ENBIS-18 in Nancy

2 – 25 September 2018; Ecoles des Mines, Nancy (France) Abstract submission: 20 December 2017 – 4 June 2018

Are the Ashtabula Fish Still Sick? – A Bayesian Bioequivalence Answer

5 September 2018, 10:00 – 10:30


Submitted by
Tim Robinson
Tim Robinson (University of Wyoming)
The Ashtabula River covers an area that lies in northeast Ohio, US, flowing into Lake Erie's central basin at the city of Ashtabula where its drainage covers an area of 355 km2. Native American inhabitants referred to the river as the Hash-tah-buh-lah or “river of many fish." Beginning in the early 1800s, the lower Ashtabula River was widened and deepened into a deep draft harbor to accommodate commercial shipping and shipbuilding enterprises. In the mid-1900s several chemical production companies began operation along tributaries of the Ashtabula and, over time, discharges from these facilities left the lower Ashtabula River heavily contaminated with polychlorinated biphenyls (PCBs), heavy metals and a suite of other agents. A tributary of the lower Ashtabula was named a Superfund site in 1983 and under the 1987 Great Lakes Water Quality Agreement, the lower 3.2 km of the Ashtabula River was designated as a Great Lakes Area of Concern (AOC). A variety of private and governmental agencies contributed to a cleanup of the lower Ashtabula and associated industrial sites from 1999-2013. To assess the efficacy of the clean-up efforts, several beneficial use impairments (BUI’s) were defined and by 2017, all but two of the BUI’s had achieved pre-defined remediated thresholds. One of the remaining BUI’s involves liver tumor rates and liver concentrations of PCB’s in Brown Bullhead catfish, a pre-identified indicator species. Statutes indicate that a BUI can be removed if it can be demonstrated that an impairment is not limited to the local geographic extent of the AOC, but rather is typical of area-wide conditions. In this talk, I describe a Bayesian approach to bioequivalence testing where the results are being used to support the removal of a BUI related to tumor rates and liver concentrations of PCB’s in the chosen indicator species.

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