Assessment of Exposure to Benzene Among Gasoline Station Workers in Thailand: Risk Assessment Matrix Methods

This study of risk assessment of gasoline station workers was performed by using the following three models: the occupational safety and health (OSH) risk assessment aligned with ISO 45001, the biomatrix of health risk, and the benzene risk matrix assessment for gasoline station workers. Levels of inhaled air benzene and urine tt-muconic acid (tt-MA) were measured using samples collected from 151 gasoline station workers. Opportunity levels of benzene exposure were obtained by multiplying the frequency of benzene exposure by the levels of tt-MA, the inhaled benzene concentration levels, or the likelihood levels from contributing risk factors at gasoline stations. The final risk scores were calculated by multiplying the opportunity levels by the severity based on the adverse symptoms of benzene toxicity experienced by workers. A checklist regarding risk factors contributing to benzene exposure was used to collect data on occupational safety performance. The potential health risk was at an unacceptable level for 66.23%, 75.50%, and 60.26% of workers according to the OSH risk, the biomatrix of health risk, and the benzene risk matrix model, respectively. There was a significant linear relationship between the risk levels indicated by the three matrix models (r > 0.6, p < 0.001). These findings demonstrate that alternative risk assessments can be provided and simply used for preventive action against health hazards from benzene exposure in risk management programs.