Abstract
A mercapturic acid attached to the aromatic ring of toluene was for the first time detected in human urine as a metabolite of toluene. Since the metabolism of toluene is usually considered to take place at the side-chain, this gives, besides the biosynthesis of cresols, a further hint of a metabolic conversion of the aromatic system. We examined a group of 33 workers occupationally exposed to toluene, determining the concentrations of toluene in ambient air and in whole blood, o-cresol and hippuric acid in urine and p-toluylmercapturic acid (p-TMA) in urine. All blood and urine samples were collected post-shift. The renal excretion of S-p-toluylmercapturic acid showed highly significant correlations with established parameters of a biological monitoring of toluene. The median ambient air concentration was 63 ppm, ranging from 13 to 151 ppm, the median concentration of toluene in whole blood was 804 μg/l, corresponding to median urinary concentrations for o-cresol of 2.3 mg/l, hippuric acid of 2.3 g/l and p-TMA of 20.4 μg/l. p-TMA was not detectable in urine samples of a control group of 10 non-exposed persons. Both the German Biological Tolerance Values (BAT-values) for toluene in blood (1000 μg/l) and o-cresol in urine (3 mg/l) correspond to a mean p-TMA elimination of ∼50 g/l, and thus are in agreement with each other. According to our results p-TMA reflects internal toluene exposure diagnostically sensitive and specifical. With the developed analytical procedure we determined a median benzylmercapturic acid (BMA) concentration of 190 μg/l in the urine samples of the toluene exposed persons. We also determined a median BMA concentration of 30 μg/l in the control samples of non-exposed persons. However, these results are preliminary and require further confirmation as the reliability of the method was determined only for p-TMA.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 15 July 1997 / Accepted: 24 September 1997
Rights and permissions
About this article
Cite this article
Angerer, J., Schildbach, M. & Krämer, A. S-p -Toluylmercapturic acid in the urine of workers exposed to toluene: a new biomarker for toluene exposure. Arch Toxicol 72, 119–123 (1997). https://doi.org/10.1007/s002040050478
Issue Date:
DOI: https://doi.org/10.1007/s002040050478