Risk Assessment on Benzene Exposure among Gasoline Station Workers

Benzene is a human carcinogen presented in gasoline (1% by volume). It is also found in vehicle exhaust. The aim of this study was to assess the health risk of inhalation exposure to benzene among gasoline station workers. The ambient benzene concentration was measured by personal sampling from 150 gasoline station workers (137 fueling workers and 13 cashiers). Additional data of working characteristics were collected by interviews and on-site observations. All workers were non-smokers and passive smoking was limited. Risk assessment of inhalation exposure was determined using the United State Environmental Protection Agency (USEPA),and showed a high risk of adverse health effect (Hazard Quotients (HQ) >1) in 51.33% of workers. The cancer risk was increased from 1.35 × 10^-8 to 1.52 × 10^-4, and 70.67% of the workers had a lifetime cancer risk (>Inhalation Unit Risk (IUR): 2.2 × 10^-6). A significantly higher risk was found in fueling workers compared to cashiers, and in workers at gasoline stations in inner-city zones (suburban and urban), compared to rural zones. All risk estimations were based upon a single measurement in an eight hour working period, which was assumed to be the average shift length for all working days in a year (250 days). The increased health risk suggests that there should be health surveillance for workers in order to protect them from exposure to benzene. In addition to benzene, the volatile organic compounds (VOCs) present in gasoline may influence health outcomes.