lead is safe. Even at very low levels, cognitive deficits have been attributed to lead exposure. More than 72,000 neighborhoods in the United States have been assigned risk estimates for lead exposure, based on the age of homes and poverty rates. Though new houses haven’t used lead-based paint since 1978, many older homes still contain lead hazards.
Researchers examined the association of lead exposure risk with cognitive testing and brain scans to examine cognitive abilities and brain structure in more than 9,500 children living in the U.S.
Study results overview
The associations between lead risk and decreases in cognitive performance and brain structure are more pronounced in lower income families. The results showed that an increased risk of lead exposure was associated with decreases in cognitive performance and in the surface area and volume of the cortex — the surface of the brain, responsible for initiating conscious thought and action. But this was not true for children from mid- or high-income families…Decreased cognitive scores and structural brain differences were only observed in lower-income families.
Journal Reference: Andrew T. Marshall, Samantha Betts, Eric C. Kan, Rob Mcconnell, Bruce P. Lanphear & Elizabeth R. Sowell. Association of lead-exposure risk and family income with childhood brain outcomes. Nature Medicine, 2020 DOI: 10.1038/s41591-019-0713-y