Background and Objective: Air pollution is one of the most important environmental problems. Asphalt plants are the sources of air pollutants, especially particulate matters. The purpose of this study is to investigate the emission rate of PM_2.5 and PM₁₀ emitted from asphalt plants in the southwest of city of Tehran, also the present study was conducted to estimate the dispersion of particulate matters concentrations on surranding areas of a mining complex and city of Tehran.
Methods: This descriptive-cross sectional study was performed on the asphalt plants in a mining complex in the southwest of Tehran. In this study, at first the concentrations of PM_2.5 and PM₁₀ emitted from asphalt plants located in the southwest of Tehran were calculated using emission factors suggested by the US Environmental Protection Agency. Then, the dispersion of particulate matters concentrations was estimated on the surrounding areas of the mining complex with a radius of 50 km using the AERMOD model for the average times of 24 hours and annually using emission rate, meteorology and topography data. At last, the simulated concentrations were compared to EPA and WHO standards.
Results: The maximum particulate matter concentrations are in the mining complex, and is gradually reduced by moving away from it. Dispersion of particles in the directions of dominant winds has been uniform. The maximum PM_2.5 and PM₁₀ concentrations have been estimated about 1 µg/m³ and 2 µg/m³ in Qods, 1 µg/m³ and 2 µg/m³ in Shahriyar, 0.6 µg/m³ and 1 µg/m³ in Andisheh and 0.2 µg/m³ and 0.4 µg/m³ in Tehran respectively in a 24-hour period. The amount of PMs that reached the west of Tehran continues to the eastern regions of the city. PMs concentrations were not significant in the average annual period.
Conclusion: Although dust emission rate from asphalt plants in the southwest of Tehran is acceptable, but it affects on the air quality in the surrounding areas of the mining complex and to some extent in Tehran. The cumulative effects of different industries can increase the potential health risks in the communities vicinity of this mining complex.