Evaluation of peak expiratory flow in adolescents and its association with inhalable particulate in a Brazilian medium-sized city.

INTRODUCTION: High particulate matter (PM10) concentrations are associated with increased incidence of respiratory symptoms and decreased lung function. This study evaluates the air pollution effects in children's and adolescents' lung function using peak expiratory flow (PEF) measurements over a given period, in an area exposed to industrial emissions. METHODOLOGY: This was a panel study. The effects of air pollution on respiratory symptoms and PEF were investigated in 117 children and adolescents from three public schools in areas of exposure to air pollution from a mining company in a Brazilian medium-sized city, from 2008 to 2009. The average daily PM10, temperature and humidity were recorded by the monitoring network in the region. Association between daily records of PEF and PM10 was assessed in mixed-effect regression models, controlling for temperature, humidity, and body mass index. RESULTS: About 60,000 PEF measurements were performed. Increases of 14µg/m3 in PM10 were associated with decreased PEF in the morning (-1.04%, 95%CI -1.32; -0.77) and evening (-1.2%, 95%CI -1.49, -0.92). DISCUSSION: We found a significant negative association between particulate matter and peak expiratory flow rate in this population, and these remained significant even after adjusted for temperature, humidity, body mass index, coughing, wheezing and coryza. CONCLUSION: Adverse effects were found and it suggests an association between increase in PM10 and reduced lung function.