Absorption Efficiency and Biological Half-life of Individual Chlorobiphenyls in Carp (Cyprinus carpio) Orally Exposed to Kanechlor Products

Abstract

The absorption efficiency and biological half-life of individual chlorobiphenyls in Kanechlor products were determined in carp (Cyprinus carpio) after acute dietary exposure. The absorption efficiences of individual chlorobiphenyls ranged from 67 to 93% and decreased as the number of chlorine atoms substituted in biphenyls increased. The metabolized PCBs in carp were confined to lower chlorine substitutes, and they had more chlorine atoms substituted in ortho positions. The absorption efficiences of PCBs by carp were nearly the same as the rat data reported earlier. However, the biological half-lives of PCBs in carp were much longer than those of rats. These results suggest that the absorption mechanisms through digestive tract are not dependent on specific physiological differences in vertebrates but on the physicochemical properties of individual chlorobiphenyls. On the other hand, the elimination of PCBs seems to be strongly dependent on the metabolic capacity of the species. The absorption efficiency and biological half-life of individual chlorobiphenyls appear to provide useful information on the behavior and fate of PCBs in the ecosystems.