Relationships between partition coefficient, uptake rate constant, clearance rate constant and time to equilibrium for bioaccumulation

Abstract

Theoretical derivations together with published experimental data on bioaccumulation of lipophilic compounds by certain groups of fish indicates that the uptake and clearance rate constants have a fixed relationship to the octanol to water partition coefficient over the partition coefficient range 10 2.5 to 10 6. This allows the calculation of times to establish effective equilibrium, and significant bioaccumulation of compounds in relation to the partition coefficient. By extrapolation superlipophilic compounds (partition coefficients > 10 6) have been shown to require a minimum period of 0.5 years increasing to 10 years when P = 10 8 to establish effective equilibrium and compounds with partition coefficients >10 13 are not bioaccumulated to any significant extent. In practice then, a direct relationship between the bioaccumulation factor and the partition coefficient will not result with superlipophilic componds.