EVALUATION OF BIOACCUMULATION FACTORS IN REGULATING METALS

Regulating metals on the basis of simple measures of bioaccumulation i n aquatic organisms gives misleading results. Simple bioaccumulation f actors are useful in characterizing the hazard posed by hydrophobic or ganic compounds, but the bioaccumulation of metals is more complex. Fo r metals that are essential for health, many organisms have the abilit y to control and maintain internal metal concentrations in the presenc e of significant variations in external concentrations. Hence bioaccum ulation factors expressed as the ratio of wet tissue concentration and water concentration must vary according to external concentration. Re gulations that specify a single generic accumulation factor are thus i nappropriate.