[Evaluation of occupational exposure to benzene and toluene among workers in two tire manufacturing factories]

ABSTRACT

Semi automated processes of Iranian tire manufacturing factories lead to significant occupational exposures to benzene and toluene compounds. This study was conducted to evaluate the magnitude and risk of workers exposures. Personal monitoring of 100 workers [10 groups] was performed using NIOSH method No.1501 in two tire manufacturing factories in Tehran city.Workplace atmospheric conditions were measured on sampling days. Semi quantitative risk assessment [COSHH] was carried out using questionnaire and respective matrix. Data were analyzed using t-test, correlation coefficient, linear regression and one-way ANOVA. Quantitative values were reported as mean +/- standard error. Age, work experience and atmospheric parameters had no significant statistical difference in two factories. Occupational exposures to benzene and toluene were 1.09 +/- 0.18, 1.88 +/- 0.19 and 2.07 +/- 0.30, 3.20 +/- 0.39 ppm in factories A and B that showed significant increase in B factory and inverse significant correlation with air relative humidity. Exposure to high risk of benzene and medium risk of toluene were 10, 14 and 10, 16 percent of workers in factories A and B, respectively. The correlation between occupational exposure and COSHH assessment was significant. occupational exposure to benzene in tire manufacturing personnel was higher than Iranian standard, therefore, improvement of work conditions using appropriate control measures including automated processes and setting of air relative humidity is recommended. COSHH assessment can be used as a simple, cheap and quick method in workers' health promotion. Control of personnel exposure through ongoing training is imperative