() 3-Dimensional Risk Assesment of Perchlorate Contamination in Channel Catfish Using Three Different Simulated Dosing Regimens.
Albers, Eric1, Dixon, Kenneth, 1 The Institute of Environmental and Human Health - Texas Tech University, Lubbock, TX, USA
ABSTRACT- Site-specific risk assessments commonly result in large amounts of information that needs to be processed for a wide, often non-scientific, audience consisting of risk managers, regulators, and other decision makers. For this work we combined a series of models into a large virtual representation of the study system. By combining environmental transport models with an animal movement model and a physiologically based toxicokinetics (PBTK) model that has an embedded effects model, it is possible to arrive at a more accurate determination of risk compared to just a maximum-dose approach. A hypothetical lake system was created to study the impacts of perchlorate (ClO4-) on thyroid hormone secretion in the channel catfish (Ictalurus punctatus). Two scenarios were modeled accounting for groundwater upwelling into the lake and effluent discharge near the surface. Results were compared between environmental systems and the three dosing techniques; maximum dose, time-lapsed maximum dose, and location specific dose. Perchlorate tissue concentrations for liver, kidney, fat, skin, muscle, GI tract, and thyroid, as well as hormone levels and secretion rates were simulated. Through the use of commercially available graphics software MAYA©, we were able to generate 3-dimensional visualizations of our PBTK model, thyroid hormone secretion, and catfish movement, further aiding in data comprehension. This study shows the use of technological and computational advancements to generate more realistic and understandable risk assessment scenarios.
Key words: modeling, PBTK, visualization, perchlorate