WET DEPOSITION OF HYDROCARBONS IN THE CITY OF TEHRAN-IRAN

Air pollution in the city of Tehran has been a major problem in the past three decades. In the present investigation rain water samples was collected and analyzed for Benzene, Toluene, Ethyl Benzene and Xylenes (BTEX) as well as fuel fingerprint in two range of gasoline (C5-C11) and diesel fuel (C12-C20). In addition the concentration of 16 polycyclic aromatic hydrocarbons (PAHs), all on the United States Environmental Protection Agency (US EPA) priority pollutant list, was studied. Among BTEX, Toluene shows the highest concentration of 108±61, the maximum concentration of PAHs was for Fluoranthene with 204±152 mg/L. Both the gasoline and diesel fuel were also present in the collected rain water at concentrations of 190 ppb and 950 ppb respectively. The study demonstrated that over 4.6 tons of PAHʹs, 1.2 tons of BTEX, 1.8 tons of gasoline and 9.1 tons of diesel fuel are transported to soil and surface waters by this wet deposition.