Exposure to benzene, toluene, ethylbenzene, xylene, formaldehyde, and acetaldehyde in and around gas stations in Japan

Abstract

We investigated the personal exposure of gas station employees to benzene, toluene, ethylbenzene, xylene, formaldehyde, and acetaldehyde at three full-service gas stations in Okayama, Japan. We also assessed both the indoor (offices) and ambient background concentrations. The personal exposure, indoor, and ambient concentrations of benzene were 57.3, 6.11, and 1.31 μg/m3, respectively, in spring and 17.0, 2.04, and 0.603 μg/m3, respectively, in winter. Those for toluene were 196, 25.8, and 2.66 μg/m3, respectively, in spring and 30.6, 5.31, and 1.23 μg/m3, respectively, in winter. The personal exposure concentrations of benzene, toluene, ethylbenzene, and xylene for a gas station employee were significantly higher than those for indoors and the ambient air. However, the personal exposure, indoor, and ambient concentrations of formaldehyde were 5.08, 10.1, and 4.29 μg/m3, respectively, in spring and 11.6, 24.1, and 6.04 μg/m3, respectively, in winter. The indoor concentrations of formaldehyde were significantly higher than both the personal exposure concentrations for gas station employees and the ambient concentrations. The excess lifetime cancer risk from benzene exposure was estimated to be 2.22 × 10−5, 2.43 × 10−6, and 2.56 × 10−7 for full-service gas station employees, self-service gas station employees, and self-service gas station users who are assumed to use the station once a week, respectively. Assuming the occupational exposure to toluene, ethylbenzene, and xylene at the gas station were comparable to the maximum 2-h average exposure levels in the present study, the total hazard quotient for non-carcinogenic risk was calculated to be much lower than 1 (2.72–5.56 × 10−3) based on the TLV-TWA (8-h).