Journal of North Khorasan

Abstract Background and Objectives: Monoaromatic compounds because of the potential carcinogenicity and participation in photochemical smog are the most important environmental pollutants, especially in mega cities. This study was conducted to assess monoaromatic compounds in Tehran in 2011. Materials and Methods: This study was a cross sectional. Benzene, toluene, and xylene isomers (BTX) and ethylbenzene were Measured in Tehran by PhoCheck PID Detector in morning, noon, afternoon. Results: The highest concentrations were recorded by benzene (6.95 ppb), which had a high potential for carcinogenesis. Comparing the xylenes to toluene and benzene indicated that combustion, but not fuel evaporation, is the major common source. Monoaromatic peak was observed at noon, which was indirectly related to the heavy traffic at this time. Conclusion: Fuel combustion in vehicles in Tehran is main source of production and releasing of monoaromatic compounds.