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

BACKGROUND 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. OBJECTIVE 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. METHODS 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). RESULTS 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. CONCLUSION Exposure to benzene would cause bone marrow depression presenting as drop in hemoglobin, hematocrit and eosinophil counts.