Measuring 1, 3-Butadiene and Simulation of its Releasing Method by GIS Application and Cancer Risk Assessment in Tehran in 2019-2020

Background: According to the heavy traffic in Tehran, a high amount of 1, 3-Butadiene (BD) in this city is highly expected. This study estimated the lifetime cancer risk (LCR) attributable to BD in District 9 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 30 points and specified in the area and daily at three different times in four seasons since autumn of 2019 till summer of 2020. 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 9 was evaluated by GIS software. Results: The results showed that the highest and lowest BD concentrations were 2819 and 424 ppb, respectively, in autumn and spring. They were measured in the north and west side of the District 9 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 1×10-6 in the 4 specified groups. So, the amount of LCR in the residents was 790 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.