Asghar Yaghouti Soltan Ahmadi - Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Seyed Alireza Hajiseyed Mirzahosseini - Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Yousef Rashidi - Environmental Sciences Research Institute, Shahid Beheshti University, Tehran, Iran.
Nabiyollah Mansouri - Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.

Background: According to the heavy traffic in Tehran, a high amount of ۱, ۳-Butadiene (BD) in this city is highly expected. This study estimated the lifetime cancer risk (LCR) attributable to BD in District ۹ of Tehran Municipality and simulation of its releasing way.Methods: This research is an applied study that was conducted in the form of field research. Cancer risk assessment was carried out based on the United States Environmental Protection Agency (USEPA) method. BD concentration measurements were performed at ۳۰ points and specified in the area and daily at three different times in four seasons since autumn of ۲۰۱۹ till summer of ۲۰۲۰. LCR then was calculated for four different groups of residents, employees, first and second classes of the pedestrian. Finally, the way of releasing BD in the District ۹ was evaluated by GIS software.Results: The results showed that the highest and lowest BD concentrations were ۲۸۱۹ and ۴۲۴ ppb, respectively, in autumn and spring. They were measured in the north and west side of the District ۹ which were much higher than inhalation reference concentration. In addition, the LCR estimation of population due to exposure to high level of BD was exceeded the USEPA benchmark of ۱×۱۰-۶ in the ۴ specified groups. So, the amount of LCR in the residents was ۷۹۰ times more than the USEPA benchmark.Conclusion: According to the results, the necessity for traffic control by urban management and producing green vehicles to prevent pollutants emission is essential.

۱, ۳-Butadiene, Carcinogenic risk, Lifetime Cancer Risk (LCR), Air pollution, GIS