CNRS UMR 7360, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Université de Lorraine, Metz 57070, France; Marine Research Institute (IIM-CSIC), Eduardo Cabello 6, Vigo 36208, Spain.
Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia; Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, 51005 Tartu, Estonia.
Sci Total Environ. 2019 Apr 15;661:276-284. doi: 10.1016/j.scitotenv.2019.01.155. Epub 2019 Jan 15.
Lanthanide (LNs) release into the environment is expected to greatly increase in the coming years due to a high demand for new technologies. However there is a gap in the ecological risk assessment of these metals because most of the ecotoxicological studies have been performed with only one element, although they are usually found in nature as a group. This research evaluated the effects of mixtures of three lanthanides, cerium (Ce), gadolinium (Gd), and lutetium (Lu), representative of the light, middle and heavy rare earth elements, respectively, on seven aquatic species (A. fischeri, R. subcapitata, C. vulgaris, B. calyciflorus, H. incongruens, D. magna and D. rerio). Lanthanide content decreased over time in all toxicity test media and it was observed that LN sedimentation starts at the beginning of the tests with a steep decline of the available LN amount. Potential toxic effects of LNs were observed only in five species of the seven studied, predominantly in the unicellular organism (A. fischeri) and in the organisms belonging to the lower trophic levels (R. subcapitata and B. calyciflorus). The multi-toxicity approach performed in this study showed synergistic effects in tests performed with the bacteria A. fischeri and the algae R. subcapitata, and antagonistic effects for the rotifer B. calyciflorus. Although predicting the response of aquatic organisms exposed to multi-elements is not an easy task and can be masked by potential interactions with other compounds or even by nutrient removal. The variation in toxic action among species observed in this study reveals that lanthanide interaction in toxicity mechanisms should not be discarded, and supports that further studies with LN mixtures are required to properly understand their toxic behaviour in nature ecosystems.
由于对新技术的高需求，预计未来几年镧系元素（Ln）将大量释放到环境中。然而，这些金属的生态风险评估存在空白，因为大多数生态毒理学研究仅使用一种元素进行，尽管它们通常在自然界中作为一组存在。本研究评估了三种镧系元素混合物（铈（Ce）、钆（Gd）和镥（Lu））对七种水生物种（发光菌（A. fischeri）、微囊藻（R. subcapitata）、菹草（C. vulgaris）、莕菜（B. calyciflorus）、虹鳉（H. incongruens）、大型蚤（D. magna）和斑马鱼（D. rerio））的影响。在所有毒性测试介质中，镧系元素的含量随时间的推移而降低，并且观察到镧系元素的沉降从测试开始时就开始，可用镧系元素的数量急剧下降。只有在七种研究物种中的五种物种中观察到镧系元素的潜在毒性效应，主要在单细胞生物（发光菌（A. fischeri））和属于较低营养级的生物（微囊藻（R. subcapitata）和莕菜（B. calyciflorus））中观察到。本研究中采用的多毒性方法在与细菌发光菌（A. fischeri）和藻类微囊藻（R. subcapitata）进行的测试中显示出协同效应，而对轮虫莕菜（B. calyciflorus）则表现出拮抗效应。尽管预测暴露于多种元素的水生生物的反应不是一项简单的任务，并且可能会被与其他化合物的潜在相互作用甚至被养分去除所掩盖。在本研究中观察到的物种间毒性作用的变化表明，不应排除镧系元素在毒性机制中的相互作用，并支持需要进一步进行镧系元素混合物的研究，以正确理解它们在自然生态系统中的毒性行为。
