Disposition of low and high environmental concentrations of PCBs in snapping turtle tissues.

Abstract

Snapping turtles, as a result of their ability to store high concentrations of PCBs in their fat, provide an excellent screen for the detection of trace toxic substances in water. Snapping turtles may also be of value in the monitoring of the disposition of environmental pollutants in the tissues of organisms living in a particular ecosystem. Many organochlorine compounds are only slowly metabolized by animals and consequently the parent compounds tend to persist in the tissues. Differences in the degree of dissolution of various polychlorinated hydrocarbons in blood may be attributed to differences in the relative solubility of these compounds in one or more of the blood components. It has been shown that binding of individual organochlorine compounds by lipoproteins and albumin involves slowly reversible hydrophobic interactions with a quasi steady state between adipose tissue, blood and remaining tissues. If such a dynamic equilibrium is involved, it might be anticipated that, under the impact of a multi-component pollutant such as an Aroclor, the biological system would respond in the same manner over a wide range of concentrations provided that the binding of each the congeners involved reversible interactions with the quasi steady state. The net result would be that themore » order of quantitative disposition of PCBs in the various tissues would be maintained as the concentration in each site increased. It is the objective of this study to determine if such a pharmacodynamic equilibrium is operative in snapping turtles subjected to widely differing degrees of PCB environment contamination.« less