Evaluating Poly-Aromatic Hydrocarbons in respiratory zone of the asphalt workers in Tehran city

PAHs are organic compounds with benzenic rings that releas from hot asphalt as incomplete combusting. These compounds are one of the major concern in scientific societies، workplace and environment due to their stability، bioaccumulation، carcinogenic and mutagenic effects. Since asphalt workers are exposed to PAHs frequently in their job، in this study it was attempted to evaluate respiratory exposure of asphalt workers to PAHs in their breathing zone. In this study air samples of the asphalt workers were collected in accordance with the NIOSH 5506 method using PTFE filter and XAD-2 adsorbent. The ultrasonic bath and acetonithrile are used in order to extract the analytes from the filter and adsorbent. Also، the samples were analyzed by HPLC-UV. In all samples، Finisher assistance and oilman with 1754. 48 ng/m3، 24. 65 ng/m3 had maximum and minimum exposed to ∑PAH، respectively. Among the PAHs compounds، which asphalt workers exposed to، Naphtalene had the highest concentration. Among different asphalt workers tasks، screedman expoused to PAHs، had a significant difference. Evaluation of Polycyclic aromatic hydrocarbons concentrations in the breathing zone of asphalt workers indicated that exposure to these compounds were below the occupational exposure limits recommended by NIOSH، OSAH، ACGIH and Iranian OEL. Due to the highly carcinogenic potential of some of these compounds and absence of occupational exposure limits for these compounds، likes Chrysene and Benzo (a) Anthracene، it is strictly recommended to employ engineering controls and using suitable PPEs. This study also indicated that the exposure to PAHs in the most asphalt workers tasks had significant differences، and it can be due to proximity of the workers to the source of hot asphalt and also exposure to the exhaust gases that releasesd from the construction machinery.