Risk Assessment of Exposure to 1,3-Butadiene in Possible Air Pollution Control Scenarios in Tehran Using Monte Carlo Simulation

Background: Exposure to 1,3-butadiene leads to an increase in the carcinogenic risk and other related diseases. This study aimed to assess the carcinogenic and health risks of exposure to ambient 1,3-butadiene emitted from various sources in Tehran. Methods: For this purpose, sampling and data analysis were done in 30 monitoring stations in Tehran in 2024. In addition, the contribution of motor vehicles to the emission of 1,3-butadiene was estimated by IVE and AERMOD. Also, the Carcinogenic Risk (CI) index and Health Quotient (HQ) were used to evaluate carcinogenic and non-carcinogenic risk affected by the current concentration and four other scenarios. Results: The results showed that the average of 1,3-butadiene concentration caused by motor vehicles and stationary sources was calculated to be equal to 2.1E+1 and 7.86E+1 µg/m3 , respectively. The detected concentration was 4 times higher than the estimated concentration, indicating a significant concentration of contamination. In the best scenario, the pollutant concentration was reduced by 48%. The carcinogenic risk in the current conditions and the best scenario was 7.48E-03 and 4.06E-03, respectively, which were still much higher than the acceptable level. Conclusion: Scenarios of reducing the pollutant concentration made the non-carcinogenic risk for adults below the acceptable level. Therefore, modifying fuel consumption patterns, reducing fossil fuel consumption by implementing energy-saving measures in buildings and supporting the increase in electric vehicles, and monitoring air pollution control systems in industries are the main suggestions of this study to reduce the health risks of 1,3-butadiene.