Exposure Pathways of Polychlorinated Biphenyls in Er-Jn River and Activities in Environmental Media Measured with Solid Phase Microextraction

雖然已有釵h研究指出二仁溪中底泥及魚體內之多氯聯苯(polychlorinated biphenyls, PCBs)濃度甚高，受到介質高吸附能力之影響，此污染物在環境中之流布方向，並非直接受其濃度高差所控制，活性才能決定多氯聯苯於二仁溪之流布途徑。而必須確立暴露途徑，始能估計當地居民食用二仁溪豆仔魚之健康風險。本研究利用固相微量萃取(solid phase microextraction, SPME)之概念，建立以聚二甲基矽氧烷(polydimethylsiloxan, PDMS)塗覆之光纖量測環境介質中多氯聯苯活性之方法。由於可以正確測量PCBs在水中之活性，故本實驗可以最少之干擾而得到較之以往更精確PDMS－水平衡分配常數(Kpw)、有機質－水平衡分配常數(Kom)及生物濃縮因子(BCFL)。 在排除玻璃吸附之影響後所得之logKpw與logKow具良好之線性關係(logKpw = 0.89logKow + 0.36, R2 = 0.92)。文獻中Kpw值較低之原因，應為其忽略玻璃吸附之影響而造成。 logKom與logKow之關係亦呈現與文獻類似之線性關係(logKom = 1.17logKow – 1.03, R2 = 0.86)，唯本實驗之logKom稍高於文獻。分布於5.88至8.53之logBCFL與logKow亦呈線性關係(logBCFL = 1.07logKow + 0.30, R2 = 0.77)，而非一些文獻中所言之當logKow > 6時為非線性關係或當logKow > 7.5 則logBCFL開始下降。前述之差異或鳥犰]於天然水體中均含有不易分離之懸浮顆粒或溶解性有機質，使傳統方法測得疏水性有機物之溶解濃度偏高，並導致低估Kom及BCFL之值。 多氯聯苯之活性研究顯示魚體、水及表層底泥處於約略平衡狀態。暴露途徑為由深層底泥至表層底泥，再至魚體，最後因人類攝食而進入人體。終生致癌風險為3.4×10-6，危害商數為0.40。兩者皆顯示二仁溪之風險潛勢值得注意。Researches have shown high concentration of polychlorinated biphenyls (PCBs) in sediment and fish in Er-Jen River. The exposure pathways of PCBs are forward human bodies of concern. Infact, activity in each environmental phase governs PCBs’ migration directions. Understanding the activity of each compartment in the estuary, including sediment, water, and fish, is important for assessing the potential health risk residing near Er-Jen River. This study is aimed to establish a solid phase microextraction (SPME) method to measure the activities of PCBs in environmental media by using polydimethylsiloxan (PDMS) coated optical fibers. Partition coefficients of PDMS to water and organic matter to water (Kpw and Kom), and bioconcentration factor (BCFL) could be determined more accurately in this study with less artifacts and were compared with those from the literatures. Without the interference of adsorption on glass wall, logKpw obtained from this study shows a linear relationship with logKow (logKpw = 0.89logKow + 0.36, R2 = 0.92) even for PCBs with high chlorine number. The lower Kpw value from literatures might be due to neglecting the effect of glass wall’s adsorption. logKom increases linearly with logKow (logKom = 1.17logKow – 1.03, R2 = 0.86), however, is higher than the logKom reported in the literature. LogBCFL ranges from 5.88 to 8.53 and also has a linear relationship with logKow (logBCFL = 1.07logKow + 0.30, R2 = 0.77), while some literatures says logBCFL becomes nonlinear with logKow as logKow > 6 and even decreases as logKow > 7.5. These discrepancies might be resulted from overestimating the nature water’s concentration and underestimating BCFL, especially for substances with higher logKow values possibly, due to the nonseparable sorbing compartments in the aqueous phases. PCBs’ activities in fish, water, and surface sediment showed that they were about in equilibrium state. Pollutants were going from deeper sediment to surface layer sediment, fish, and finally uptaken by human. Estimated life time cancer risk of a resident in the estuary area is 3.4 10-6 and hazard quotient is 0.40.目錄……………………………………………………….……………...I 表目錄…………………………………………………………………VI 圖目錄………………………………………………………………...VII 第一章 緒論………………………………………….……………...1-1 1.1 研究緣起………………………………………………………..1-1 1.2 研究動機及目的………………………………………………..1-2 1.3 研究內容………………………………………………..............1-3 第二章 研究背景與原理………………………………………….2-1 2.1 二仁溪之背景及國內相關研究………………………………..2-1 2.1.1 二仁溪之背景……………………………………………...2-1 2.1.2 國內相關研究……………………………………………...2-2 2.2 多氯聯苯簡介…………………………………………………..2-3 2.2.1 多氯聯苯物化特性及其於工業上之應用………………...2-3 2.2.2 多氯聯苯之毒性…………………………………...............2-5 2.2.3 多氯聯苯於環境中之宿命………………………………...2-6 2.2.4 多氯聯苯之人體暴露途徑及暴露劑量……….…………..2-7 2.3 物質於環境中流布方向之預測………………………………..2-8 2.3.1 化學勢能、逸壓與活性……………………………………2-8 2.3.2 利用線性模式求得環境介質中之物質活性….................2-10 2.3.3 利用中間介質量測環境介質中物質之活性………….....2-11 2.4 固相微量萃取(Solid Phase Microextraction, SPME) 應用於環境濃度測定之簡介………………........................2-13 2.4.1 中間介質作為活性量測之發展與應用………………….2-13 2.4.2 PDMS之物化特性………………………………..............2-14 2.4.3 SPME之吸收動力模式…………………………...............2-15 2.4.4 多氯聯苯之PDMS－水平衡分配常數之求得………….2-18 2.4.5 SPME之相關應用…………………………………...……2-19 2.5 SPME應用於研究之目的、困難及解決方向………………..2-20 第三章 研究方法…………………………………………………...3-1 3.1 研究架構………………………………………………………..3-1 3.1.1 多氯聯苯於二仁溪之暴露途徑…………………………...3-1 3.1.2 多氯聯苯於二仁溪各環境介質中之活性－總 量平衡模式建立…………………..…………….…………3-1 3.2 使用材料及其來源……………………………………..............3-3 3.3 計算光纖與各環境介質中多氯聯苯容量之比值…..................3-3 3.4 多氯聯苯以固相萃取時在各環境介質中之吸收 動力模式……………………………………………………….3-8 3.4.1 系統內含玻璃、凝相（魚體、底泥或水樣 相）、氣相、PDMS…………………………….…………3-8 3.4.2 標準品水溶液及水樣之吸收動力模式……….................3-10 3.4.3 底泥之吸收動力模式…………………………………….3-11 3.4.4 魚體之吸收動力模式…………………………………….3-11 3.5 環境介質中多氯聯苯吸收於PDMS之動力研究……………3-12 3.5.1 水中多氯聯苯吸收於PDMS動力研究方法…………….3-12 3.5.2 底泥中多氯聯苯吸收於PDMS動力研究方法.................3-12 3.5.3 魚體中多氯聯苯吸收於PDMS動力研究方法.................3-12 3.6 多氯聯苯Kpw之決定………………………………………….3-13 3.6.1 更新水溶液實驗………………………………………….3-13 3.6.2 不更新水溶液實驗……………………………………….3-14 3.6.3 決定Kpw及Kgw…………………………………………...3-15 3.6.4 實驗裝置………………………………………………….3-16 3.7 各環境介質中多氯聯苯活性之決定………………................3-16 3.8 各環境介質中多氯聯苯總量之決定………………................3-17 3.9 採樣方法………………………………………………………3-17 3.10 人體健康風險評估…………………………………..............3-18 3.11 分析方法……………………………………………………..3-20 3.11.1 標準品溶液來源及配製………………………………...3-20 3.11.2 使用儀器………………………………………………...3-21 3.11.3 氣相層析儀之操作條件………………………………...3-22 3.11.4 定性及定量分析………………………………………...3-22 第四章 結果與討論………………………………………………..4-1 4.1 實驗方法之討論………………………………………………..4-1 4.1.1 氣相層析儀穩定性測試…………………………...............4-1 4.1.2 實驗材料重複性分析……………………………...............4-2 4.1.3 氣相層析儀注入口降溫與不降溫比較…………………...4-3 4.1.4 氣相層析儀不分流時間之決定…………………………...4-4 4.2 各環境介質中多氯聯苯吸收於PDMS之動力 研究結果……………………………………………………….4-5 4.2.1 水相…...................................................................................4-5 4.2.2 底泥相……………………………………………………...4-5 4.2.3 魚體.......................................................................................4-5 4.3 Kpw之確定………………………………………………………4-9 4.4 各環境介質中多氯聯苯活性之比較………………................4-12 4.4.1水樣活性空間上之分佈…………………………………..4-12 4.4.2底泥活性空間上之分佈…………………………………..4-16 4.4.3 魚之平均活性…………………………………………….4-21 4.4.4 水、底泥、魚體之活性綜合比較……………………….4-28 4.4.5 多氯聯苯於二仁溪暴露途徑之討論……………………….4-33 4.5 有機質及脂質對水之平衡分配常數………………................4-34 4.5.1 有機質－水平衡分配常數…….…………………………4-34 4.5.2 脂質－水平衡分配常數….……...…………….................4-37 4.6 本研究各平衡分配常數與文獻之比較……………................4-41 4.6.1 Kpw…………………………………………………............4-41 4.6.2 Kom…………………………………………………............4-44 4.6.3 BCFL……………………………………………….............4-47 4.7 人體環境風險評估及底泥清除目標建議……………………4-50 第五章 結論與建議……………………………………..…………5-1 5.1 結論…………………………………………………….……….5-1 5.2 建議…………………………………………………..…………5-3 參考文獻............................................................................6-1 附錄A 公式推導……………………………………………….…附-1 附錄B 多氯聯苯於Aroclor中之質量百分比….…………..附-5 附錄C 實驗數據………………………………………………..附-1