Environment/Climate Change
Neighborhood Socioeconomic Conditions and Disparities in Birth Weight: Investigating Mediation by Prenatal Exposure to Multiple Air Pollutants Nan Ji* Nan Ji Erika Garcia Rima Habre Shohreh F. Farzan Theresa M. Bastain Carrie V. Breton
Background: Despite the strong evidence that prenatal air pollutant exposure is impacted by neighborhood socioeconomic (NSES) and associated with downstream birthweight (BW), the mediating role of prenatal exposure to multiple air pollutants in the NSES and BW relation has not been examined. Our study examined the mediation effect of multiple air pollutants during pregnancy in the association between NSES and BW. Methods: BW were abstracted from medical records for women participating in the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) study—a pregnancy cohort of predominantly low-income Hispanic/Latina women in Los Angeles. One-year averaged Child Opportunity Index overall and from the social and economic domain (COI and COI-SE) before pregnancy were obtained based on participant’s residential address. Primary mediators were pregnancy-averaged concentrations of 10 air pollutants. Mediation effects of these pollutants were examined using a regression-based approach (cmest R package) and adjusting for potential confounders (N = 702). Results: Compared to those exposed to the lowest quartile, women exposed to the 4th quartile of COI and COI-SE had heavier babies at birth, with increased BW of 41.9 grams (g ; 95%CI: -5.8 g, 89.6 g) and 34.4 g (-11.4 g, 80.2 g), respectively. Nitrogen dioxides (NO2) exposure during pregnancy was found to mediate 10.0 g (0.1 g, 19.9 g) and 8.5 g (0.1 g, 16.9 g) of the observed NSES-BW association. Conclusions: Women living in high-opportunity neighborhoods (high COI and COI-SE) before pregnancy delivered infants with higher BW. These positive associations were partially mediated by NO2 exposure during pregnancy. Our next steps include (1) using structural equations modeling to assess the mediation effect of trimester-specific air pollutants; (2) using dimension-reduction approaches to assess the mediation effect of air pollutant mixtures.
