Occupational Risk Assessment of Benzene in Rubber Tire Manufacturing Workers

Tire manufacturing industry has a history of more than half a century in Iran, where 14 thousand workers are employed. The old and semi automated processes equipment, backward technology, and raw materials impurity lead to significant exposures to occupational carcinogens such as benzene. This study was to assessment the exposure and evaluation of cancer risk of benzene exposure in two tire manufacturing factories. One hundred of workers in two target tire manufacturing factories selected as “exposed group”. Personal monitoring was conducted in all process units according to NIOSH 1501 method. Inhalation health risk of benzene exposure was calculated via two assessment models. Data were analyzed using the statistical software of SPSS and quantitative values ​​were reported as mean ± standard error. Occupational Exposure to benzene in 68 percent of workers has exceeded the current exposure limit. The highest level of benzene (5.06 ppm) found in cement making unit. The odds ratio for leukemia was 2.06 times the working population without benzene exposure, as well; the cancer incidence was 16.14 cases per 1000 workers. This study as screening approach is first on addressing the risk assessment of Iranian tire manufacturing workers. The levels of personal exposures and cancer risk were unacceptable and this may provide a basis for developing future control measures.