Kinetics of polychlorinated biphenyl (PCB) components in juvenile sole ( Solea solea) in relation to concentrations in water and to lipid metabolism under conditions of starvation

Abstract

The kinetics of 19 PCB components in starving sole were related to PCBs in solution and to changes in lipid composition. Analyses were made of brain, liver, and ‘remainder’ of the fish. The pattern of PCBs in solution determined the pattern in fish. Lipid-based PCB concentrations in brain were 3–4 times lower than in liver and the remainder of the fish. No differences between the PCB patterns were observed. This allowed evaluation of PCB kinetics on the basis of total PCB concentrations (Σ-PCB as sum of the 19 components identified). The Σ-PCB concentrations on a lipid basis increased with starvation due to changing lipid contents and compositions of some organs and tissues or by an increase of PCB concentrations in solution with the pattern in solution remaining identical. Bioconcentration factors of PCB components were related to their K ow values. Despite the increase in concentrations, absolute amounts of PCBs in the remainder decreased with increasing starvation due to the decrease in lipid content of the tissues. In brain and liver the amounts per organ did not decrease. In field samples of organisms, PCB patterns remain essentially unchanged over a range of concentrations. This behaviour can be explained by the PCB kinetics observed in this laboratory study.