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PHYSIOLOGICALLY-BASED TOXICOKINETIC MODELING OF THREE WATERBORNE CHLOROETHANES IN CHANNEL CATFISH, ICTALURUS PUNCTATUS
Citation:
Nichols, J., J. McKim, G. Lein, A. Hoffman, S. Bertelsen, AND C. Gallinat. PHYSIOLOGICALLY-BASED TOXICOKINETIC MODELING OF THREE WATERBORNE CHLOROETHANES IN CHANNEL CATFISH, ICTALURUS PUNCTATUS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-94/182 (NTIS PB94163615), 1993.
Description:
A physiologically-based toxicokinetic model for fish was used to describe the uptake and disposition of three chlorinated ethanes in channel catfish (Ictalurus punctatus). atfish were simultaneously exposed to 1,1,2,2-tetrachloroethane (TCE), pentachloroethane (PCE), and hexachloroethane (HCE) in fish respirometer-metabolism chambers to assess the kinetics of chemical accumulation in rterial blood and chemical extraction efficiency from inspired water. hemical residues in tissues were measured at the end of each experiment. hese data were used to evaluate the accuracy of model simulations and to form a basis for comparison with information collected previously from rainbow trout. CE was at or near steady-state in catfish after 48 h. or PCE and HCE the time to steady-state appeared to be considerably longer than 48h. Parametrized with in vitro chemical partitioning information, the model accurately simulated the accumulation of TCE in arterial blood and its uptake from inspired water, but consistently underestimated the uptake and accumulation of both PCE and HCE. he cause of these discrepancies was not conclusively determined however, several possible sources of error were evaluated, including physiological and chemical partitioning inputs, and underlying modeling assumptions. omparison of data sets and modeling efforts for rainbow trout and channel catfish suggests that gross similarities between the two species can be attributed to the comparability of relevant physiological and chemical partitioning parameters.