TA4 Metals in the Environment: Dietary Concerns in Aquatic Systems
Room 16A/B, Level 4
8:00 AM - 12:00 PM, Tuesday, 11 November 2003
Chair: Adams, Bill ,
Co-chair: Meyer, Joe ,
(200) Evaluating copper bioaccumulation in aquatic ecosystems: dietary exposure.
Adams, William1, Brix, Kevin2, DeForest, David3, 1 Rio Tinto, Murray, UT, USA2 EcoTox, Miami, FL, USA3 Parametrix, Inc., Kirkland, WA, USA
ABSTRACT- The use of dietary and tissue thresholds based on contaminant concentrations in organisms is being considered in conducting aquatic risk assessments. For metals in general, and especially for essential metals like copper, this type of assessment cannot consist of simply estimating body burdens using accumulation factors (BCF, BAF, BSAF) and then comparing these estimated concentrations to a residue-based effects threshold. Exclusive of bioavailability considerations, a number of other factors such as uptake kinetics, essentiality, active regulation and assimilation efficiency must be considered when evaluating copper accumulation. Further, once copper is accumulated, an understanding of how it is transported and stored throughout the organism is critical to making reliable predictions of potential effects from excess copper. Many of these issues have been studied in an independent manner. We review the available bioaccumulation data for aquatic species (benthic and water column species), synthesize our understanding of key issues and develop a cohesive framework and model for assessing risks from copper bioaccumulation in aquatic systems including aquatic-linked terrestrial wildlife.
Key words: bioaccumulation, copper, BCF, BAF, dietary exposure