Trans, Trans-Muconic Acid as a Biomarker of Occupational Exposure to High-Level Benzene in China

Objective: The work aimed to study the potential correlation between the high-level benzene exposure and its urinary metabolites S-phenylmercapturic acid (SPMA) and trans, trans-muconic acid (t,t-MA) in Chinese shoe-making workers. Methods: Individual benzene-exposed levels were determined by gas chromatography analysis, urinary t,t-MA, and urinary SPMA were determined by high performance liquid chromatography-an ultraviolet detector and liquid chromatography/electrospray tandem mass spectrometry method, respectively. Results: The concentration of benzene ranged from 2.57 to 146.11 mg/m(3). And the correlation between benzene and t, t-MA was significantly higher than that of SPMA at the postshift, for example, the correlation coefficient was 0.905 and 0.537 for t,t-MA and SPMA, respectively. Moreover, The relative internal exposure index of t,t-MA (0.28 mg/g Cr: mg/m(3)) was more similar to the data supplied by American Conference of Governmental Industrial Hygienists compared to the index of SPMA (0.025 mg/g Cr:mg/m(3)). Conclusions: t, t-MA appeared to be a more specific biomarker than SPMA at high-level benzene exposure.