This brief was developed using Microsoft Copilot and edited by Charlotte Sutcliffe, Duke undergraduate research assistant; for full text and references see
Bravo, M. A., & Miranda, M. L. (2021). Effects of accumulated environmental, social and host exposures on early childhood educational outcomes. Retrieved from https://doi.org/10.1016/j.envres.2021.111241
Background:
Persistent racial disparities in early childhood academic performance are influenced by a complex interplay of environmental, social, and biological (host) exposures. This study investigates how these exposures - specifically birthweight percentile, childhood lead exposure, maternal smoking during pregnancy, economic disadvantage, and neighborhood racial isolation - affect standardized test scores in reading and mathematics among non-Hispanic Black (NHB) and non-Hispanic White (NHW) children in North Carolina. Using data from birth records, blood lead surveillance, and 4th grade test scores, the study evaluates both the prevalence of these exposures and their individual and combined effects on educational outcomes.
Findings:
NHB children were disproportionately exposed to multiple adverse conditions: they were more likely to be economically disadvantaged (80% vs. 40% for NHW), live in highly racially isolated neighborhoods (46% vs. 5%), have higher blood lead levels (mean 4.6 vs. 3.7 μg/dL), and be born at lower birthweight percentiles. Conversely, NHW children were more likely to have mothers who smoked during pregnancy. Across both groups, higher birthweight percentiles were associated with better test scores, while economic disadvantage, maternal smoking, and elevated lead levels were linked to lower scores.
Neighborhood racial isolation significantly affected NHB children’s outcomes: those in the most racially isolated areas scored 1.54 points lower in reading and 1.12 points lower in math compared to peers in the least isolated areas. These effects were not observed for NHW children. Although no statistically significant interactions were found between exposures (e.g., lead and birthweight), NHB children more frequently experienced multiple adverse exposures simultaneously, compounding their educational disadvantages.
Takeaways:
This study demonstrates that NHB children face a higher cumulative burden of adverse environmental, social, and biological exposures, which collectively contribute to lower academic performance. While individual exposure effects may appear modest, their combined impact is substantial and disproportionately affects NHB children. Notably, neighborhood racial isolation emerges as a critical, modifiable determinant of educational disparities. These findings highlight the need for policies that address structural inequities - such as residential segregation and environmental health risks - to promote educational equity and long-term well-being for all children.