In aquatic toxicology, a toxicity-prediction model is generally deemed acceptable if its predicted median lethal concentrations (LC50 values) or median effect concentrations (EC50 values) are within a factor of 2 of their paired, observed LC50 or EC50 values. However, that rule of thumb is based on results from only two studies: multiple LC50 values for the fathead minnow (Pimephales promelas) exposed to Cu in one type of exposure water, and multiple EC50 values for Daphnia magna exposed to Zn in another type of exposure water. We tested whether the factor-of-2 rule of thumb also is supported in a different dataset in which D. magna were exposed separately to Cd, Cu, Ni, or Zn. Overall, the factor-of-2 rule of thumb appeared to be a good guide to evaluating the acceptability of a toxicity model’s underprediction or overprediction of observed LC50 or EC50 values in these acute toxicity tests.
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Di Toro DM, Allen HE, Bergman HL, Meyer JS, Paquin PR, Santore RC (2001) Biotic ligand model of the acute toxicity of metals. 1. Technical basis. Environ Toxicol Chem 20:2383–2396
Erickson RJ, Benoit DA, Mattson VR (1987) A prototype toxicity factors model for site-specific copper water quality criteria. Revised September 5, 1996. EPA/600/X-87/290. U.S. Environmental Protection Agency, Environmental Research Laboratory-Duluth, Duluth, MN, USA
Meyer JS, Adams WJ, DeForest DK, Dwyer RL, Gensemer RW, Gorsuch JW, Johnston RK, Santore RC, Van Genderen E (2012) Letter to the editor: water chemistry matters in metal-toxicity papers. Environ Toxicol Chem 31:689–690
Meyer JS, Ranville JF, Pontasch M, Gorsuch JW, Adams WJ (2015) Acute toxicity of binary and ternary mixtures of Cd, Cu, and Zn to Daphnia magna. Environ Toxicol Chem 34:799–808
Santore RC, Ryan AC (2015) Development and application of a multimetal multibiotic ligand model for assessing aquatic toxicity of metal mixtures. Environ Toxicol Chem 34:777–787
Santore RC, Di Toro DM, Paquin PR, Allen HE, Meyer JS (2001) Biotic ligand model of the acute toxicity of metals. 2. Application to acute copper toxicity in freshwater fish and Daphnia. Environ Toxicol Chem 20:2397–2402
Traudt EM, Ranville JF, Smith A, Meyer JS (2016) A test of the additivity of acute toxicity of binary-metal mixtures of Ni with Cd, Cu, and Zn to Daphnia magna, using the inflection point of the concentration-response curves. Environ Toxicol Chem 35:1843–1851
Traudt EM, Ranville JF, Meyer JS (2017) Effect of age on acute toxicity of cadmium, copper, nickel, and zinc in individual-metal exposures to Daphnia magna neonates. Environ Toxicol Chem 36:113–119
USEPA (U.S. Environmental Protection Agency) (1980) Ambient water quality criteria for copper. EPA 440/5-80-036. U.S. Environmental Protection Agency, Washington, DC
USEPA (U.S. Environmental Protection Agency) (2002) Methods for measuring the acute toxicity of effluents and receiving waters to freshwater and marine organisms. EPA-821-R-02-012 5th edn. U.S. Environmental Protection Agency, Washington, DC
This study was funded by the National Institute of Environmental Health Sciences (Grant No. 1R01ES024358-01), International Copper Association, International Zinc Association, NiPERA, Inc., and Rio Tinto. The authors declare that they have no conflict of interest.
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Meyer, J.S., Traudt, E.M. & Ranville, J.F. Is the Factor-of-2 Rule Broadly Applicable for Evaluating the Prediction Accuracy of Metal-Toxicity Models?. Bull Environ Contam Toxicol 100, 64–68 (2018). https://doi.org/10.1007/s00128-017-2258-4
- Daphnia magna
- Fathead minnow