Air pollution and hospitalizations in the largest Brazilian metropolis

ABSTRACT OBJECTIVE To evaluate the impact of air pollution on hospitalizations for respiratory and cardiovascular diseases in the largest Brazilian metropolis. METHODS This study was carried out at the Metropolitan Region of São Paulo, Brazil. Environmental data were obtained from the network of monitoring stations of nine municipalities. Air pollution exposure was measured by daily means of PM10 (particles with a nominal mean aerodynamic diameter ≤ 10 μm) per municipality, while daily counts of hospitalizations for respiratory and cardiovascular diseases within the Brazilian Unified Health System were the outcome. For each municipality a time series analysis was carried out in which a semiparametric Poisson regression model was the framework to explain the daily fluctuations on counts of hospitalizations over time. The results were combined in a meta-analysis to estimate the overall risk of PM10 in hospitalizations for respiratory and cardiovascular diseases at the Metropolitan Region of São Paulo. RESULTS Regarding hospitalizations for respiratory diseases, the effect estimates were statistically significant (p