Redlining in New York City: impacts on particulate matter exposure during pregnancy and birth outcomes

Evidence suggests historical redlining shaped the built environment and health outcomes in urban areas. Only a handful of studies have examined redlining's association with air pollution and adverse birth outcomes in New York City (NYC). Additionally, no NYC-specific studies have examined the impact of redlining on birth weight.

This longitudinal cohort study analysed data from the National Institute of Health Environmental Influences on Child Health Outcomes Programme to investigate the extent to which maternal residence in a historically redlined neighbourhood is associated with fine particulate matter (PM_2.5) exposure during pregnancy using multivariable regression models. Additionally, we examined how maternal residence in a historically redlined neighbourhood during pregnancy influenced birth weight z-score, preterm birth and low birth weight.

Our air pollution model showed that living in a historically redlined census tract or an ungraded census tract was associated with increased PM_2.5 exposure during pregnancy. We also found living in a historically redlined census tract or an ungraded census tract was associated with a lower birth weight z-score. This finding remained significant when controlling for individual and census tract-level race, ethnicity and income. When we controlled PM_2.5 in our models assessing the relationship between redlining grade and birth outcome, our results did not change.

Our study supports the literature linking redlining to contemporary outcomes. However, our research in ungraded tracts suggests redlining alone is insufficient to fully explain inequality in birth outcomes and PM_2.5 levels today.