A physiologically based toxicokinetic model for fish was used to simulate the uptake and disposition of three waterborne chloroethanes in rainbow trout (Oncorhynchus mykiss). Trout were exposed to 1,1,2,2-tetrachloroethane, pentachloroethane, and hexachloroethane in fish respirometer-metabolism chambers to assess the kinetics of chemical accumulation in arterial blood and chemical extraction efficiency from inspired water. Chemical residues in tissues were measured at the end of each experiment. Trout exposed to tetrachloroethane were close to steady-state in 48 hr. Fish exposed to pentachloroethane were near steady-state in 264 hr. Extraction efficiency data showed that systemic (extrabranchial) elimination of both chemicals was small. Hexachloroethane continued to accumulate in fish exposed for 600 hr. Parameterized with chemical partitioning data obtained in vitro, the model accurately simulated the uptake of all three chloroethanes in blood and tissues and their extraction from inspired water. These results provide support for the basic model structure and the accuracy of physiological input parameters.
Bibliographical noteFunding Information:
This work was sponsored by the Air Force Office of Scientific Research, Air Force Systems Command, United States Air Force, under Grant Number, AFOSR-ISSA%P 0060. The U.S. Government’s right to retain a nonexclusive royalty-free license in and to the copyright covering this paper, for governmental purposes, is acknowledged. The authors thank Colleen Fredrickson and Carol Gallinat for their technical assistance, and Joe Tietge and Dr. Patricia Schmieder for reviewing the manuscript.