| 摘要: | 為維護國人身體健康，飲用水需要以含氯的物質消毒，導致飲用水中含有害的揮發性的有機物。在國內飲用水水質標準中也對其中九種物質加以管制，管制標準的設定乃參考先進國家之水質標準。因此本研究之目的在於實地量測健康成年人的呼吸量及收集他們飲水量與洗澡時間等資料以根據現行飲用水中揮發性有害物質進行化合物的致癌風險評估，此結果將可供政府未來修訂飲用水中有害物質管制標準之參考。 首先於89/06-89/08於中部某教學醫院體檢處，以手提式肺功能機量測健康成年人每分鐘的呼吸量及以問卷調查方式收集相關每個人的飲水量與洗澡時間等資料。接著利用這些數據針對國內飲用水法規所管制的苯、四氯化碳、1,1二氯乙烯、1,2 —二氯乙烷、三氯乙烯與氯仿等六種揮發性致癌物質進行風險評估，根據簡易化合物風險評估方法，評估在這些物質的管制標準、現有的國內檢測數據、與分析方法的偵測極限下，淋浴期間經呼吸暴露吸入性之致癌風險。 根據收集與量測的數據分析結果，得到樣本中健康成年人平均體重為60.5公斤與國人平均體重非常接近，平均飲水量2.5公升/天、平均呼吸量12.7m3/天、平均洗澡時間12.7分鐘等。針對飲用水中六種揮發性致癌物質，計算淋浴期間經呼吸暴露之致癌風險；(1)以現行管制標準推估水溫於25℃時致癌風險為2.89 ×10-5；(2)若以這些物質偵測極限推估水溫於25℃時致癌風險為1.71 ×10-6；(3)若以這些物質檢測結果最大值推估水溫於25℃時致癌風險為7.39 ×10-6。 在此建議國人在現有飲用水的管制標準下盡量不要生飲，也建議環保署對飲用水中揮發性有害物質的管制標準，應該適時的考慮降低管制標準，以維護國人的健康。; In order to protect consumers from waterborne diseases, drinking water was usually disinfected by chlorination. The adverse health effects of contaminants and disinfection byproducts in drinking water have been of concerns. Currently, Taiwan EPA regulates 50 contaminants in drinking water. The values of maximum contaminant levels (MCLs) in drinking water were adopted from developed countries. The objective of this study was to collect domestic data for assessing cancer risk for volatile carcinogens in drinking water. In order to collect domestic data, healthy adults were selected from the health examination clinic at Taichung Hospital from 89/06 — 89/08. Before the inhalation rate was measured using a portable and computerized spirometer, each subject was asked to complete questionnaires designed to collect information related to quantity of drinking water consumption, shower time, and time spent at home and et al. Then, these data were integrated to assess cancer risk from inhalation exposures during showering for benzene, carbon tetrachloride, vinyl chloride, 1,1-dichloroethylene, 1,2-dichloroethane, and trichloroethylene by following the simple mixture risk assessment method. The results from our field study and survey are: mean drinking amount：2.5 L/day, mean body weight：60.5㎏, mean tidal volume: 12.7 m3/day, and mean shower time: 12.7 min. Cancer risk from inhalation exposures to VOCs in drinking water during showering are: 2.89 ×10-5 based on the MCLs (25oC) issued by Taiwan EPA, 1.71 ×10-6 based on the detection limits of analytic methods for contaminants (25oC) in drinking water, and 7.39 ×10-6 based on the maximum concentrations (25oC) measured for regulated contaminants in drinking water. These results suggest that Taiwan EPA may consider to low the current MCLs for contaminants in drinking water in order to protect the consumers from adverse health effects. |
