Toluene metabolites as biological indicators of exposure
2002; Elsevier BV; Volume: 129; Issue: 1-2 Linguagem: Inglês
10.1016/s0378-4274(01)00472-6
ISSN1879-3169
AutoresCrispin H. Pierce, Yili Chen, Russell L. Dills, David A. Kalman, Michael S. Morgan,
Tópico(s)Body Composition Measurement Techniques
ResumoThe measurement of exhaled and excreted xenobiotics and their metabolites can provide accurate, non-invasive, and time-flexible measurements of internal dose. We analyzed rates of exhaled 2H8-toluene and excreted urinary metabolites from 33 exposures of men to 50 ppm of 2H8-toluene for 2 h at rest. The total dose was distributed as follows: exhaled 2H8-toluene, 13±6.2%; 2H5-hippuric acid, 75±6.4%; 2H7-o-cresol, 0.31±0.22%; 2H7-m-cresol, 0.53±0.44%; and 2H7-p-cresol, 11±3.8%. Interindividual variability was assessed using the coefficients of variation for peak exhalation or excretion rates, and fractions of dose excreted: 2H8-toluene, c.v.=60, 47%; 2H5-hippuric acid, 29, 8.6%; 2H7-o-cresol, 80, 73%; 2H7-m-cresol, 37, 83%; and 2H7-p-cresol, 38, 34%. Excretion rates of the cresols were stable over the first 5 h post-exposure, and o-cresol was determined to be the best urinary indicator of exposure, given the lower background levels of this isomer. The hippuric acid/cresol rate ratios for the first 5 h post-exposure could be described by single exponential terms, and thus provided a means for estimating time since exposure for any finite toluene duration/exposure combination.
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