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.
Chemical Substances, Environmental distribution, River, Sediment, Fish, Multiple media transport, Management and guidance for release of chemical substances, Risk-screening environmental indicators