本計畫主要目的包括(1)優先調查化學物質於臺灣本島主要15條河川環境流布進行調查，並與歷年資料進行比對分析、(2)進行河川流域之特定範圍與特定化學物質項目，比對相關排放源並模擬研析流布途徑、與(3) 強化國內化學物質釋放量管理法令及配套措施研析。第一部分已完成淡水河本流、大漢溪、新店溪、基隆河、大甲溪、濁水溪、八掌溪、急水溪、將軍溪、曾文溪、高屏溪、林邊溪、花蓮溪、秀姑巒溪、卑南溪等15條河川之底泥及魚體採樣及分析，檢測項目包括，全氟辛烷磺酸及全氟辛酸、大克蟎、嘉磷塞及氨基甲基膦酸、短鏈氯化石蠟、壬基酚及雙酚A、鄰苯二甲酸酯類、多溴二苯醚類及六溴聯苯類、多環芳香烴化合物、金屬及甲基汞等9類95種檢測物質，獲得15,675筆檢測數據。環境流布調查結果發現化學物質含量較初期調查結果有降低趨勢，顯示列管後有助於降低河川環境中優先調查化學物質濃度。惟本年度調查結果發現部分檢測項目如雙酚A、鄰苯二甲酸二(2-乙基己基)酯及多溴二苯醚類之測值相較前一次調查結果有上升情形，建議應持續監測觀察其環境流布之趨勢，未來可繼續納入國際關注、國內使用量高、具環境及人體危害特性之化學物質進行長期調查。第二部分係分別以實地水體採樣及地下水擴散模擬進行南崁溪流域之多介質與健康風險評估。以地下水及雙灌溉水源進行多介質與健康風險評估，結果顯示「農作物及魚肉食入吸收」為人體主要暴露途徑。致癌風險評估結果，依情境不同，95th致癌風險分別為4.17E-8及4.30E-5，As為致癌風險之主要貢獻金屬；95th非致癌風險結果顯示依情境不同，95% UL HI為0.0014及1.71，主要貢獻金屬依模擬情境不同而有差異，情境一主要貢獻金屬為Cu，情境二主要貢獻金屬為Pb。第三部分為延續108年計畫成果精進釋放量計算及管理，完成釋放量管理法令修正建議、計算指引修正建議、相關配套措施規劃及產業影響評析，並提出中央與地方合作模式之可行作為，以強化毒化物之管理。提供毒化物運作業者正確釋放量計算及減量策略擬定之諮詢。完成以DEHP、DBP、DecaBDE及BPA為例之跨資料庫（釋放量、運作量及環境流布調查資料庫）評析，並完成設計並建置視覺化及主題化網站「毒化物申報暨流布資料加值應用平台」。另已初步建置「台灣風險篩選環境指標模式」，並應用於毒性化學物質政策導向之整合分析，提供以健康風險為基礎之毒化物管理政策參考依據。

The major aims of this project were to (1) investigate distribution of concerned chemicals in fifteen Taiwanese rivers, (2) simulate distribution patterns of particular chemicals in a specific river, and (3) propose national management strategies for toxic chemicals release. First, sediment and fish samples were collected from fifteen Taiwanese rivers (i.e., Danshuei River, Sindian River, Dahan River, Keelung River, Dajia River, Jhuoshuei River, Bajhang River, Jishuei River, Shincheng River, Zengwun River, Gaoping River, Linbien River, Hualien River, Siouguluan River and Beinan River). Concentrations of perfiuorooctane sulfonic acid (PFOS), perflurooctanoic acid (PFOA), dicofol, glyphosate and aminomethylphosphonic acid, short-chain chlorinated paraffins (SCCPs), nonylphenol (NP), bisphenol A (BPA), phthalate esters (PAEs), polybrominated diphenyl ethers (PBDEs), hexabrominated biphenyls (HBB), polycyclic aromatic hydrocarbons (PAHs), metal and methylmercury were determined in collected samples and 15,675 analyzed data were obtained. The concentrations of most analyzed chemicals in sediments shows temporal decreasing trend. The results indicate that the control strategies of the usage of those chemicals are effective to reduce those release into the environment. However, the survey results of this year found that the concentrations of some analyzed chemicals e.g. BPA, DEHP and PBDEs shows increasing trend compared with the previous survey results. It is recommended to monitor the environmental distribution trends of these chemicals continuously. It will be also included the candidate chemicals with global concerns, high production volume, environmental hazards and human health effects into the background investigation of environmental distribution of chemical substances. Second, assessments of the multiple media transport and health risk of metals in the Nankan river basin was performed using measured metal concentrations in water and simulated metal levels in different environmental media. As to the results of health risk assessment based on wastewater pollution simulations in different water irrigation scenarios, the main exposure route was the consumption of fish and crops. The cancer risk of 95% UL in scenarios I and II was 4.17E-8 and 4.30E-5, respectively, and As was the main contributor. The non-cancer risk of 95% UL HI in scenarios I and II was 0.0014 and 1.71, respectively, and Cu and Pb was the main contributor in scenario I and II. Finally, following the conclusions of 2019 project, the release managements of toxic chemicals were suggested: 1) tighten the reporting threshold in release of toxic chemicals; 2) revised version of guidelines for the Designation of Toxic Chemical Substances and Estimation of Releases, 3) complementary measures for release managements of toxic chemicals, 4) the cooperative managements between government and local agencies. The project provide the consultant for estimation and reduction of toxic chemical releases. Moreover, a cross-database (the releases reporting, operation scale and environmental fate of toxic chemicals) visualization website and Taiwan Risk-Screening Environmental Indicators (Taiwan RSEI) model were established for the policy-based integrated analysis on toxic chemicals. DEHP, DBP, DecaBDE and BPA were taken as the examples for the integrated analyses.