Urine trans,trans-muconic acid as a biomarker for benzene exposure in gas station attendants in Bangkok, Thailand.

The toxicity of benzene, a chemical used in many industrial processes, involves bone marrow depression and leukemogenesis and is associated with damage to multiple classes of hematopoietic cells and hematopoietic functions. Environmental exposure to benzene causes an increased body burden, which is reflected in several biomarkers, eg, urine trans,trans-muconic acid (ttMA). Associated with the industrialization of Thailand, a developing country in Southeast Asia, workers in many occupations have acquired substantial risks of benzene exposure. In this study, benzene exposure was monitored by high-performance liquid chromatography (HPLC) of urine ttMA in 79 persons, including 49 controls and 30 gas station attendants. In controls, urine ttMA concentration averaged 0.12 (SD +/- 0.03) mg/g creatinine; in gas station attendants, urine ttMA concentration averaged 4.00 (SD +/- 12.49) mg/g creatinine (p < 0.05). Based on these findings, wider use of urine ttMA determination is recommended as a biomarker for occupational exposure to benzene.