Objective: To assess the relationship between air pollution and acute respiratory disorders in children.
Methods: A time series ecological study was carried out in three public health posts in a region of the city of Rio de Janeiro (Southeastern Brazil), between April 2002 and March 2003. Data for PM10, SO2, NO2, CO and O3 were analyzed daily and as closure variables, a total of 45,595 emergency pediatric consultations for respiratory symptoms or specifically for disorders in the upper and lower airways. To control for confounders, other variables were included in the model including those relating to weather, seasonality, temperature, relative air humidity, rain volume, respiratory infections and the calendar effects (such as holidays and weekends). A Poisson regression was applied using generalized counting models to estimate the effects of pollutants and confusing factors.
Results: Only O3 had a positive and statistically significant effect, both among emergency consultations for respiratory problems and consultations for symptoms relating to the lower airways. Effect and exposure occurred on the same day (lag 0). A significant negative association was found with CO and pediatric consultations for respiratory complaints. Other air pollutants were not found to have a significant effect.
Conclusions: There were found associations between outdoor air pollution and the number of emergency pediatric consultations for respiratory problems in the studied area, in spite of the fact that the levels of all pollutants monitored during the study period were below recommended levels.