Assessing theEffects of Nitrogen Dioxide in Urban Air on Health of West and Southwest Cities of Iran

Background: Nitrogen dioxide (NO2) is a corrosive, strong oxidant and a physiologic stimulant of lower respiratory tract. Every human being inhales an average of 10-m3 air per day; therefore, assessment of the effect of inhaled air on health is a vital issue. The main source NO2 in urban regions is intra-urban public transport system. The annual average of determined air quality for NO2 is 40 ?g/m3. Objectives: The present study aimed to estimate and compare epidemiologic indices attributed to the pollutant NO2 in the urban air of southwest cities of Iran, namely, Ahvaz, Kermanshah, and Bushehr, in 2011. Materials and Methods: In the present study, data relevant to the air-pollutant NO2 in 2011 was obtained from the Iranian Department of Environment and meteorological organizations of the studied cities. Raw data processing by Excel software included instruction set correction of averaging, coding, and filtering. Then the meteorological parameters were converted as input file to the Air Q model. Finally, by using epidemiologic formulas, relative risk (RR) and attributed part to NO2 in the three studied cites were estimated. Results: The results showed that in summer, winter, and the whole year, Kermanshah and Bushehr had on average the maximum and minimum NO2 concentration, respectively, in 2011. In addition, accumulative number of cases attributed to exposure with NO2 in the studied cities was maximum in Kermanshah (21 cases) and minimum in Bushehr (one case). The results revealed that approximately, the maximum number of death cases attributed to NO2 were observed in Kermanshah due to heart problems (1.06%), acute infarction (1.8%), and obstructive pulmonary disease (1.9%) with concentration > 20 ?g/m3. Conclusions: Every 10 ?g/m3 increase in the concentration of the pollutant NO2 in the studied cities led to increase in the RR of myocardial infarction, cardiovascular diseases, and obstructive pulmonary disease by 0.4%, 0.2%, and 0.4%, respectively, in 2011. Higher RR value can depict mismanagement in urban air quality. The lower level of RR value might be achieved if some control strategies for reducing NO2 emission were used.