Emerging Water Contaminants: Investigating and Mitigating Exposures and Health Risks - OVERALL SUMMARY/ABSTRACT The Yale Superfund Research and Training Program (YSRTP) is driven by regulatory and community-based concerns about emerging contaminants that affect water resources and drinking water supplies at multiple sites in the US. The YSRTP has chosen to study 1,4-dioxane (1,4-DX) because of its common occurrence in Superfund sites and drinking water supplies, and its USEPA and IARC classification as a possible human carcinogen. The carcinogenic mechanism in the liver is unknown and its interaction with co-occurring and carcinogenic water contaminants (1,1,1-trichloroethane, 1,1,1-trichloroethylene, and 1,1-dichloroethane) has never been evaluated in either animals or humans. Given that liver cancer incidence rates have more than tripled since 1980, there is an urgent need to evaluate whether emerging water contaminants, such as 1,4-DX, may be contributing to this increase. Importantly, a lack of biomarkers of exposure to or the biological effects of 1,4 -DX have hampered epidemiologic studies, risk assessment and setting standards for the contaminant. In addition, the high polarity and low biodegradability of 1,4-DX restrict the ability to remove it from aquifer systems or drinking water. Indeed, available treatment technology is both expensive and not readily applied to water supplies. The YSRTP will foster problem-based, solution-oriented research related to 1,4-DX and its co-occurring contaminants through innovative approaches to evaluate environmental occurrence and human exposure, understand the underlying basis of adverse health effects, provide cost-effective remedial mitigation solutions and ultimately set the stage for improved regulation of this emerging contaminant. The YSRTP will carry out highly interactive projects to: (a) examine the health effects and biomarkers of exposure/effect to 1,4-DX (alone and as a mixture with its co-occurring contaminants) in animal models and humans, and (b) develop systems to monitor and mitigate human exposure to 1,4-DX in water. The biomedical science research projects will elucidate the mechanism(s) associated with 1,4-DX liver toxicity and carcinogenesis in mouse and zebrafish models (project 1), and exposure assessment and early biologic responses to 1,4-DX in human populations (project 2). The environmental science and engineering research projects will create highly-sensitive and selective electrochemical sensors for on-site, real-time detection of 1,4-DX (project 3) and develop innovative advanced oxidation processes for mitigation technology (project 4). Successful completion of these innovative studies will make a significant positive health impact by more clearly defining the health risks of 1,4-DX, elucidating biomarkers of exposure, and establishing effective new ways to monitor and mitigate this important emerging contaminant. Our systems approach integrates and links the research projects with the development of effective communication and education of stakeholders, and training of future scientists to ensure the program has a far- reaching impact on how emerging contaminants are addressed both in the US and globally.
