Great Lakes Toxicology and Ecology Division, Center for Computational Toxicology and Ecology, US Environmental Protection Agency, Office of Research and Development, Duluth, Minnesota, USA.
Environ Toxicol Chem. 2022 Sep;41(9):2078-2094. doi: 10.1002/etc.5390. Epub 2022 Aug 3.
The results of a series of experiments on the acute toxicity of major geochemical ions (Na , K , Ca , Mg , Cl , SO , HCO /CO ) to fathead minnows (Pimephales promelas) are reported. Tests of individual major ion salts in various dilution waters demonstrated that the toxicities of Na, Mg, and K salts decrease as the overall ion content of the dilution water increases. For Na and Mg salts, this is attributable to Ca content as previously reported for Ceriodaphnia dubia. For K salts, the cause is unclear, but it is not due to Na as reported for C. dubia. In an unregulated test at high pH (9.3), NaHCO was also found to be twice as toxic compared to when the pH was reduced to 8.4. Experiments with binary salt mixtures indicated the existence of multiple independent mechanisms of action. These include K-specific toxicity and Ca/Mg-specific toxicity previously reported for C. dubia, but also apparent toxicities related to SO and to high pH/alkalinity in CO /HCO -dominated exposures. Previous work with C. dubia also suggested a general ion toxicity involving all ions that was correlated with osmolarity. For fathead minnow, similar correlations were observed, but multiple mechanisms were indicated. At higher Ca, this general toxicity could be attributable to osmotic effects, but at lower Ca, osmolarity may be more a covariate than a cause, with this toxicity being related to a combined effect of ions other than via osmolarity. Environ Toxicol Chem 2022;41:2078-2094. © 2022 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
本文报道了一系列关于主要地球化学离子（Na+、K+、Ca2+、Mg2+、Cl−、SO2−4、HCO3−/CO32−）对黑头呆鱼（Pimephales promelas）急性毒性的实验结果。在不同稀释水中测试单一主要离子盐表明，随着稀释水中总离子含量的增加，Na+、Mg2+和 K+盐的毒性降低。对于 Na 和 Mg 盐，这归因于 Ca 含量，如先前对 Ceriodaphnia dubia 的报道。对于 K 盐，原因尚不清楚，但与 C. dubia 报道的原因不同，不是因为 Na。在高 pH（9.3）的未调节测试中，还发现 NaHCO3 的毒性是 pH 降低至 8.4 时的两倍。二元盐混合物实验表明存在多种独立的作用机制。这些机制包括先前报道的 C. dubia 中存在的 K 特异性毒性和 Ca/Mg 特异性毒性，但也存在与 SO 和 CO32−/HCO3−占主导的暴露相关的高 pH/碱性有关的明显毒性。先前对 C. dubia 的研究还表明，涉及所有离子的一般离子毒性与渗透压有关。对于黑头呆鱼，观察到类似的相关性，但表明存在多种机制。在较高的 Ca 浓度下，这种一般毒性可能归因于渗透压效应，但在较低的 Ca 浓度下，渗透压可能更多地是一个协变量而不是原因，这种毒性与除渗透压以外的离子的联合效应有关。环境毒理化学 2022；41:2078-2094。©2022 SETAC。本文已由美国政府雇员贡献，其工作在美国属于公有领域。
