Climate and air pollution are associated with pediatric respiratory hospitalizations in São Paulo, Brazil

Abstract

Introduction Environmental and climatic factors have been associated with pediatric respiratory diseases, but these associations may vary across specific clinical outcomes. Methods We conducted a hospital–based study in the Metropolitan Area of São Paulo, Brazil, using pediatric emergency department visits and hospitalizations recorded in 2022. Residential addresses were geocoded and individual environmental exposures were estimated through inverse distance weighting (IDW) interpolation of air pollution and meteorological data. Multivariable logistic regression models were used to evaluate associations between environmental factors, seasonality, and two respiratory outcomes: bronchiolitis and unspecified acute respiratory infections. Results Higher ozone levels, relative humidity, and spring seasonality were significantly associated with greater odds that a respiratory encounter corresponded to hospitalization for bronchiolitis (O3: OR = 1.012; 95% CI 1.005–1.019; relative humidity: OR = 1.016; 95% CI 1.005–1.027). For unspecified acute respiratory infections, lower temperatures were associated with greater odds that a respiratory encounter corresponded to hospitalization for this diagnosis (OR = 0.887; 95% CI 0.793–0.993), while greater odds were also observed during spring. Other environmental variables showed positive but non–significant associations. Discussion Environmental and climatic factors showed differential associations with pediatric respiratory diseases. Disaggregating outcomes may improve the identification of disease–specific patterns of association and support targeted public health strategies in urban settings.