Estimation of the Increase in Cancer Cases Due to Exposure to Benzene and Ethylbenzene in Air Pollution Scenarios

Background: Air pollution, especially in large cities, is one of the most pressing environmental challenges and is linked to numerous diseases, including cancer. The aim of this study was to estimate additional cancer cases caused by exposure to benzene and ethylbenzene in Tehran. Methods: The data of benzene and ethylbenzene concentration in a three-year period were obtained from the Tehran Meteorological Organization. Carcinogenic risk was calculated based on chronic daily intake (CDI) value. Also, the impact of air pollution control scenarios on risk reduction was estimated using the same approach. Results: The average three-year concentrations of benzene and ethylbenzene were 1.87 ppb and 3.75 ppb, respectively. Under these conditions, the combined carcinogenic risk attributed to these pollutants was 3.76×10-5. Depending on the control scenario, risk reduction ranged from 28% to 72%. To decrease carcinogenic risk below 1×10-6, benzene and ethylbenzene concentrations would need to be reduced to 0.121 ppb and 0.206 ppb, respectively. Conclusion: To reduce the excess cases of cancer attributed to benzene and ethylbenzene, it is necessary to improve gasoline quality, use modern vehicles, and reduce fossil fuel consumption by changes in urban travel patterns.