Evaluating copper bioaccumulation in aquatic risk assessments

摘要

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. In this paper we will review the available bioaccumulation data for several aquatic species, synthesize our understanding of key issues and develop a cohesive framework and model for assessing risks from copper bioaccumulation in aquatic systems.