Determination of Dispersion and Zoning of Air Pollutants in Tehran Using AERMOD Model: A Case Study of District 2 of Tehran, Iran

Background: Cities, as population centers, face increasingly diverse environmental problems. Hence, there is an urgent need for a healthy environment by eliminating the emission of various life-threatening air pollutants with different origins. The present study aimed to determine the air pollution zones using the AERMOD model and provide a strategic management plan to reduce air pollution in District 2 of Tehran, Iran. Methods: In this study, the air pollutant dispersion was evaluated by the AERMOD model exploiting spatial analysis (interpolation) and field measurements. The samples were collected from 32 places in the North, South, Central, East and West of District 2 of Tehran. Air quality indices, including ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide were analyzed in the experiments. Zoning and mapping of dispersion maps and spatial analysis were performed by ArcGIS.10 software using inverse distance weighted interpolation methods in the study area. Results: According to the results, the highest concentrations of sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide pollutants were related to stations 28, 26, 15 and 15 with values of 10.9, 54.6, 32.8, and 31.9 ppb, corresponding to the southern, eastern, southern, and southwestern regions in Sharif, Punak, and Kuy-e Nasr neighborhoods, respectively. Conclusion: Based on the statistical tests of correlation coefficient, normalized mean error, and normalized mean bias, all the calculated results confirmed the accuracy of constructed model and that the modeling would not have sufficient accuracy and performance without the implementation of AERMAP.