The aims of the present project were to (1) investigate distribution of concerned chemicals in fifteen rivers around Taiwan, (2) update the analysis data and link to specified database (3) simulate distribution patterns of certain chemicals in a specific river, and (4) update and establish the substance screening mechanism for investigation of environmental distribution of chemical substances and complete the priority order for the designated chemical substances. 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, Jiangjun River, Zengwun River, Gaoping River, Linbien River, Hualien River, Siouguluan River and Beinan River). Concentrations of dechlorane plus (DP), methoxychlor, perfluorinated alkyl substances (PFAS), pesticides and their metabolites (i.e., glyphosate, aminomethylphosphonic acid (AMPA), chlorpyrifos, pendimethalin) short-chain chlorinated paraffins (SCCPs), nonylphenol (NP), bisphenol A (BPA), phthalate esters (PAEs), polybrominated diphenyl ethers (PBDEs), hexabrominated biphenyls (HBB), polycyclic aromatic hydrocarbons (PAHs), and metals were measured in collected samples and 17,160 analyzed data were obtained. The analyzed concentrations of some chemicals in sediments showed decreasing trend. It indicates that the control strategies for these chemicals are effective to reduce their releasing into the environment. However, the concentrations of some chemicals (e.g., NP, BPA, PAEs, SCCPs, PBDEs and metals) in sediments and fishs were higher than those in the previous survey, the findings may be related with the living habit of fish or due to decreased polluted levels of river environment and then fish lived more time to conentrate those chemicals. We recommened it was necessary to continuously monitoring their distribution trend. In the future, candidate chemicals with global concerns, high production volume, environmental hazards and human health effects could be further included for long-term investigation.
Second, the analysis data and popular science information were updated to the "environmental distribution survey of chemical substances Information Website", and linked the environmental distribution survey data to the Central Data Exchange (CDX System) of the Environmental Protection Administration. The analysis data investigated by the relevant units of the Environmental Protection Administration were organized and linked to the ChemiCloud platform.
Third, assessments of the multiple media transport and health risk of cobalt and formaldehyde in the Tahan river basin were performed with simulated cobalt and formaldehyde levels in different environmental media. According to the results of health risk assessment based on groundwater pollution simulations in different scenarios, the main exposure routes were inhalation and dermal contact. The 95% UL of cancer risk was acceptableand 95% UL of non-cancer risk in each scenario were all below the threshold of health hazard effects. In the part of management decision model tool, the distribution and correlation of specific pollutants at specific time points and specific media can be observed through pivot analysis, Sankey diagram, and river survey fingerprints. Meanwhile, Toxicological Priority Index (ToxPi), the diverse toxicological information integration tool, was used for decision-making in chemical management.
Finally, the "Substance Screening Mechanism for Investigation of Environmental Distribution of Chemical Substances" was updated and established. A expert consultation meetings was held to discuss the screening mechanism. The priority selection of designated chemical substances was considered as the basis for future environmental distribution investigations of certain chemical substances.