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An integrated approach for identifying priority contaminant in the Great Lakes Basin -Investigations in the Lower Green Bay/Fox River and Milwaukee Estuary areas of concern
Citation:
Li, S., Dan Villeneuve, J. Berninger, B. Blackwell, J. Cavallin, M. Hughes, K. Jensen, Z. Jorgenson, M. Kahl, A. Schroeder, K. Stevens, L. Thomas, M. Weberg, AND G. Ankley. An integrated approach for identifying priority contaminant in the Great Lakes Basin -Investigations in the Lower Green Bay/Fox River and Milwaukee Estuary areas of concern. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, Netherlands, 579:825-837, (2017).
Impact/Purpose:
Growing numbers of numbers of contaminants are being detected in surface waters and other environmental media. For many of these contaminants, extensive hazard characterization and associated water quality guidelines or criteria are lacking, making it difficult to for managers to understand the potential hazards associated with site-specific exposures to complex mixtures. This has created a need to use efficient approaches to screen sites for potential contaminant-related hazards and define priorities on which to focus follow up monitoring, management, or risk assessment activities, as appropriate. This paper presents a case study in which a combination of effects-based monitoring and bio-effects prediction tools were employed to identify potential pathway-based bioactivities associated (or not) with chemicals detected at eight sites in two Great Lakes Areas of Concern. Pathway identification was used to identify specific sites and biological activities that may warrant follow-up investigation at certain sites. Coupled with existing AOP knowledge or targeted AOP development, these approaches can provide insights into potential ecological hazards that one might associate with chemicals at a site. Significant novel aspects of the study include alignment of integrated water sampling devices with in situ exposures of caged fish to provide closely coupled exposure and effects characterization data. Additionally, the study employs a novel application of US EPA’s ToxCast data to prioritize chemicals and bioactivities on the basis of which chemicals are present at concentrations at or near those that can elicit activity in high throughput screening assays. This manuscript demonstrates on-going development of practical methods that environmental managers in the states and regions can use to aid prioritization and decision-making regarding the potential significance and effects of contaminants in aquatic systems and potentially other media. These case studies directly support the Great Lakes Restoration Initiative, Action Plan II focus area on Toxic Substances and Areas of Concern. The approaches and tools have broader application as a demonstration of the application of the AOP framework and AOP-based tools in the context of environmental assessment and monitoring (CSS Project 17.01, Task 2.2).
Description:
Environmental assessment of complex mixtures typically requires integration of chemical and biological measurements. This study demonstrates the use of a combination of instrumental chemical analyses, effects-based monitoring, and bio-effects prediction approaches to help identify potential hazards and priority contaminants in two Great Lakes Areas of Concern (AOCs), the Lower Green Bay/Fox River located near Green Bay, WI, USA and the Milwaukee River Estuary, located near Milwaukee, WI, USA. Fathead minnows were caged at four sites within each AOC (eight sites total). Following 4 d of in situ exposure, tissues and biofluids were sampled and used for targeted biological effects analyses. Additionally, 4 d composite water samples were collected concurrently at each caged fish site and analyzed for 134 analytes as well as evaluated for total estrogenic and androgenic activity using cell-based bioassays. Of the analytes examined, 75 were detected in composite samples from at least one site. Based on multiple analyses, one site in the East River and another site near a paper mill discharge from lower Green Bay/Fox River AOC, were prioritized due to their estrogenic and androgenic acitvity, respectively. The water samples from other sites generally did not exhibit significant estrogenic or androgenic activity, nor was there evidence for endocrine disruption in the fish exposed at these sites as indicated the the lack of alterations in ex vivo steroid production, circulating steroid concentrations, or vitellogenin mRNA expression in males. Induction of hepatic cyp1a mRNA expression was detected at several sites suggesting the presence of chemicals that activate the Ah receptor. To expand the scope beyond targeted investigation of endpoints selected a priori, several bio-effects prediction approaches were employed to identify other potentially disturbed biological pathways and related chemcial constituents that may warrant future monitoring at these sites. For example, several chemicals such as diethylphthalate and naphthalene , and genes and related pathways, such as cholinergic receptor muscarinic 3 (CHRM3), estrogen receptor alpha1 (esr1), chemokine ligand 10 protein (CXCL10), tumor protein p53 (p53), and monoamine oxidase B (Maob), were identified as candidates for future assessments at the AOCs.. Overall, this study demonstrates that a better prioritization of contaminants and associated hazards can be achieved through integrated evaluation of multiple lines of evidence. Such prioritization can guide more comprehensive follow-up risk assessment efforts.
