European Precious Metals Federation, Brussels, Belgium.
ARCHE Consulting, Ghent (Wondelgem), Belgium.
Environ Toxicol Chem. 2019 Aug;38(8):1701-1713. doi: 10.1002/etc.4463. Epub 2019 Jul 25.
Silver (Ag) salts have been shown to be highly toxic to freshwater organisms. There is nevertheless still a high level of uncertainty as to the aquatic effects of Ag nanoparticles (AgNPs), and how these relate to the effects of soluble Ag salts. As part of the substance evaluation for Ag of the European Union Registration, Evaluation, Authorisation, and Restriction of Chemicals regulation, we have generated new data to justify read-across from soluble Ag salts to AgNPs. The aquatic toxicity to algae growth and Daphnia magna reproduction, fate, and behavior of AgNO versus AgNPs were tested and compared. Chloride salts in the test media were replaced with equimolar concentrations of nitrate salts. Total Ag, "conventionally" dissolved Ag (0.45 µm), and "truly" dissolved Ag (3 kDa) were determined. Algae were the most sensitive test species to AgNO (10% effect concentration [EC10] 0.10 µg Ag/L) when expressed as conventionally dissolved Ag. The corresponding value for AgNPs was 0.26 µg/L. For D. magna reproduction, the lowest EC10 values were 3.49 µg Ag/L for AgNO and 33.4 µg Ag/L for AgNPs. Using measured Ag concentrations, AgNO was experimentally shown to be more toxic than AgNPs for all Ag fractions. We explain these observations by a different dissolution behavior of AgNO versus AgNPs. The results provide experimental confirmation that AgNO can be used as a conservative estimate for the aquatic effects of AgNPs at comparable Ag concentrations. Environ Toxicol Chem 2019;38:1701-1713. © 2019 SETAC.
银（Ag）盐已被证明对淡水生物具有高度毒性。然而，对于银纳米颗粒（AgNPs）的水生效应以及这些效应如何与可溶性 Ag 盐的效应相关，仍然存在高度的不确定性。作为欧盟注册、评估、授权和限制化学品法规中 Ag 物质评估的一部分，我们生成了新的数据，以证明从可溶性 Ag 盐到 AgNPs 的类推是合理的。测试并比较了 AgNO 对藻类生长和大型溞繁殖的水生毒性、命运和行为，以及 AgNPs。测试介质中的氯化物盐用等摩尔浓度的硝酸盐盐替代。测定了总 Ag、“常规”溶解 Ag（0.45μm）和“真正”溶解 Ag（3kDa）。当以常规溶解 Ag 表示时，藻类是对 AgNO 最敏感的测试物种（10%效应浓度[EC10]为 0.10μg Ag/L）。AgNPs 的相应值为 0.26μg/L。对于 D. magna 繁殖，AgNO 的最低 EC10 值为 3.49μg Ag/L，AgNPs 的最低 EC10 值为 33.4μg Ag/L。使用测量的 Ag 浓度，实验表明，对于所有 Ag 馏分，AgNO 比 AgNPs 更具毒性。我们通过 AgNO 与 AgNPs 不同的溶解行为来解释这些观察结果。这些结果提供了实验证实，即在可比的 Ag 浓度下，AgNO 可用于保守估计 AgNPs 的水生效应。环境毒理化学 2019；38：1701-1713。©2019 SETAC。
