Associations between air pollution and pediatric asthma hospitalizations across vulnerable groups in Louisiana

Different socioeconomic and racial groups experience different environmental and health burdens across the United States, including for asthma. Understanding the disparate health effects of air pollution on asthma in Louisiana, a particularly vulnerable region, is limited.

To evaluate whether associations of air pollution with pediatric asthma exacerbation vary across vulnerable groups in Louisiana.

We analyzed 28,499 asthma hospitalization cases for <18-year-old individuals across Louisiana from 2010 to 2019 using a time-stratified case-crossover design, with a distributed lag nonlinear model up to 3-lag days. Conditional logistic regression was used to estimate odds ratios (OR) for associations between PM_2.5, O₃, and NO₂ exposures and asthma hospitalizations. NO₂ data were limited to 2010-2016. Race and socioeconomic (by Medicaid status) effect modification were examined.

Cumulative exposures across lags 0-3 days were significantly associated with increased odds of asthma hospitalization for PM_2.5 (OR = 1.079; 95% confidence interval = [1.052, 1.107]), O₃ (1.082 [1.050, 1.116]), and NO₂ (1.071 [1.034, 1.111]). Race-effect modification was not significant. Despite this, significant lag-specific patterns differed by race, with associations observed at lags 1-2 among Black children and at lag 3 among White children. In multipollutant models, associations were attenuated for O₃ and NO₂, while PM_2.5 remained positively associated with asthma hospitalizations.

Short-term increases in air pollution exposures are associated with an increased risk of hospitalizations for asthma among young populations in Louisiana. Given cumulative associations were similar across subgroups, the higher burden among Black children potentially highlights persistent exposure disparities. Reducing air pollution exposure may improve pediatric respiratory health.