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(70-09) Inverse Relationship Between Exposure Concentration and BCF/BAF/BSAF for Metals: Implications for Hazard and Risk Assessment. Brix, Kevin*,1, DeForest, David2, Green, Andrew3, Adams, William4, 1 EcoTox, North Bend, Washington, United States2 Parametrix, Inc., Kirkland, Washington, United States3 ILZRO, Research Triangle Park, North Carolina, United States4 Kennecott Utah Copper Corp., Magna, Utah, United States ABSTRACT- In evaluating the potential hazard or risk posed by metals in the environment it is important to consider their bioaccumulative properties. Over the past several years bioconcentration factors (BCFs), bioaccumulation factors (BAFs), and biota-sediment accumulation factors (BSAFs) have either been proposed or actively used to assess metal hazard or risk in a variety of regulatory arenas. However, the inverse relationship between metal exposure concentration and corresponding BCF/BAF/BSAF is rarely considered or accounted for in these assessments despite this relationship having been demonstrated for a wide range of metals (Al, Ag, As, Cd, Cr, Cu, Fe, Pb, Ni, Se, Zn). In this paper, we will overview the substantial amount of laboratory and field data demonstrating this relationship, discuss the mechanistic basis for why such a relationship exists, and describe how existing assessment methodologies might be modified to properly account for it. Key words: metals, bioaccumulation, hazard assessment, risk assessment |
