Evaluation of Seasonal and Spatial Variations of Air Quality Index and Ambient Air Pollutants in Isfahan Using Geographic Information System

Introduction: Due to more than 1.7 million population, many vehicles and large industries around Isfahan, it has become one of the most polluted cities in Iran. The aim of this study was a spatial analysis of the concentrations of air pollutants and the air quality index (AQI). Materials and Methods: In this descriptive and evaluative study, the air quality data of 7 monitoring stations in 2012 were taken from the Isfahan Department of Environment. The calculation of AQI was done as per the EPA guidelines. The zoning pollutant concentrations and AQI in the study area was determined with the use of the Arc map software, version 10.1. Results: The results showed that the highest concentrations of pollutants and the AQI were related to the Ahmadabad station. Moreover, the air quality in Isfahan in 2012 was 4.38% (4 days) in good conditions, 12.7% (47 days) in moderate conditions, 42.56% (156 days) in unhealthy conditions for sensitive groups, 39.49% (144 day) in unhealthy conditions, 2.8% (10 days) in a very unhealthy and 1.2% (4 days) in dangerous conditions, respectively. Conclusion: It was found that particulate matter was the main cause of Isfahan air pollution while Ahmadabad is the most polluted point in Isfahan. According to the calculations, during 314 days of the year 2012, the air quality of Isfahan was in unhealthy conditions and only 4 days was in good conditions. This is one of the biggest health challenges in this city.