This abstract submitted to the session celebrating Dr. Danny Reible’s contributions will build on the legacy of his research and focus on emerging understanding of pollutant bioavailability in contaminated sediments.  <br/>The development of equilibrium passive sampling methods has accelerated over the last decade and enabled measurements of ultra-low concentrations of bioaccumulative chemicals in the aquatic environment.  Yet, use in the regulatory context has been limited due to the lack of precedent and solid demonstrations tied closely to regulatory needs. Remedial investigations of sites contaminated with legacy pollutants like polychlorinated biphenyls (PCBs) have traditionally focused on mapping sediment contamination to develop a site conceptual model and select remedy options. This sediment-focused approach often leads to an incomplete understanding of the impacts of ongoing inputs to the water column and over-estimation of potential effectiveness of sediment remediation. Here we demonstrate how measurements of surface water, sediment porewater, and gas-phase PCB concentrations using polyethylene passive samplers were able to provide the first accurate mass balance of freely dissolved PCBs in the Anacostia River in Washington DC. This mass balance enabled identification of a major tributary and contaminated sediment hot-spots as the sources having the most negative impact on the water body, while also demonstrating that the atmosphere served as a sink for PCBs from the surface water.  By coupling the mass balance model with a food web model for the river, we were able to connect the media concentrations to bioaccumulation in fish and evaluate a range of management options.  We demonstrate that sediment cleanup alone will not be able to achieve target reductions of PCBs in fish and dissolved concentrations from the problem tributary needs to be controlled.  The framework presented here for passive sampling and interpretation can be used to provide robust and sustainable solutions for other river systems.

Monitoring freely dissolved concentrations of hydrophobic pollutants improves understanding of pollutant transport and bioaccumulation with clarity on sustainable management options

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.