effect of air pollution in frequency of hospitalizations in asthmatic children

asthma is one of the most common diseases in childhood, which has been increased during last decade because of epidemiological pattern changes with climate and industrialization of the communities. there are some controversies on the relationship between air pollution and asthma. tehran, as the capital of iran, is one of the densest populations and is one of the most polluted cities in the world. this study was performed to search effects of various air pollutants using gis-based modeling on the rate of hospitalizations due to asthma in children in tehran. information of patients who were admitted with a diagnosis of asthma in a referral pediatric hospital was checked and the total number of admissions in the same age range (2 to 14 years) during a 2-year period (march 2009-march 2011) were calculated. information about air pollutants including carbon monoxide, nitrogen dioxide, ozone, and sulfur dioxide, obtained from the air quality control center. days of the year divided into good and nongood days according to the guideline for reporting of the daily air quality index (aqi). two thousand two hundred nineteen cases enrolled in the study and asthma admission to total admission ratio compared with air pollutants data in admission day (725 days), using nonlinear regression method. analysis of the data revealed that there is a significant relationship between nongood nitrogen dioxide ( p =0.01), ozone ( p =0.01), and sulfur dioxide ( p =0.04), levels and admission due to asthma in children, but there was no significant relationship between carbon monoxide levels and asthma admission in children. a significant relationship between nitrogen dioxide, ozone and sulfur dioxide concentration in air and admission due to asthma at levels other than good, reveals air pollutants levels can be significantly harmful to children before aqi reaches to hazardous levels.