Qualidade do ar e transtornos respiratórios agudos em crianças Air quality and acute respiratory disorders in children

ABSTRACT 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, SO 2 , NO 2 , CO and O 3 were analyzed daily and as closure variables, a total of 45,595 emergency pediatric consultations for respiratory symptoms or speci fi cally 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 O 3 had a positive and statistically signifi cant 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 signifi cant negative association was found with CO and pediatric consultations for respiratory complaints. Other air pollutants were not found to have a signifi cant effect.