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年度	106	專案性質	非實驗性質
專案類別	研究專案	研究主題	整治
申請機構	國立高雄海洋科技大學	申請系所	海洋環境工程系
專案主持人	林啟燦	職等/職稱	教授
專案中文名稱	受戴奧辛及汞污染底泥之生態風險評估-以安順場址為例
中文關鍵字	戴奧辛,汞,底泥,生態風險評估,安順場址
專案英文名稱	Ecological Risk Assessment for the Dioxins and Mercury Contaminated Sediment at the An-Shun Remediation Site
英文關鍵字	Dioxins,Mercury,Sediment,Ecological Risk Assessment,An-Shun Remediation Site
執行金額	1,000,000元
執行期間	2017/1/9 至 2017/11/30
計畫中文摘要	戴奧辛及汞係難分解且高毒性之持久性有機污染物，對於生態環境與人體健康危害甚鉅。本計畫針對台灣台南前台鹼安順廠已關廠之鹼氯與五氯酚工廠，擇其海水貯水池中的底泥進行生態風險評估，及建置概念性場址模型，使風險評估者或其他利害關係人能夠更深入瞭解本案場。 本計畫之風險評估系統，係篩選自美國、加拿大、英國與澳洲等各國針對其污染場址所訂定之生態風險評估指引，賴以建立本計畫使用之生態風險評估架構。首先，先進行安順污染場址的資料蒐集與補充調查，再將資料彙整歸類，以建置安順場址之概念性場址模型及污染傳輸路徑圖。 本計畫團隊目前蒐集資料，包含：SCI國際期刊論文、美國環保署(USEPA)、英國環境署(Environment Agency)、加拿大環境部長理事會(Canadian Council of Ministers of the Environment)、澳洲環保議會(National Environment Protection Council)、Contaminated Site Clean-Up Information (CLU-IN)、美國材料與試驗協會(American Society for Testing and Materials, ASTM)、我國環保署專案計畫，以及國內論文期刊等資料庫之文章、技術報告、指引等共325篇文獻，經歸納後決定專注於USEPA、ASTM及重點國際期刊論文等相關指引；尤其是美國環保署(1998)「Guidelines for Ecological Risk Assessment」及特別針對超級基金場址提出一套評估指引「Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments」。 本團隊已針對底泥污染與評估終點進行本場址初步生態風險評估的計算(以民國99年調查計畫報告之底泥及魚蝦蟹數據為基準)，且進行定性定量之探討，評估項目包含：污染程度校正值(modified degree of contamination, mCd)、污染指數(pollution index, PI)、地質累積指數(geoaccumulation index, I-geo)、潛在生態風險指數(potential ecological risk index, RI)、風險商數(risk quotient, RQ)以及生物濃縮因子(bioconcentration factor, BCF)等等。 評估結果顯示，由污染程度校正值(mCd)、污染指數(PI)可知，在算術平均值之結果分別為40.44及56.01，均屬於最高等級的污染程度。然而，在幾何平均值的計算下，mCd為8.10，屬於分類等級4的污染程度，但PI為11.23仍大於PI指標之上限值。因此，整體而言，海水貯水池的底泥污染仍是屬於最高等級之污染程度。另一用於評估底泥中重金屬(汞)污染之地質累積指數(I-geo)計算之結果顯示，在算術平均值計算下，I-geo值為5.50屬於最高等級6的極度污染；而在幾何平均值計算下，其結果為3.19屬於等級4的嚴重污染；因此可知，底泥中汞之污染仍屬高污染。再者，由潛在生態風險指數(RI)與風險商數(RQ)初步計算之結果，在算術平均下，戴奧辛及汞之RI分別為958.25和2724.18，均屬於最高等級的非常高風險；而在幾何平均下，汞之RI為546.42係屬於300至600之間的較高風險，戴奧辛之RI則較低為190.67係介於150至300之間的中度風險(moderate risk)。對於RQ而言，分別在算術平均與幾何平均值下之結果為，汞分別為1481.27和297.12，而戴奧辛分別為1025.14和203.98；其不論是算術平均或幾何平均之戴奧辛及汞，計算出來的RQ均是大於1；因此，顯示海水貯水池之底泥中戴奧辛及汞，對於水生生態環境所造成的風險很高。 而生存在海水貯水池中的水生生物種類其生物濃縮因子(BCF)顯示戴奧辛具有非常高之生物濃縮潛勢；整體魚蟹中戴奧辛之BCF值(2.70E+3至1.09E+5)較汞的BCF值(25.33至189.67)高出數百倍，且戴奧辛的BCF均超過指標之最高上限值5000，表示對於生物種而言戴奧辛為非常生物累積；而汞在生物體中積累的潛勢相對較低，因此，相較於戴奧辛，汞則屬於較低之生物濃縮潛勢；而水生魚蟹中則以海鰱體內的戴奧辛及汞之BCF最高；其次為紅帶海鯡鯉、大鱗梭與鋸齒青蟳等。綜合而言，安順場址內海水貯水池之底泥，其各別受戴奧辛及汞污染程度與潛在風險都屬於最高等級。 本計畫由前述5個底泥風險評估計算因子推估案場海水貯水池之底泥整治目標，結果顯示，底泥可接受之戴奧辛濃度介於0.85至136.40 ng-TEQ/kg之間；而底泥中可接受之汞濃度則介於0.02至3.26 mg/kg之間；前述5項底泥風險評估指標中，又以RQ及PI兩指標影響最巨。對於水生生物體可被接受之風險而言，僅有BCF一項指標可為參考；依據BCF反推所得到之生物體可接受之戴奧辛濃度為2 ng-TEQ/kg，而生物體中可接受之汞濃度則為30 mg/kg。 綜合結果顯示，分布於工廠排水口處及往鹿耳門溪出海處這兩處之底泥，具有高濃度之戴奧辛及汞污染，因此，可優先對此區域加密調查且進行工程控制或整治技術評估；對於海水池中水生生物而言，雖然其體內汞濃度均在標準之內，但是其體內戴奧辛濃度仍具相當風險，因此建議該採取行政禁制或工程方面之防治行動，以控制污染的擴散及避免再次危害至人體與環境。綜合而言，本計畫提供相關風險管理及整治技術建議，可採行風險基準矯正行動，包含行政禁制、工程控制及整治技術等等。其中，行政禁制方案包含：場址周邊設置圍籬，並架設監視系統監控，禁止捕獵並張貼公告，撲殺焚化受污染魚蟹等等；工程控制方案包含：設置圍堤避免陸域污染土壤進入水域，且關斷海水閘門，進行底泥濬泥作業，並設置廢水淨水廠，處理抽出污染底泥之廢水等等。整治技術方案可採行美國環境保護署提出之底泥整治建議，其技術包含：不採取行動、現地整治、監測式自然復育、現地封蓋及疏濬或挖掘等等整治技術方案；此外，亦可以擷取各整治技術之優勢並相互補足其缺失，使用複合式整治技術進行整治，以有效提高去除率且降低各區域之潛在風險及整治成本。 後續，若進一步深入執行本場址海水池底泥整治目標之評估，建議應進行更準確的生態風險估算及健康風險評估，且持續評估戴奧辛及汞在水和底泥中的形態及傳輸機制，使海水池的風險評估更具代表性。以風險結果推算其合適之整治目標，再對於技術可行性及經濟可行性進行細部評估，以訂定更詳細之風險管理規劃及對策，且執行最佳風險基準矯治行動，以達到整治目標及早日解除場址管制之總體效益。
計畫英文摘要	On July 20, 2011, Taiwan-EPA posted The Technical Guideline of Health Risk Assessment for the Environmental Protection in Taiwan. However, the Health Risk Assessment Guideline fell short of providing the Ecological Risk Assessment methodology. In order to enhance our health risk assessment protocol, the Project Team had researched the ecological risk assessment tools and methodologies from countries that had advanced experience in ecological risk assessments, including United States, Canada, England and Australia. The Project Team integrated the selected tools and methodologies into a tool and methodology that are more suitable for us in Taiwan. The integrated tool and methodology were tested through assessing the ecological risk at the An-Shun Site to establish the CSM and the frame work for our ecological risk assessment in Taiwan. Based on the results from refinement processes of the tool and methodology, the Project Team has reached the project goals for developing our own ecological risk assessment tool and protocol. The ecological risk assessment results will also be used for risk communication before the risk based site remedial actions can be proposed. Guidelines for site ecological risk assessment from the United States, England, Canada, and Australia were the basis for developing the risk assessment system for this project. The risk assessment system provided the frame work for future ecological risk assessment. In order to refine the ecological risk assessment system, the Project Team started with collecting site information from the An-Shun facility and conducting additional site investigation to fill the information gaps. All the relevant information and site previous and current conditions were organized and built into a database with different categories in supporting the ecological risk assessment. Upon the completion of data and information collection, the Project Team established the physical model of the An-Shun site. The transfer paths of chemical of concerns (COCs) and potential risk exposure routes were identified for the ecological risk assessment at the site. In addition to the guidelines for ecological risk assessment from varies countries, the Project Team had collected and reviewed over 325 relevant documents including: • SCI journal articles, • Technical reports from USEPA, Environment Agency of England, Canadian Council of Ministers of the Environment, National Environment Protection Council of Australia, Contaminated Site Clean-Up Information (CLU-IN), and American Society for Testing and Materials (ASTM), • Taiwan EPA’s research project reports, • Journal articles published in Taiwan, and • Technical reports, dissertations and research abstracts. After completing the literature review phase of the project, the Project Team would propose to focus on the methodologies provided by USEPA and ASTM especially from the “Guidelines for Ecological Risk Assessment, 1998” and “Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessments.” Regarding the risk assessment of the key COCs at the An-Shun site, literatures for Mercury were relatively more than the literatures for Dioxins. With limited ecological risk assessment for Dioxins, the Project Team focused on the knowledge provided by professor Antonio Marcomin of the University Ca' Foscari of Venice in Italy. Future research topics and suggestions to overcome the limitation in the area Dioxins’ risk assessment are aslo suggested in this final project report. As of today, the Project Team has completed the estimations of the risk posted by the COCs in sediments of the An-Shun site according to the above mentioned sediments and bio-tissues collected in 2000. These calculation include: • Modified degree of contamination, mCd, • Pollution index, PI, • Geoaccumulation index, I-geo, • Potential ecological risk index, RI, • Risk quotient, RQ, and • Bioconcentration factor, BCF. The preliminary results from mCd, PI, and I-geo indicated that the elevated Dioxins and Mercury concentrations in sediment of the An-Shun site posted high risk for biological receivers. The preliminary results for RI and RQ also showed the high risk of the ecological system at the site from the Dioxins and Mercury in the sediments of both saltwater basins. Based on the calculations of BCF for both Dioxins and Mercury, it appeared that Dioxins had very high potential of bioaccumulation than the Mercury. Among the all bio-receivers, the Elops machnata had the highest BCF. Detailed discussion of all the qualitative and quantitative assessment are presented in the main text of this report. In summary, the Dioxins and Mercury in sediments in sea water basins of the An-Shun site posted very high risk for bio-receivers and the ecological system. The combined impact of the Dioxins and Mercury has not yet been assessed. More updated assessments as required by the Tier II and or Tier III (if necessary) are warranted, and should base on the most updated sediments and bio-tissues data. Finally, the Project Team has provided suggestions and recommendations for the site correction measures.