Université de Lorraine, CNRS, LIEC, F-57000 Metz, France; LTSER-Zone Atelier Moselle, F-57000 Metz, France.
Université de Lorraine, CNRS, LIEC, F-57000 Metz, France; Université Catholique de l'Ouest, Laboratoire Mer, Biologie des Organismes, Stress, Santé, Environnement (BIOSSE), F-49000 Angers Cedex 01, France.
Sci Total Environ. 2023 Dec 20;905:167302. doi: 10.1016/j.scitotenv.2023.167302. Epub 2023 Sep 22.
Rare earth elements (REE) are emerging contaminants due to their increased use in diverse applications including cutting-edge and green-technologies. Their environmental concerns and contradicting results concerning their biological effects require an extensive understanding of REE ecotoxicology. Thus, we have studied the fate, bioaccumulation and biological effects of three representative REE, neodymium (Nd), gadolinium (Gd) and ytterbium (Yb), individually and in mixture, using the freshwater bivalve Corbicula fluminea. The organisms were exposed for 96 h at 1 mg L REE in the absence and presence of dissolved organic matter (DOM) reproducing an environmental contamination. Combined analysis of the fate, distribution and effects of REE at tissue and subcellular levels allowed a comprehensive understanding of their behaviour, which would help improving their environmental risk assessment. The bivalves accumulated significant concentrations of Nd, Gd and Yb, which were decreased in the presence of DOM likely due to the formation of REE-DOM complexes that reduced REE bioavailability. The accumulation of Nd, Gd and Yb differed between tissues, with gills > digestive gland ≥ rest of soft tissues > hemolymph. In the gills and in the digestive gland, Nd, Gd and Yb were mostly (>90 %) distributed among metal sensitive organelles, cellular debris and detoxified metal-rich granules. Gadolinium, Yb and especially Nd decreased lysosome size in the digestive gland and disturbed osmo- and iono-regulation of C. fluminea by decreasing Na concentrations in the hemolymph and Ca ATPase activity in the gills. Individual and mixed Nd, Gd and Yb exhibited numerous similarities and some differences in terms of fate, accumulation and biological effects, possibly because they have common abiotic and biotic ligands but different affinities for the latter. In most cases, individual and mixed effects of Nd, Gd, Yb were similar suggesting that additivity approach is suitable for the environmental risk assessment of REE mixtures.
稀土元素（REE）由于其在包括尖端技术和绿色技术在内的各种应用中的使用增加而成为新兴污染物。它们对环境的关注以及关于其生物效应的相互矛盾的结果，需要对 REE 生态毒理学有广泛的了解。因此，我们使用淡水双壳类贻贝 Corbicula fluminea 研究了三种代表性 REE（钕（Nd）、钆（Gd）和镱（Yb））单独和混合时的命运、生物积累和生物效应。在不存在和存在溶解有机物（DOM）的情况下，将生物体在 1mg/L REE 下暴露 96 小时，模拟环境污染。REE 在组织和亚细胞水平上的命运、分布和效应的综合分析使我们能够全面了解它们的行为，这将有助于改善它们的环境风险评估。双壳类动物积累了大量的 Nd、Gd 和 Yb，而在 DOM 存在的情况下，这些元素的含量降低，这可能是由于 REE-DOM 复合物的形成降低了 REE 的生物利用度。Nd、Gd 和 Yb 的积累在组织之间存在差异，其中鳃>消化腺≥其余软组织>血淋巴。在鳃和消化腺中，Nd、Gd 和 Yb 主要分布在金属敏感细胞器、细胞碎片和解毒的富含金属的颗粒中。在消化腺中，Gd、Yb 尤其是 Nd 降低了溶酶体的大小，并通过降低血淋巴中的 Na 浓度和鳃中的 Ca ATP 酶活性来干扰 C. fluminea 的渗透和离子调节。单独和混合的 Nd、Gd 和 Yb 在命运、积累和生物效应方面表现出许多相似之处和一些差异，这可能是因为它们具有共同的非生物和生物配体，但对后者的亲和力不同。在大多数情况下，Nd、Gd、Yb 的单独和混合效应相似，这表明加性方法适用于 REE 混合物的环境风险评估。
