Sediment Extraction Using Deposit-Feeder Gut Fluids: A Potential Rapid Tool for Assessing Bioaccumulation Potential of Sediment-Associated Contaminants

Environmental Laboratory Approved for public release; distribution is unlimited. The contents of this report are not to be used for advertising, publication , or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. The findings of this report are not to be construed as an official Department of the Army position, unless so designated by other authorized documents. ISSUE: Traditionally, measuring contaminant bioavailability from dredged material has involved a 28-day bioaccumulation test. This phase is often the most expensive component of dredged material testing, due to the time taken and the trained analytical technique required. Current testing guidelines include a screening tool, the theoretical bioaccumulation potential (TBP), to minimize the need to resort to such bioaccumulation tests. However, TBP is limited to nonpolar organic compounds. Experimental screening tools, such as sediment extraction using deposit-feeder gut fluids, might offer a reliable screening tool for assessing concentrations of both polar and nonpolar compounds potentially available for bioaccumulation. RESEARCH OBJECTIVE: The objective of this project was to assess the efficacy and suit-ability of sediment extractions using natural and synthetic invertebrate gut fluid as a measurement of contaminant bioavailability and bioac-cumulation. SUMMARY: Recent studies have shown that contaminants released from sediment following in vitro incubation with deposit-feeder digestive fluid can provide a reliable measurement of bioavailability, and might be a good predictor of bioaccumulation. It is therefore conceivable that chemical analysis of gut-fluid extracts might be a rapid and cost-effective tool for screening potential bioaccumulation hazards associated with dredged sediments. This report outlines work to date on this technique, as well as current research goals. These goals include correlation analysis of bioaccumulation with gut-fluid extraction for a number of analytes, organisms, and sediments; development of a biomimetic (synthetic) gut fluid; examination of the importance of redox chemistry and digestive ligands in metal bioaccumulation; and the effects of contaminant and sediment matrix interactions on bioaccumulation. Please reproduce this page locally, as needed.