personal exposure to polycyclic aromatic hydrocarbons in newsagents in tehran, iran.

vehicle exhaust is a major source of exposure to polycyclic aromatic hydrocarbons (pahs) found in the urban atmosphere. newsagents usually work close to heavy traffic flow. the purpose of this study was to assess the breathing zone exposure of newsagents to pahs found in the urban atmosphere of tehran city during summer and autumn seasons and comparing the levels of exposure in both seasons.fifteen non-smoking newsagents were randomly selected from north, south, east, west, and center of tehran. particle and gas phases pahs were collected on polytetrafluoroethylene (ptfe) filter and xad-2 adsorbent. gas chromatography-mass spectrometry (gc/ms) was used to determine pahs concentrations in newsagent's breathing zone samples.the highest and lowest values of exposures during summer and autumn in all sampling stations were recorded for benzo[a]anthracene and benzo[ghi]perylene, respectively. mann-whitney test results showed that seasonal variation had significant influence on concentrations of all studied pahs (p= 0.001) except benzo[ghi]perylene (p= 0.089). an increase in concentrations of pahs was observed in autumn.the workers of the newsstands in the south area of tehran city were experiencing higher levels of exposures to pahs. newsagents' breathing zone exposures to pahs during the cold period were two to three folds higher than those during the warm period were. the levels of exposures in all sampling stations were below the osha and niosh's recommended exposure limits.