Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China; Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education of China and Inner Mongolia Autonomous Region, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China.
Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China; Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education of China and Inner Mongolia Autonomous Region, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China.
Sci Total Environ. 2024 Dec 15;956:177305. doi: 10.1016/j.scitotenv.2024.177305. Epub 2024 Nov 6.
Rare earth elements (REEs) have raised significant environmental contamination concerns, yet the combined toxicity of REE mixtures remains inadequately understood. In this study, acute toxicity of individual, binary and ternary mixtures of lanthanum (La), cerium (Ce), and dysprosium (Dy) on neonatal Daphnia magna was investigated. Dy exhibited the greatest toxicity on neonatal Daphnia magna, followed by La and Ce. The concentration addition (CA) model was superior to the independent action (IA) model for predicting the toxicity of binary mixtures. The CA model indicated additive effects for LaCe mixture and antagonistic effects for LaDy and CeDy mixtures. In contrast, IA model suggested synergistic interactions for LaCe and LaDy mixtures, with antagonistic effects for CeDy mixture when considering dissolved concentration and synergistic effects when considering free-ion concentration. The nonadditive interactions and deviation parameters from the prediction of binary mixture toxicity were assessed by using MixTox model. The ternary mixture of LaCeDy exhibited antagonistic effects on Daphnia magna, and IA model slightly outperformed CA model. Overall, the type of combined toxicity in REE mixtures is influenced by constituents in the mixture and concentration levels. These findings provide scientific basis for the toxicological assessment, risk evaluation and pollution control of REE mixtures. ENVIRONMENTAL IMPLICATION: Rare earth elements (REEs) level is increasing in water environment due to wide use and exploitation. However, currently, we know little about the difference of REEs toxicity and combined toxicity of mixture to aquatic organism, which limited the assessment of toxicity and hazard risk of REEs in natural water. Here, this study demonstrates the acute toxicity of individual, binary and ternary mixtures of lanthanum, cerium, and dysprosium on neonatal Daphnia magna according to the measured data and predicted model, identifying the influence factors for combined toxicity. This discovery offers new insights for the assessment and prediction of REEs toxicity.
稀土元素 (REEs) 引起了人们对环境污染的极大关注，但对 REE 混合物的综合毒性仍了解不足。在这项研究中，研究了镧 (La)、铈 (Ce) 和镝 (Dy) 单一、二元和三元混合物对新生溞 (Daphnia magna) 的急性毒性。结果表明，Dy 对新生溞的毒性最大，其次是 La 和 Ce。浓度加和 (CA) 模型优于独立作用 (IA) 模型，可用于预测二元混合物的毒性。CA 模型表明，LaCe 混合物具有相加作用，LaDy 和 CeDy 混合物具有拮抗作用。相反，IA 模型表明 LaCe 和 LaDy 混合物具有协同作用，而 CeDy 混合物在考虑溶解浓度时表现出拮抗作用，在考虑游离离子浓度时表现出协同作用。通过使用 MixTox 模型评估了二元混合物毒性预测的非加性相互作用和偏离参数。LaCeDy 三元混合物对溞表现出拮抗作用，IA 模型略优于 CA 模型。总之，REE 混合物中联合毒性的类型受混合物中成分和浓度水平的影响。这些发现为 REE 混合物的毒理学评估、风险评价和污染控制提供了科学依据。
由于广泛的使用和开采，稀土元素 (REEs) 在水环境中的含量正在增加。然而，目前我们对 REE 对水生生物的毒性和混合物的综合毒性差异知之甚少，这限制了对天然水中 REE 毒性和危害风险的评估。在这里，根据实测数据和预测模型，研究了镧、铈和镝单一、二元和三元混合物对新生溞的急性毒性，确定了联合毒性的影响因素。这一发现为 REE 毒性的评估和预测提供了新的见解。
