EHS Support, Waterbury, Vermont, USA.
EHS Support, Hinesburg, Vermont, USA.
Environ Toxicol Chem. 2022 Feb;41(2):396-409. doi: 10.1002/etc.5259. Epub 2022 Jan 18.
The derivation of protective values for aquatic life can be enhanced by the development and use of bioavailability models. Recent advances to metals bioavailability modeling are applicable to other analyte groups and should be widely considered. We conducted a meta-analysis of the available aquatic toxicity literature for fluoride to evaluate the utility of hardness, alkalinity, and chloride as toxicity-modifying factors (TMFs) in empirical bioavailability models of freshwater taxa. The resulting optimal multiple linear regression model predicting acute fluoride toxicity to the invertebrate Hyalella azteca included all three TMFs (observed vs. predicted 50% lethal concentrations, R = 0.88) and the optimal model predicting toxicity to the fish Oncorhynchus mykiss included alkalinity and hardness (R = 0.37). At >20 mg/L chloride, the preliminary final acute values for fluoride were within 1 order of magnitude and ranged from approximately 18.1 to 56.3 mg/L, depending on water chemistry. Sensitivity of H. azteca to low-chloride conditions increased model uncertainty when chloride was <20 mg/L. Because of limited toxicity data, chronic bioavailability models were not developed, and final chronic values were derived using an acute-to-chronic ratio (ACR) approach. Accounting for TMFs, the geometric mean ACR was 5.4 for fish and invertebrate taxa (n = 6). The present assessment highlights the need to expand bioavailability modeling to include inorganic anions, particularly fluoride, and demonstrates that existing promulgated protective values for fluoride are likely overly conservative. More toxicological studies are recommended to further refine multivariate empirical bioavailability models for inorganic anions. Environ Toxicol Chem 2022;41:396-409. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
通过开发和利用生物有效性模型，可以提高水生生物保护值的推导。金属生物有效性建模的最新进展适用于其他分析物组，应广泛考虑。我们对氟化物的现有水生毒性文献进行了荟萃分析，以评估硬度、碱度和氯作为淡水分类群经验生物有效性模型中毒性修饰因子（TMF）的效用。预测无脊椎动物 Hyalella azteca 急性氟毒性的最佳多元线性回归模型包括所有三个 TMF（观察值与预测值的 50%致死浓度，R = 0.88），预测鱼类 Oncorhynchus mykiss 毒性的最佳模型包括碱度和硬度（R = 0.37）。在 >20 mg/L 氯条件下，氟化物的初步最终急性值在一个数量级内，范围约为 18.1 至 56.3 mg/L，具体取决于水化学。当氯 <20 mg/L 时，H. azteca 对低氯条件的敏感性增加了模型的不确定性。由于毒性数据有限，因此没有开发慢性生物有效性模型，并且使用急性到慢性比值（ACR）方法得出最终慢性值。考虑到 TMF，鱼类和无脊椎动物分类群的几何平均 ACR 为 5.4（n = 6）。本评估强调需要扩展生物有效性模型以包括无机阴离子，特别是氟化物，并表明现有的氟化物保护值可能过于保守。建议进行更多的毒理学研究，以进一步完善无机阴离子的多元经验生物有效性模型。环境毒理学与化学 2022；41:396-409。© 2021 作者。环境毒理学与化学由 Wiley 期刊公司代表 SETAC 出版。
