Lead exposure in racially segregated housing lowers reading scores among Black children: study

·3 min read

Story at a glance

  • Any exposure to lead can cause lower cognitive performances among children.

  • Although the U.S. federal government outlawed use of lead-based paint in 1978, many homes in racially segregated neighborhoods still contain traces of the contaminant.

  • Using data from North Carolina, researchers found Black children, who are more likely to live in these neighborhoods, had lower reading test scores than their white counterparts due to high brain lead levels.

The negative effects of lead exposure on human health have long been documented, but new research published in Proceedings of the National Academy of Science show racially segregated neighborhoods play a large role in who is exposed to lead in early childhood and the detrimental cognitive outcomes associated with exposure.

Data collected from North Carolina show lead exposure results in lower fourth-grade standardized test scores in all children, but non-Hispanic Black children are more likely to live in racially segregated neighborhoods and be exposed to lead, underscoring the long-term impacts of structural racism.

Where lead exposure is the highest is just one piece of the puzzle, explained study co-author Mercedes Bravo of the Global Health Institute at Duke University and a faculty affiliate of Notre Dame’s Childhood Environmental Health Initiative (CEHI), in a statement.

“Black children are more likely to be exposed to lead and are also more likely to live in racially segregated, predominantly Black neighborhoods. When these two exposures co-occur, children had worse-than-expected scores,” Bravo said. “Identifying these combinations of environmental, social and economic exposures, and interactions between them, can inform the targeting and design of interventions in vulnerable communities.”

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Any home built in the United States before 1978 has an increased chance of containing lead-based paint, lead-contaminated dust and pipes and plumbing fixtures with lead, while racially segregated neighborhoods are more likely to have homes built before this cutoff.


According to the United States Environmental Protection Agency (EPA) the federal government banned consumer use of lead-based paint in 1978, although several states banned the product earlier.

There is no safe level of lead exposure, researchers stressed, and any childhood lead poisoning is preventable.

To conduct the analysis, investigators assessed geocoded birth data from over 25,000 North Carolinians, blood lead surveillance data, and fourth-grade standardized test scores.

Higher blood lead levels were linked with lower mathematics test scores among all children. Non-Hispanic Black children with higher blood lead levels and residing in racially isolated neighborhoods exhibited worse reading scores.

Researchers defined racial residential segregation as “the geographic separation of Black individuals and communities from other racial/ethnic groups into separate, unequal neighborhoods,” which “fosters environments inimical to health through disinvestment of resources and concentration of disadvantages.”

Academic achievement in early childhood can predict educational outcomes later in life, authors explained, noting non-Hispanic Black and Hispanic individuals tend to have lower high school and college graduation rates. The data presented indicate this so-called “achievement gap” can be attributed in part to the lasting effects of structural racism.

“In the midst of our country’s racial reckoning, we must work harder to understand and ultimately act on the deep effects that environmental justice and structural racism have on our country and our communities,” added co-author Marie Lynn Miranda, director of the CEHI and professor of applied and computational mathematics and statistics at the University of Notre Dame.

“This paper tackles both issues head on by showing that a clear issue of environmental justice (childhood lead exposure) is further compounded by the structural racism that Black families in particular face in the United States, as demonstrated through racial residential segregation.”

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