Regulatory jurisdictions worldwide are increasingly incorporating bioavailability-based toxicity models into development of protective values (PVALs) for freshwater and saltwater aquatic life (e.g., water quality criteria, standards, and/or guidelines) for metals. Use of such models for regulatory purposes should be contingent on their ability to meet performance criteria as specified through a model-validation process. Model validation generally involves an assessment of a model's appropriateness, relevance, and accuracy. We review existing guidance for validation of bioavailability-based toxicity models, recommend questions that should be addressed in model-validation studies, discuss model study type and design considerations, present several new ways to evaluate model performance in validation studies, and suggest a framework for use of model validation in PVAL development. We conclude that model validation should be rigorous but flexible enough to fit the user's purpose. Although a model can never be fully validated to a level of zero uncertainty, it can be sufficiently validated to fit a specific purpose. Therefore, support (or lack of support) for a model should be presented in such a way that users can choose their own level of acceptability. We recommend that models be validated using experimental designs and endpoints consistent with the data sets that were used to parameterize and calibrate the model and validated across a broad range of geographically and ecologically relevant water types. Environ Toxicol Chem 2019;39:101-117. © 2019 SETAC.

中文翻译：

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基于生物利用度的金属毒性模型的验证。


世界各地的监管机构越来越多地将基于生物利用度的毒性模型纳入淡水和咸水水生生物的金属保护值（PVAL）（例如水质标准、标准和/或指南）的开发中。将此类模型用于监管目的应取决于其满足通过模型验证过程指定的性能标准的能力。模型验证通常涉及对模型的适当性、相关性和准确性的评估。我们回顾了基于生物利用度的毒性模型验证的现有指南，提出了模型验证研究中应解决的问题，讨论了模型研究类型和设计注意事项，提出了在验证研究中评估模型性能的几种新方法，并提出了一个框架在 PVAL 开发中使用模型验证。我们的结论是，模型验证应该严格但足够灵活，以满足用户的目的。尽管模型永远无法完全验证到零不确定性水平，但可以对其进行充分验证以适合特定目的。因此，对模型的支持（或缺乏支持）应该以用户可以选择自己的可接受程度的方式呈现。我们建议使用与用于参数化和校准模型的数据集一致的实验设计和终点来验证模型，并在广泛的地理和生态相关水类型中进行验证。环境毒理学化学2019；39：101-117。 © 2019 SETAC。