Part 3 Accumulation and elimination of organochlorines after exposure to sublethal concentrations in seabass Organ-specific accumulation and elimination patterns of PCBs in adult seabass (Dicentrarchus labrax)

The present study quantifies and explains the differences between measured organ-specific polychlorinated biphenyls (PCBs) accumulation and elimination kinetics in seabass (Dicentrarchus labrax) comparing these results with calculations using the generic model OMEGA. Specimens of approximately 250 g were selected and fed with food contaminated with PCBs 18, 44, 49, 52, 101, 105, 118, 138, 180 and 187. The OMEGA model was applied using a measured biomass (re)production coefficient and the food ingestion coefficient. It produced estimations of total body concentrations within a factor between 1.5 and 7.0 times of the measured and it also reproduced the general trend of the PCB concentrations during the experiment. This study allows us to confirm that there is a significant effect of internal distribution of PCBs in the tissues elimination rate constants and consequently in tissues bioaccumulation factors (BAF). The distribution of PCBs within the organism was slower than reported before, due to the bigger body size and the high lipid content of these fish. The present study indicates that internal organs (liver and visceral fat) can act as a contaminant sink, producing a variation pattern in muscle that differs from the overall body. This factor is enhanced if the organism has high lipid content.