Associations between ambient fine particulate matter and child respiratory infection: The role of particulate matter source composition in Dhaka, Bangladesh. (1st December 2021) - Sherris, Allison R.
Abstract: Air pollution in the form of fine particulate matter (PM2.5 ) has been linked to adverse respiratory outcomes in children. However, the magnitude of this association in South Asia and sources of PM2.5 that drive adverse health effects are largely unknown. This study evaluates associations between short-term variation in ambient PM2.5 and incidence of pneumonia and upper respiratory infections among children in Dhaka, Bangladesh. We also perform an exploratory analysis of the PM2.5 source composition that is most strongly associated with health endpoints. We leveraged data from health surveillance of children less than five years of age between 2005 and 2014 in Kamalapur, Bangladesh, including daily physician-confirmed diagnoses of pneumonia and upper respiratory infection. Twice-weekly source-apportioned ambient PM2.5 measurements were obtained for the same period, and Poisson regression adjusted for time-varying covariates was used to estimate lagged associations between ambient PM2.5 and respiratory infection. We use complementary matching and stratification approaches to evaluate whether these associations vary across PM2.5 source composition. Total PM2.5 mass was associated with a modest increase in incidence of pneumonia, with a peak effect size two days after exposure (rate ratio = 1.032; 95% confidence interval = 1.008–1.056). We did not identify a significant association between PM2.5 and upper respiratory infection. Stratified and matching analyses suggested this association was stronger among days when ambient PM2.5 had a higher mass percent associated with brick kiln and fugitive lead emissions.: This study suggests that elevated ambient PM2.5 contributes to increased incidence of child pneumonia in urban Dhaka, and that this relationship varies among days with different source composition of PM2.5 . Graphical abstract: Image 1 Highlights: Daily ambient PM2.5 associated with increased incidence of child pneumonia in Dhaka. No association found between daily PM2.5 and child upper respiratory infection. Novel approachesutilized to explore role of PM2.5 source composition in association with health effects. Particulate matter source composition modified the link between PM2.5 and pneumonia. Health effects of brick kiln and fugitive lead particles merit continued study. Abstract : This study suggests that elevated ambient PM2.5 contributes to increased incidence of child pneumonia in urban Dhaka, and that this relationship variesby the source composition of PM2.5 .