Occurrence, spatial distribution, seasonal variations, potential sources, and inhalation-based health risk assessment of organic/inorganic pollutants in ambient air of Tehran

The present study evaluated the concentrations, spatial distribution, seasonal variations, potential sources, and risk assessment of organic/inorganic pollutants in ambient air of Tehran city. Totally, 180 air samples were taken from 9 sampling stations from March 2018 to March 2019 and were analyzed to determine the concentrations of organic pollutants (BTEX compounds and PM2.5-bound PAHs) plus inorganic pollutants (PM2.5-bound metals and asbestos fibers). The results revealed that the mean concentrations of n-ary sumation PAHs, BTEX, n-ary sumation heavy metals, and asbestos fibers were 5.34 ng/m(3), 60.55 mu g/m(3), 8585.12 ng/m(3), and 4.13 fiber/ml in the cold season, respectively, and 3.88 ng/m(3), 33.86 mu g/m(3), 5682.61 ng/m(3), and 3.21 fiber/ml in the warm season, respectively. Source apportionment of emission of the air pollutants showed that PAHs are emitted from diesel vehicles and industrial activities. BTEX and asbestos are also released mainly by vehicles. The results of the inhalation-based risk assessment indicated that the carcinogenic risk of PAHs, BTEX, and asbestos exceeded the recommended limit by The US environmental protection agency (US EPA) and WHO (1 x 10(-4)). The risk of carcinogenesis of heavy metal of lead and chromium also exceeded the recommended limit. Thus, proper management strategies are required to control the concentration of these pollutants in Tehran's ambient air in order to maintain the health of Tehran's citizens.

Automated summary

The study evaluated the concentrations, spatial distribution, seasonal variations, sources, and risk assessment of organic/inorganic pollutants in the ambient air of Tehran city. Results showed that the pollutants mainly come from diesel vehicles and industrial activities, posing potential health risks for the citizens.