Beyond Black and White: Relationships between Segregation, Environmental Burden, and Birth Outcomes among Black and Latino populations

Segregation measures over time likely mask the movement of Latinos into predominantly non-Hispanic Black (NHB) areas. Due to systematic disinvestment, the co-location of NHB and Latinos may correlate with environmental and social stressors. We construct a combined racial isolation (RI) measure for Blacks and Latinos for the 72 246 contiguous U.S. census tracts. We compare trends (1990-2015) in RI of NHB individuals and RI of NHB and Hispanic individuals (RI-NHB + H). We estimate correlations between RI-NHB + H and CDC Environmental Justice Index (EJI) components. We assess associations between EJI, RI-NHB + H, and birthweight percentiles using North Carolina detailed birth records (n = 504 363; 2015-2019). Between 1990-2015, RI-NHB + H and RI-NHB increased in most (88.7%) and the majority (69.1%) of U.S. census tracts, respectively. The largest local, spatial correlations between RI-NHB + H and EJI occurred in the southeast, southwest, and parts of the west coast, where both are high. For NHB and NHW mothers, the association between EJI and birthweight percentiles was increasingly negative at higher levels of RI-NHB + H. Among Hispanic mothers, the association was negative at mid RI levels, but not at high RI levels. Our results underscore the changing nature of segregation in the U.S. and illuminate cumulative impacts experienced by NHB and Latino populations on reproductive health.