代谢
TdGA是人体尿液中检出的VCM的主要代谢物。尽管尿液中TdGA与VCM暴露有关，但尿液中TdGA与空气中低水平VCM的关系尚不清楚。我们对16名聚氯乙烯制造工人进行了问卷调查，以获取详细的职业和生活方式历史。对每位工人进行了个人空气中的VCM监测，并计算了VCM暴露的时间加权平均值。还评估了每个工人在工作班次结束时和下一个班次开始时的尿液TdGA水平。尿液分析显示，下一个班次开始时的TdGA水平高于该班次结束时的水平。空气VCM暴露量>5 ppm的工人尿液TdGA水平显著高于暴露量<5 ppm的工人（P<0.05）。尿液TdGA对空气VCM的最佳回归拟合为Y=1.06 + 0.57X，其中X为空气VCM浓度，Y为尿液TdGA浓度（r2=0.65，P<0.01）。我们得出结论，尿液TdGA水平最好在下一个班次开始时检测，并且当工人暴露的空气VCM水平>5 ppm时，它可以作为聚氯乙烯工人的暴露标志。
Thiodiglycolic acid (TdGA) is the major metabolite of vinyl chloride monomer (VCM) detected in human urine. Although urinary TdGA has been reported to be associated with ambient VCM exposure, the relationship between urinary TdGA and a low level of air VCM is not clear. Questionnaires were administered to 16 polyvinyl chloride manufacturing workers to obtain a detailed history of occupation and lifestyle. For each worker, personal air monitoring for VCM was performed and a time-weighted average for VCM exposure was calculated. The urinary TdGA levels at the end of a work shift, and at the commencement of the next shift, were also assessed for each worker. Urine analysis revealed that TdGA levels at the beginning of the next shift were higher than those at the end of that shift. Workers experiencing a VCM exposure >5 ppm in air revealed a urinary TdGA level significantly greater than those experiencing a VCM exposure of <5 ppm (P<0.05). The best fit of regression for urinary TdGA on air VCM was Y=1.06 + 0.57X for urine collected at the commencement of the following work shift, where X is the air VCM concn and Y is the urinary TdGA concn (r2=0.65, P<0.01). We conclude that the urinary TdGA level is best detected at the commencement of the next shift and that it can be used as an exposure marker for polyvinyl chloride workers when the air VCM level to which they are exposed is >5 ppm.
来源:Hazardous Substances Data Bank (HSDB)
