Kinetic models for predicting bioaccumulation of pollutants in ecosystems.

Steady state kinetic models, which may be useful for the prediction from simple data, of the bioaccumulation of liophilic pollutants in ecosystems are discussed. For some aquatic species, such as Mytilus edulis, bioconcentration factors (BCFs) are closely related to water solubilities, and octanol: water partition coefficients (Kows). In other cases, more complex models are necessary to take account of metabolism and/or uptake from food. Somewhat different considerations apply in the estimation of bioaccumulation factors (BFs) for terrestrial organisms that cannot excrete lipophilic compounds by diffusion into ambient water. The relationship between half-lives and BFs is discussed. Metabolism is necessary for the effective elimination of lipophilic pollutants by terrestrial animals, and a model is proposed for the prediction of BFs from kinetic data obtained from in vitro metabolism studies. If such a model can be successfully developed it will make possible the prediction of bioaccumulation of pollutants by a wide range of species which cannot be studied by present methods.