Reproductive
Long-term exposure to ambient air pollution concentrations and fecundability among U.S. Black women Sydney Carolan* Sydney Carolan Carolan Carolan Carolan Carolan Carolan Carolan Carolan Carolan Carolan Carolan Boston University School of Public Health
Previous research shows associations between air pollution and infertility. However, few studies have included large numbers of Black women, despite documented inequitable exposures to air pollution in the United States. Using data from the Black Women’s Health Study, a prospective cohort study of 59,000 U.S. Black women, we examined the association of long-term exposure to ambient air pollution with fecundability, the per-cycle probability of conception. Participants enrolled in 1995 and are followed by biennial questionnaires. In 2011, participants were asked about time-to pregnancy for planned pregnancies that resulted in a birth and unsuccessful pregnancy attempts. Our analysis included 2,199 pregnancy attempts from 1,716 participants during 1995-2011. We used annual average ambient concentrations of particulate matter ≤2.5 µm (PM2.5), nitrogen dioxide (NO2), and ozone (O3) estimated using spatiotemporal models and linked to geocoded participant addresses. We fit proportional probabilities regression models with generalized estimating equations to estimate fecundability ratios (FR) and 95% confidence intervals for each pollutant adjusting for age, calendar year, geographic region, educational attainment, neighborhood SES, and co-pollutants. We fit adjusted generalized additive models (GAM) with smooth terms to assess joint effects and non-linear associations between pairs of pollutants. Residential concentrations of NO2 and O3 were associated with decreased fecundability: FRs for a 5-ppb increase in exposure were 0.93 [95% CI: 0.88-1.00] and 0.92 [95% CI 0.85-1.00], respectively. In contrast, PM2.5 exposure was associated with greater fecundability (FR=1.26 per 5-µg/m3 increase, 95% CI: 1.09-1.46). GAM results indicated little evidence of non-linear associations or interactions between pollutants. Our findings add to the body of evidence for federal air quality standards aimed at mitigating the impact of air pollution on adverse reproductive health outcomes.