Racial segregation linked to higher lead exposure in Black children

Key takeaways:

• Living in a racially isolated neighborhood is associated with higher childhood lead levels.
• Racial segregation in North Carolina was fairly stable during the study period from 1990 to 2015.

Living in a racially segregated neighborhood is associated with higher levels of lead exposure among Black children, according to study findings published in Pediatrics.

Segregation has also been linked to cancer mortality, obesity and diabetes.

“Our research group has long worked on health and educational disparities,” Marie Lynn Miranda, PhD, who founded the Children’s Environmental Health Initiative at the University of Notre Dame and is now chancellor of the University of Illinois Chicago, told Healio.

“In doing that work, we became increasingly interested in how neighborhood environments shape outcomes for children. This, in turn, led us to examine how racial residential segregation shaped the neighborhood environment,” Miranda said.

Miranda and colleagues studied records from the North Carolina Department of Health and Human Services for 320,916 children aged 6 years or younger who were tested between 1992 and 1996 or 2013 and 2015. They georeferenced blood lead levels to census tracts to compare lead levels with racial residential segregation of non-Hispanic Black families.

“We used a local spatial measure of racial residential segregation, or RRS, that we previously developed to look at how RRS changed over a 25-year time period,” Miranda said. “We then used statistical methods to examine whether levels of RRS were associated with childhood blood lead levels in 1990, which they were, and in 2015, which they were again.”

Ultimately, the researchers found that children living in more segregated areas had higher blood lead levels, with data showing that a 1-standard-deviation increase in tract-level racial isolation was associated with a 2.86% increase in blood lead level among non-Hispanic Black children from 1992 to 1996.

In the period from 2013 to 2015, the association was decreased but persisted, with a 1-standard-deviation increase in tract-level racial isolation associated with a 1.59% increase in blood lead content among non-Hispanic Black children.

The researchers also found that racial segregation was fairly stable from 1990 to 2015, with 38.7% of communities not changing in terms of racial isolation.

“I’m sorry to say that we were not surprised by the results,” Miranda said. “We often see children of color exposed to higher levels of social and environmental stressors.”

Miranda and colleagues have planned future studies of the racial isolation index to find what other effects it has on children and families.

“We plan to examine whether other environmental exposures are also associated with RRS,” Miranda said. “The racial isolation index that we calculated is also available to other researchers to use.”

She added that it was still important for providers to screen at-risk children for lead exposure.

“We need to advocate for safer and healthier housing and neighborhoods for our children,” Miranda said.