Factors Determining Partitioning of Hydrophobic Organic Chemicals in Aquatic Organisms

Abstract

Correlations between the bioaccumulation tendency of organic chemicals in aquatic organisms and 1-octanol/water partition coefficients show a loss of linearity for very hydrophobic compounds. In order to establish the possible cause(s) of this phenomenon, the roles of metabolism, exposure time, membrane permeation, lipid solubility, and bioavailability on the biocon- centration potential of chemicals, are discussed. Data are presented showing their relative importance. It is concluded that, although insufficient experimental data presently exist which can conclusively establish the cause(s), reduced lipid solubility and reduced bioavailability are the most likely factors contributing to the loss of linear correlation for non-metabolizing chemicals.