Polychlorinated Biphenyl Transport in Coastal Marine Foodwebs

摘要

The extent to which polychlorinated biphenyls (PCBs) may be assimilated into fish from dietary sources was studied by providing known doses of PCBs (as Aroclor 1254 in food) to striped bass and analyzing cross-gut transport, tissue distribution and elimination. Assimilation and elimination data from single and multiple doses for whole fish were used to calculate rate-constants for PCB accumulation (k(a)) and elimination (k(e)) according to one-compartment pharmacokinetic models. The data from analysis of individual tissues were used to calculate ka and ke for individual tissue compartments. The major conclusions from the study are that PCBs in food represent a major source of PCB to fish (up to 80% of total body burdens). The PCBs obtained from food cause a rapid approach to steady state, but are eliminated slowly with a half-time of about 120 hr. More than 85% of the PCB ingested with food is assimilated into the tissues. The long-term model showed that PCB burdens in striped bass exposed to food containing different concentrations of PCB will decline slowly when levels in food decline, but increase rapidly (90% plateau reached in 9 doses) when levels in food increase. Preliminary verification studies support the pharmacokinetic model for PCB accumulation in striped bass with food as the major source.