Role of passenger cars and taxies in air pollution of Tehran, Iran

Air Pollution is one of the significant problems in Tehran. Understanding the role of different sources can result in better decision-making. Some pollutions are not emitted directly from sources and are present in the atmosphere due to chemical reactions. Therefore, using air quality modeling can be beneficial to our understanding of these phenomena. An air quality modeling system was used first to model the base case of ambient pollutions. Then, the emissions of passenger cars and taxies were omitted separately to determine the role of their contribution to air pollution. The modeling results showed an acceptable performance with the index of agreement of 0.84 and 0.61 for ozone and particle matter (PM), respectively. The accumulated contribution of passenger cars and taxies to PM AQI was 14 units. However, their role in ozone formation was complex.