Occupational exposure to benzene and changes in hematological parameters and urinary trans, trans-muconic acid

For its toxicity, benzene exposure is one of the main health concerns for high risk occupations like gasoline station workers. However, there is little knowledge about the effect of benzene metabolites on hematological parameters. To evaluate the correlation between the urinary level of trans, trans-muconic acid [t, t-MA], a benzene metabolite, and some hematological parameters in gasoline workers. We studied 102 gasoline station workers from 11 gasoline stations in Pathumwan district, central area of Bangkok, Thailand. Their blood and urine samples were analyzed for some hematological parameters and urinary t, t-MA analysis by high performance liquid chromatography [HPLC]. We found an inverse correlation between urinary t, t-MA concentration and hemoglobin level [r = 0.281, p<0.05], hematocrit [r = 0.264, p<0.05]. Those with higher urinary t, t-MA had a significantly [p<0.05] lower eosinophil counts than those with lower exposure. No significant correlation was found between urinary t, t-MA level and other white blood cell parameters and platelets count. Exposure to benzene would cause bone marrow depression presenting as drop in hemoglobin, hematocrit and eosinophil counts

Occupational exposure of gasoline station workers to BTEX compounds in Bangkok, Thailand

Gasoline station workers are exposed to volatile organic compounds such as benzene, toluene, ethylbenzene and xylene [BTEX]. To determine the level of exposure to BTEX compounds among gasoline station workers and measure the roadside concentrations of these compounds in the inner and outer areas of Bangkok, Thailand. 49 workers at 6 gasoline stations in the inner and outer areas of Bangkok participated in this study. Samples of ambient air were collected from the area near gas pumps at each station and at the roadside in front of the gas stations by charcoal tubes. All samples were analyzed for BTEX compounds by gas chromatography-flame ionized detector [GC-FID]. The mean BTEX concentration in gas stations was slightly higher than that of the roadside; there was no significant difference in the concentration between inner and outer areas. The mean lifetime cancer risks for workers exposed to benzene and ethylbenzene for 30 years were estimated at 1.75x10-4 and 9.55x10-7. The estimated hazard quotients for BTEX compounds were 0.600, 0.008, 0.007 and 0.002, respectively. The most prevalent symptoms of workers were headache [61%], fatigue [29%] and throat irritation [11%], respectively. Exposure to benzene and toluene was significantly associated with fatigue [p<0.05]. Exposure to BTEX compounds would increase the risk of cancer in gasoline station workers. Exposure to benzene and toluene may cause fatigue