自來水中的三鹵甲烷對於健康之影響，藉由健康風險值之計算，以了解臺南地區居民飲用自來水所承受之健康風險。
本研究使用台灣自來水公司第六區管理處水質檢驗資料，加以統計分析，並且利用美國環保署健康風險評估步驟，以評估臺南地區各淨水場供水之三鹵甲烷健康風險值。研究結果顯示臺南地區之總三鹵甲烷中以三氯甲烷佔最多，在暴露途徑分析發現以吸入為最主要之途徑，貢獻度佔81％，皮膚接觸的貢獻度佔最小只有8％。臺南地區各供水區之致癌健康風險值在3.25×10-6~4.74×10-6之間，致癌健康風險在安全範圍內。非致癌風險評估結果，臺南地區各淨水場之非致癌風險危害指數均遠小於1，因此非致癌健康風險在可接受範圍內。 The purpose of this thesis is to evaluate the cancer risk of Trihalomethanes (THMs) in drinking water as well as understand health risk of THMs on human in Tainan.
The thesis statistically analyzed the data of water quality, which is taken from Taiwan Water Corporation Sixth branch since 2008 to 2010, and evaluated the health risk value of THMs in every treatment plant of Tainan with theory of Health Risk Assessment of U.S.EPA.
Results of health risk assessment of THMs show that inhalation is the major route of risk exposure, which contributes 81% of the cancer risk. The dermal contact only contributes about 8% of the cancer risk. Among those four components of THMs, Trichloromethane (TCM) had higher detected concentrations. The averaged THMs health risk value in Tainan of drinking water is 3.25�10-6~4.74�10-6, cancer health risk of THMs in Tainan city is lower. Non-carcinogenic health risk for THMs is far below human tolerance levels ,with risk hazard index much less than 1, and non-carcinogenic health risk is in an acceptable range.
