The exposure and occupational health of workers exposed to toluene
Date Issued
2006
Date
2006
Author(s)
Chou, Jui-Shu
DOI
zh-TW
Abstract
Toluene is a widely used solvent in Taiwan. It is a human central nervous system (CNS) depressant. Long-term occupational exposure to toluene is associated with liver and kidney damage, and hearing loss in humans. A number of studies have recognized dermal absorption of toluene. Therefore, prevention of dermal absorption might be required for occupations which involve toluene exposure.
This study was comprised of three parts. Part I: A method based on liquid chromatography (reversed phase)-electrospray (negative) ionization-tandem triple quadrupole mass spectrometry (LC-ES(–)-MS/MS), in the multiple reaction monitoring mode, was developed for determination of urinary benzylmercapturic acid (BMA). Isotope dilution through introduction of 13C6-labeled BMA was employed as an internal standard, achieving intra- and inter-run precision ranges of 2.32%–2.95% and 2.24%–4.97%, respectively. The calibration curve obtained with BMA-spiked blank human urine was linear from 0.5–120.0 ug/L; the correlation coefficient of the calibration curve was 0.999. The method limit of quantification was 0.5 ng/mL; mean BMA recovery was 97.56%.
Part II: Exposure via respiratory and dermal routes was assessed on an individual basis for 109 workers employed in eighteen factories which manufactured adhesive tape who were directly exposed to toluene. Respiratory exposure was determined by breathing-zone sampling for a full-work shift, and dermal exposure was assessed on nine skin areas (the palms, forearms of both hands and the paravertebral area of the seventh cervical spine process) by a hand wipe sampling method. Each worker provided a post-shift urine sample and urinary hippuric acid, o-cresol and BMA were measured. Toluene concentrations on the nine skin areas showed no statistical differences. In multiple linear regression tests, airborne toluene and toluene on the skin remained significantly (P<0.05) associated with urinary happuric acid/creatinine (g/g),o-cresol (ug/L), o-cresol/creatinine (ug/g), o-cresol/specific gravity (ug/L), BMA (ug/L), BMA/creatinine (ug/g) and BMA/specific gravity (ug/L).
Part III: A total of 283 workers in adhesive-tape production factories in Taiwan were recruited for this study. Each participant read and signed consent forms. The participants had clinical examinations which they were different included red blood cell count, hemoglobin, hematocrit and alanine aminotransferase. Comparisons were made among the exposed (noise and toluene), contrast (noise) and control groups (administrative personnel, unexposed) and between genders. The average noise exposure in the working environment was lower than 90 dBA, but workers who were exposed to both noise (82.8±2.6 dBA) and toluene (35.8±25.2 ppm) had enhanced hearing loss.
The present study established a sensitive, specific and reliable testing method to determine urinary BMA in urine samples collected from workers who had been exposed to toluene. We found that dermal exposure provides a substantial contribution to the total body burden of toluene, and workers experience hearing loss after long-term exposure to toluene.
Subjects
膠帶製造業
甲苯
皮膚吸收
生物偵測
健康危害
adhesive-tape production factories
toluene
dermal absorption
biological monitoring
health effect
SDGs
Type
thesis
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