title: The chemical exposure toxicity space (CETS) model: Displaying exposure time, aqueous and organic concentration, activity, and onset of toxicity.
abstract: A 1-compartment toxicokinetic model is used to characterize the chemical exposure toxicity space (CETS), providing a novel graphic tool that can aid in the design of aquatic toxicity tests for fish and for interpreting their results. The graph depicts the solution to the differential equation describing the uptake kinetics of a chemical by a modeled fish under conventional bioassay conditions. The model relates the exposure concentration in the water to a dimensionless time and the onset of toxicity as determined by an estimated or assumed critical body residue or incipient lethal aqueous concentration. These concentration graphs are specific to each chemical and exposure and organism parameters and clearly demonstrate differences in toxicity between chemicals and how factors such as hydrophobicity influence the toxic endpoint. The CETS plots can also be used to assess bioconcentration test conditions to ensure that concentrations are well below toxic levels. Illustrative applications are presented using a recent set of high-quality toxicity data. Conversion of concentrations to chemical activities in the plots enables results for different baseline toxicants to be superimposed. For chemicals that have different modes of toxic action, the increased toxicity then becomes apparent. Implications for design and interpretation of aquatic toxicity tests are discussed. The model, and pictorial visualization of the time-course of aquatic toxicity tests, may contribute to improvements in test design, implementation, and interpretation, and to reduced animal usage. Environ Toxicol Chem 2017;36:1389-1396. © 2016 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.
authors: Chemical Properties Research Group, Department of Chemistry, Trent University, Peterborough, Ontario, Canada.
authors: Donald
authors: D
authors: Mackay
authors: Chemical Properties Research Group, Department of Chemistry, Trent University, Peterborough, Ontario, Canada.|Department of Chemistry, Queens University, Kingston, Ontario, Canada.
authors: Alena K D
authors: AKD
authors: Celsie
authors: Chemical Properties Research Group, Department of Chemistry, Trent University, Peterborough, Ontario, Canada.|Department of Chemistry, Queens University, Kingston, Ontario, Canada.
authors: J Mark
authors: JM
authors: Parnis
authors: L.S. McCarty Scientific Research Consulting, Newmarket, Ontario, Canada.
authors: Lynn S
authors: LS
authors: McCarty
authors: Arnot Research and Consulting (ARC), Toronto, Ontario, Canada.|Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada.
authors: Jon A
authors: JA
authors: Arnot
authors: Dow Corning Corporation, Health and Environmental Sciences, Auburn, Michigan, USA.
authors: David E
authors: DE
authors: Powell
mesh_terms: D004781:Environmental Exposure; D008962:Models, Theoretical; D009930:Organic Chemicals / Q000737:chemistry / Q000633:toxicity; D013997:Time Factors; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity
chemical_list: D009930:Organic Chemicals; D014874:Water Pollutants, Chemical
keywords: Aquatic toxicology; Bioconcentration; Toxicokinetics