Air pollution and pediatric respiratory hospital admissions in São Paulo, Brazil

In order to investigate the relation between air pollution and child morbidity in São Paulo, a time-series study was carried out. Daily records of hospital admissions for children under 13 years old were obtained at the Health State Secretary, covering 112 hospitals in the period from October 1992 to October 1993. Daily levels of PM10, ozone, SO2, CO and NO2 were obtained from the environmental state agency (CETESB), while both CETESB and the Institute of Astronomy and Geophysics (IAG) of the University of São Paulo provided daily measures of temperature and relative humidity. Daily counts of child respiratory admissions (RESP) were considered as the dependent variable of pollutants in regression models, controlled for months of the year, days of the week, weather factors, and the daily number of non respiratory admissions (NORESP). PM10 and ozone were the pollutants that exhibited the most robust association with RESP. The mean levels of PM10observed during the period of study (70 μg m−3) were associated with an increase of 12% in RESP. The association between air pollution and RESP was significant within a time lag between 1 to 7 days and was dose-dependent. This result indicates that air pollution represents a significant pediatric health problem in São Paulo.