| Abstract: | The hazardous effect of a toxic compound is determined by its intrinsic toxicity and its environmental fate, governed by dynamic biogeochemical processes. A high persistence to microbial breakdown and biotransformation in higher organisms, combined with high lipophilicities1,2, leads to high bioaccumulation rates of PCB's, increasing the risk of chronic exposure. In laboratory studies with juvenile sole (Solea solea), bioaccumulation was influenced by differences between values of biological half-times of congeners, PCB patterns in food and water, differences between lipid contents of organs and changes in lipid speciation of some organs. In the field, highly similar PCB patterns are usually found within each of the compartments water, seston, sediment and within animal species. However, between them patterns differ.3–6 This is best explained by assuming that the patterns of congeners in organisms are ultimately determined by the pattern in solution and biological half-times of individual congeners; the latter can be influenced by differences in biotransformation capacity between species. |
