Survey of the In-Cabin Benzene Concentration in Yazd Yavi- cabs Using Soli Phase Microextraction Technique

To establish a method for determination of in-cabin benzene and evaluate the occupational exposure, a cross-sectional study was conducted. In this descriptive study, 30 taxi-cabs were selected and the concentrations of benzene was measured in stopping and driving conditions using solid phase microinstruction (SPME) method. The overall average concentration of benzene in all brands was 905 and 309µg/m3 under stopping and driving conditions, respectively. Under stopping condition, the highest and lowest average concentrations were 3200 and 122µg/m3 respectively. After 15 minutes of driving, the levels lowered to 1000 and 57µg/m3, respectively. The concentration of benzene decreased rapidly and significantly, after 15 minutes of driving with opened windows (p<0.05). In both stopping and driving conditions, the concentration of benzene in taxi-cabs with more than six months life time (1138 and 393µg/m3) was higher than those of less than six month life time (671 and 225µg/m3). However, no significant variation was observed. The concentration of benzene measured herein in this study, markedly exceeds the proposed indoor benzene NHMRC standard. The results indicate that opening the windows before driving reduces the exposure of drivers to benzene. The result of this study could also be useful for further monitoring program of in-vehicle air quality.