There were some limitations in the current study regarding
data interpretation. First, we did not measure the ambient air levels
of VCM or EDC in any subject during our sampling period.
Further, we cannot provide direct evidence regarding the sources
of TDGA in the school-aged children. Secondly, although we collect urine samples of our subject at the same time of individual elementary school, we did not collect all the urine sample at the same day. Third, the wind direction during our sampling period, autumn and spring, was similar, and we used repeated sampling for TDGA in a subgroup of participating children to compare differences in TDGA exposure between school time and vacation. Fourth, we did not utilize a detailed food questionnaire to evaluate the possible effects of food products or containers. Fifth, we could not rule out potential exposure from drinking water. Drinking water might contain VCM released from contact with polyvinyl pipes, from
contaminated underground water, or a microbial degradation
product of trichloroethylene in groundwater. Lastly, the air inside
new cars could emit trace levels of VCM, mainly from the new
plastic parts. However, it is less likely that this was the major
source for urinary TDGA in our subjects.
資料來源 http://www2.fpg.com.tw/html/news/news_images/5IIEYQ2DTCL_04.pdf