Having heavy impacts on human’s life, pollution adversely influences life. In this paper, a comprehensive model of the Arak’s air pollution for different pollutant chemicals NOx, CO, and SO2 is developed. Here, all effective fixed and mobile sources of pollution are within 50 km distance of the city. The topology of ground surface and also climate patterns of different local areas were carefully considered to accurately model the distribution of pollution. Then, comparing the results with data taken from the ambient air monitoring, the model was validated. According to our findings maximum of NOx concentration in Arak city, Iran was 7.7 times of standard value. This figure is 2.2 and 17.5 times for CO and SO2 pollutants. Share of industry, for spring season, is 51%, 86% and 100% for NOx, CO, and SO2, respectively. Moreover, IRALCO itself has 31% share in total NOx pollution, while its share for CO and SO2 pollution dramatically increases to 85% and 100%, respectively.