| Summary: | 碩士 === 長榮大學 === 職業安全與衛生研究所 === 97 === In this study methanol exposure of 4 gluing workers in a tempered glass manufacturing factory was measured for 6 workdays. Air measurements and biological specimens including exhaled breath, saliva and urine were collected. In order to estimate the background level of methanol in a human body, 25 workers without any organic solvent exposure were recruited to provide their breath and urine samples for methanol measurements. The exposure measurements included: (1) to monitor the airborne concentration of methanol in the work environment by using Figaro TGS-822 sensor with a HOBO data logger; (2) to quantify the amount of methanol in the pre- and post-shift urine samples; (3) to measure the methanol concentration of the salivary sample taken in each hour during a workday; (4) to measure the methanol concentration of the breath sample taken in each hour during a workday. All the collected air, urine and breath samples were analyzed by using gas chromatography /mass spectrometry (GC/MS) with a headspace system. The objectives of this study were: (1) to evaluate the association between the breath methanol concentration and the methanol concentration respectively measured from the air, urine and salivary samples; (2) to compare the mean and variability of methanol concentrations measured from breath and salivary samples; (3) to evaluate the correlation between the methanol concentrations measured by breath and salivary samples based on experiments of skin absorption of methanol. The results of exposure data analyses found that the methanol concentrations measured by HOBO and silica gel tubes showed a significant association (r=0.47, p<0.01); the methanol concentrations measured from breath samples and HOBO air measurements did not have a significant association (r=0.22, p=0.14). This insignificant association was probably due to the interference of methanol skin absorption through the bare hands when the workers used methanol to clean the surface of glass. The correlation between the methanol concentrations measured from breath and urine samples was close to the margin of statistical significance (r=0.39, p=0.075). Because the half-life of methanol in urine is short, it is not suitable to evaluate 8-hour time-weighted average methanol exposure by measuring a post-shift urine sample. From the methanol measurements of breath and salivary samples in the experiments of methanol skin absorption, it was found that the methanol measurements showed a significant correlation (r=0.81, p<0.01). The results of data analysis of both field exposure measurements and skin exposure experiments indicated that the skin absorption should not be ignored for methanol exposure assessment. It is required to have more in-depth exploration of skin absorption of methanol exposure in future studies.
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