Association between prenatal ambient particulate matter and childhood asthma is modified by community safety and child sex

Studies document independent effects of prenatal air pollution exposure and social environmental factors, including neighborhood safety, on childhood asthma development with documented sex-specific effects. Further research examining these factors jointly is needed. We examined associations between prenatal residence-level daily fine particulate matter (PM_2.5) exposure and child asthma, considering effect modification by a validated Neighborhood Sentiment and Safety Index (NSSI) and child sex. Participants were mothers and full-term (> 37 weeks gestation) singleton-born children from two Boston-area pregnancy cohorts. The Asthma Coalition on Community, Environment and Social Stress (ACCESS) project enrolled 955 pregnant women between August 2002 and July 2009.The Programming of Intergenerational Stress Mechanisms (PRISM) study recruited 390 pregnant women from March 2011 to December 2013. Bayesian distributed lag interaction models (BDLIMs) were implemented to estimate associations between child asthma incidence and daily average maternal PM_2.5 exposure across gestation. Effect modification by NSSI and child sex was examined using a BDLIM comparing models with and without effect modification. Women were primarily minorities (29% black, 47% Hispanic) reporting less than a high school education (54%). Children were followed 15.1 ± 3 years; 204 (17%) developed asthma. In the overall sample (n = 1,178), increased PM_2.5 exposure between 21 and 27 weeks gestation was associated with increased odds of asthma in children born to women in the high NSSI group (NSSI ≥ 75th percentile representing safer neighborhoods). Both boys and girls were at higher risk of asthma when considering joint effects. These data add to a growing literature highlighting the need to consider both chemical toxins and psychosocial factors operating in communities to better elucidate which factors are driving respiratory health effects. A singular focus on changes to mitigate air pollution may not have high impact on improving respiratory health, particularly in historically under-resourced areas where effects may be more highly driven by social determinants.