Test of a Model for Predicting the Body Burden of Trace Contaminants in Aquatic Consumers

Abstract

A model for predicting the accumulation and retention of trace contaminants obtained through food ingestion in aquatic consumers was tested for short-term exposure conditions. Model parameters were determined in a single-feeding experiment using bluegill (Lepomis macrochirus) and food labeled with ¹³⁷Cs. Independent of this single-feeding experiment, bluegill were allowed to ingest ¹³⁷Cs contaminated food over a 16-day period and the predicted and measured body burden of the radionuclide were compared. The model realistically simulated the absorption of ¹³⁷Cs from the gastrointestinal tract and its accumulation over the 16-day period. Average body burden of ¹³⁷Cs in bluegill was within 25% of the predicted body burden when the experiment was terminated. Apparent equilibrium of ¹³⁷Cs in bluegill by day 16 suggests that this two-compartment linear model does not apply to the long-term accumulation of cesium in fish. The model appears most applicable for predicting body burdens of trace contaminants under acute exposure conditions that simulate an accidental release.