Aquatic Contaminants Research Division, Environment and Climate Change Canada, 105 McGill street, 7th Floor, Montréal, QC H2Y 2E7, Canada.
Aquatic Contaminants Research Division, Environment and Climate Change Canada, 105 McGill street, 7th Floor, Montréal, QC H2Y 2E7, Canada.
Ecotoxicol Environ Saf. 2022 Aug;241:113793. doi: 10.1016/j.ecoenv.2022.113793. Epub 2022 Jun 24.
Rare earth elements (REEs) are considered critical elements for technology and their extraction through mining activities is expected to increase in the future. Due to their chemical similarities, they often co-occur in minerals and thus their ecotoxicity should be assessed as a group/family. However, the available ecotoxicological studies focused mainly on the evaluation of the potential toxicological impacts of individual REEs rather than their mixtures. The aim of this study was therefore to evaluate the toxicity of a representative mixture of five REEs (La, Ce, Pr, Nd and Sm) spanning environmentally relevant concentrations ranging from 0.05X (29 µg REEs L) to 5X (2926 µg REEs L) to the test organism, Hydra vulgaris, at the morphological, reproductive and regenerative levels. The data showed that lethality occurred at concentrations near (2.5 fold) to those inducing sublethal effects after chronic exposure of 7 days. The mixture affected reproduction and head regeneration and even lethality at concentrations even below those reported at environmental concentration (0.5X = 293 µg REEs L) in lakes. This suggests that REEs concentrations found in lakes near mining activities could disrupt regeneration and impair embryonic development. Our data also revealed that combining the 5 REEs results in an antagonistic effect, suggesting that those elements share the same receptor and that low molecular weight and high radius elements (approaching iron) were less toxic. Taken together, hydra could be used as a sensitive model organism for the assessment of aquatic ecotoxicological risks of REE mixtures but further analyses of biochemical and gene expressions should improve our understanding of the long-term effects of REEs mixtures.
稀土元素(REEs)被认为是技术的关键元素,预计未来其开采活动将增加。由于它们的化学性质相似,它们经常在矿物质中共存,因此应该作为一个群体/家族来评估它们的生态毒性。然而,现有的生态毒理学研究主要集中在评估单个 REEs 的潜在毒理学影响上,而不是它们的混合物。因此,本研究的目的是评估一组具有代表性的五种 REEs(La、Ce、Pr、Nd 和 Sm)混合物的毒性,这些 REEs 的浓度范围从环境相关浓度的 0.05X(29μgREEs/L)到 5X(2926μgREEs/L),用于测试生物 Hydra vulgaris,在形态、生殖和再生水平上。数据表明,在慢性暴露 7 天后,接近(2.5 倍)诱导亚致死效应的浓度时会发生致死率。该混合物影响了繁殖和头部再生,甚至在浓度甚至低于环境浓度(0.5X=293μgREEs/L)的湖泊中也会导致致死率。这表明在采矿活动附近的湖泊中发现的 REEs 浓度可能会破坏再生并损害胚胎发育。我们的数据还表明,将 5 种 REEs 结合在一起会产生拮抗作用,这表明这些元素共享相同的受体,并且低分子量和大半径元素(接近铁)的毒性较小。总之,水螅可以作为评估 REEs 混合物对水生生态毒性风险的敏感模型生物,但进一步的生化和基因表达分析应能提高我们对 REEs 混合物长期影响的理解。