This model predicts dynamic uptake, distribution, concentration, and toxicity for neutral organic chemicals for a fish containing four compartments: cell membrane, liver, richly perfused, and poorly perfused. Fish uptake is by respiration. The chemical is then distributed by the blood into a number of internal tissues (compartments) including cell or target membrane in which baseline toxicity (narcosis) occurs when a toxic endpoint is reached, the liver where loss by biotransformation occurs, richly perfused tissues that is fast-responding due to highly oxygenated tissues (e.g., brain, stomach, kidneys), poorly perfused tissues that is more slowly accessed by the blood and is more poorly oxygenated (e.g., muscle, fat, skin, bone). Required inputs are indicated by colour cells and data for two fish, a fathead minnow and trout, are present in a database along with references for the data. The model treats respiration, biotransformation (metabolism), and growth dilution processes. Results include steady-state fugacities and concentrations and several results as a function of time including fugacities and concentrations (compartment and whole-body), lipid-normalized concentration, concentration in membrane lipids, volume fraction percent in membrane lipids, chemical activity in membrane lipids, and probability of death.
This model contains a macro which must be enabled for the model to run.
Features of the Fish PBTK model:
- Estimates fish concentrations and probability of death due to uptake by respiration of a chemical in water
- Provides a small fish database
- Treats any neutral organic chemical
- Accounts for uptake and loss due to respiration, metabolic biotransformation, and growth dilution
- Spreadsheets can be edited
- Includes instructions sheet, guidance for choosing input values, and more in-depth information available in the publication
Based on the following publication:
- Celsie, A.K.D., Mackay, D., Parnis, J.M., Arnot, J.A. “A fugacity-based toxicokinetic model for narcotic organic chemicals in fish”. Environ. Toxicol. Chem. 35, No. 5, 1257-1267, 2016.
Required Input Data:
Chemical Properties
- Molar mass
- Vapour pressure
- Molar volume
- Henry’s law constant
- Log KOW
- Solubility
- KOW scaling factors to each compartment
Environmental Properties
- Water concentration
- Percent oxygen saturation
- Water temperature
Species Properties
Note: Species properties and source references are available in the model database
- Organism volume
- Growth rate constant, biotransformation rate constant
- Compartment volumes and lipid fractions
- Toxic endpoints
- Blood flow rate
Model output includes:
- Steady-state fish compartment and water fugacities and concentrations
- Time-dependent fish compartment and whole-body fugacities and concentrations
- Time-dependent probability of death values
- Graphs of time-dependent fish concentration (whole-body, lipid-normalized, membrane lipid), volume fraction percent in membrane, and chemical activity in membrane along with corresponding probability of death graphs
- Parameters summary page
Please read the software license before downloading the software. Use of the software constitutes your agreement to abide by the terms and conditions set out in the license agreement. Please report any problems to Prof. Mark Parnis.
Fish Physiologically Based ToxicoKinetic (PBTK) Model (Excel spreadsheet version 1.01, uploaded August 23, 2023)
July 2023 Copyright 2023 Trent University All Rights Reserved.
Coded by Alena Celsie