Anthropogenic activities including industrialization, urbanization, and agriculture have resulted in frequent detection of contaminants of emerging concern (CECs) across Great Lakes tributaries. Thus, there is a need to identify CECs of high and low ecotoxicological concern to help focus risk assessment and regulatory efforts. Here we present a weight-of-evidence framework developed to prioritize organic contaminants detected within the Milwaukee Estuary Area of Concern (AOC) (Milwaukee, WI). Chemical prioritization was carried out using experimental data (in vivo, in vitro, and analytical data) generated in 2017 -2018 Milwaukee AOC caged-fish studies, and chemical-specific data collated from US EPA databases (CompTox Chemicals Dashboard, ECOTOXicology Knowledgebase, ToxCast database) and/or estimated using quantitative structure-activity relationships. Overall prioritization was based on multiple lines of evidence: Detection Characteristics (spatial frequency, temporal frequency, environmental distribution), Environmental Fate (persistence, bioaccumulation, biomagnification), Ecotoxicological Potential (exceedence of water quality, in vivo, and in vitro toxicity benchmarks), and Effect Covariance (covariance with effects in caged fish studies). Results indicated within the Milwaukee Estuary AOC, 19/83 CECs were high priority, 13/83 were low priority, and 19/83 were data limited, requiring further investigation for prioritization efforts. Overall, this study presents an effect-based weight-of-evidence strategy that can be employed for CEC prioritization, and highlights several chemicals of ecotoxicological interest within the Milwaukee Estuary AOC.

This dataset is associated with the following publication: Maloney, E., D. Villeneuve, B. Blackwell, K. Vitense, S. Corsi, M. Pronschinske, K. Jensen, and G. Ankley. A framework for prioritizing contaminants in retrospective ecological assessments: Application in the Milwaukee Estuary (Milwaukee, WI). Integrated Environmental Assessment and Management. Allen Press, Inc., Lawrence, KS, USA, 19(5): 1276-96, (2023).