Bayer, Monheim, Germany.
Rifcon, Hirschberg an der Bergstrasse, Germany.
Environ Toxicol Chem. 2022 Jul;41(7):1778-1787. doi: 10.1002/etc.5346. Epub 2022 May 21.
In pesticide risk assessment, regulatory acceptable concentrations for surface water bodies (RACsw,ch) are used that are derived from standard studies with continuous exposure of organisms to a test compound for days or months. These RACsw,ch are compared with the maximum tested concentration of more realistic exposure scenarios. However, the actual exposure duration could be notably shorter (e.g., hours) than the standard study, which intentionally leads to an overly conservative Tier 1 risk assessment. This discrepancy can be addressed in a risk assessment using the time-weighted average concentration (TWAc). In Europe, the applicability of TWAc for a particular risk assessment is evaluated using a complex decision scheme, which has been controversial; thus we propose an alternative approach: We used TWAc-check (which is based on the idea that the TWAc concept is just a model for aquatic risk assessment) to test whether the use of a TWAc is appropriate for such assessment. The TWAc-check method works by using predicted-measured diagrams to test how well the TWAc model predicts experimental data from peak exposure experiments. Overestimated effects are accepted because the conservatism of the TWAc model is prioritized over the goodness of fit. We illustrate the applicability of TWAc-check by applying it to various data sets for different species and substances. We demonstrate that the applicability is case dependent. Specifically, TWAc-check correctly identifies that the use of TWAc is not appropriate for early onset of effects or delayed effects. The proposed concept shows that the time window is a decisive factor as to whether or not the model is acceptable and that this concept can be used as a potential refinement option prior to the use of toxicokinetic-toxicodynamic models. Environ Toxicol Chem 2022;41:1778-1787. © 2022 Bayer AG. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
在农药风险评估中，使用了针对地表水的监管可接受浓度（RACsw，ch），这些浓度是通过对生物体进行连续暴露于测试化合物数天或数月的标准研究得出的。这些 RACsw，ch 与更现实的暴露场景下测试的最大浓度进行比较。然而，实际暴露时间可能明显短于标准研究（例如，数小时），这导致了过于保守的第一级风险评估。可以使用时间加权平均浓度（TWAc）在风险评估中解决这个问题。在欧洲，使用 TWAc 进行特定风险评估的适用性是使用复杂的决策方案进行评估的，这一直存在争议；因此，我们提出了一种替代方法：我们使用 TWAc-check（基于 TWAc 概念只是一种水生风险评估模型的想法）来测试使用 TWAc 是否适合这种评估。TWAc-check 方法通过使用预测-测量图来测试 TWAc 模型对峰值暴露实验的实验数据的预测能力。接受高估的效果，因为优先考虑 TWAc 模型的保守性而不是拟合优度。我们通过将 TWAc-check 应用于不同物种和物质的各种数据集来说明其适用性。我们证明了适用性取决于具体情况。具体来说，TWAc-check 正确地表明，TWAc 的使用不适合早期效应或延迟效应。所提出的概念表明，时间窗口是模型是否可接受的决定性因素，并且该概念可以在使用毒代动力学-毒效动力学模型之前用作潜在的细化选项。Environ Toxicol Chem 2022;41:1778-1787. © 2022 拜耳公司。环境毒理学和化学由 Wiley Periodicals LLC 代表 SETAC 出版。
