Exposure to ambient air pollution and prevalence of asthma in adults

Air pollution is defined as the risk factors for asthma. This study aimed to investigate the effect of exposure to ambient air pollution and prevalence of asthma in adults. This cross-sectional study was done between November 2015 and February 2016. The asthma prevalence was surveyed in 3172 adults between 20 and 44 years old in Tehran, Iran. Face to face interview and standardized questionnaire (European Community Respiratory Health Survey (ECRHS)) were used for data gathering. Concentrations of air pollutants in the whole city of Tehran were obtained from Tehran Air Quality Control Company (AQCC). Air pollution exposure assessed by the spatial analysis based on GIS method. The effect of ambient air pollution on the asthma symptoms was assessed with the crude and adjusted logistic regression. Results were reported as odds ratios (OR) with 95% confidence interval (CI). Results showed that the asthma prevalence in adults in Tehran was 11.73%, higher than the average prevalence of asthma in the whole country equal to the 8.9%. The prevalence of asthma in males (6.43%, n=204) was significantly higher than females (5.26%, n=167), but this difference was not significant (P = 0.29). A significant positive association was observed between the asthma prevalence and the concentration of CO (OR 1.64; 1.26 to 1.85) and PM10 (1.04; 1.01 to 1.08) (P <0.05). Finally, we concluded that exposure to some air pollutants can affect the asthma prevalence in adults. Therefore, control of air pollution is recommended to reduce the asthma in Tehran metropolis.