Rare earth elements (REEs) are extensively utilized in industry, agriculture, advanced materials and other fields, leading to their dispersion in water bodies as emerging contaminants. Meanwhile, the coexistence of REEs and heavy metals (HMs) has become a novel form of water contamination (REE-HM co-contamination), though scientists have limited understanding of its hazards. Here, Chlorococcum sp. cultured in Taihu Lake water was selected to examine the effects of low-dose lanthanum(III) [La(III)] on its growth and HM accumulation. Low-dose La(III) (0.5-30 μg/L) promoted algal growth and increased the contents of Cd (136.7%), Pb (92.0%), and Cr (84.3%), along with the bioconcentration factor of Cd (135.5%), Pb(91.7%), and Cr(84.0%) in Chlorococcum sp. These changes were attributed to La(III)-induced adaptive physiological regulations, including essential element uptake, photosynthesis, and antioxidant enzyme activities, achieved through La(III)-enhanced clathrin-mediated endocytosis. In summary, low-dose La(III) increased the growth and HM accumulation of Chlorococcum sp. in REE-HM co-contaminated water. This phenomenon amplified the toxicity of Chlorococcum sp., causing the HM accumulation in predators in the grazing food chain and posing a new threat to aquatic ecosystems.

中文翻译：

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暴露于低剂量镧 （III） 的 Chlorococcum sp. 的扩增生长和重金属毒性


稀土元素 （REE） 广泛用于工业、农业、先进材料等领域，导致它们作为新兴污染物分散在水体中。与此同时，稀土元素和重金属 （HMs） 的共存已成为一种新型的水污染（REE-HM 共污染），尽管科学家对其危害的了解有限。在这里，选择在太湖水中培养的 Chlorococcum sp. 来检查低剂量镧 （III） [La（III）] 对其生长和 HM 积累的影响。低剂量 La（III） （0.5-30 μg/L） 促进藻类生长，增加了氯球菌中 Cd （136.7%） 、 Pb （92.0%） 和 Cr （84.3%） 的含量，以及 Cd （135.5%） 、 Pb （91.7%） 和 Cr （84.0%） 的生物富集因子。这些变化归因于 La（III） 诱导的适应性生理调节，包括必需元素摄取、光合作用和抗氧化酶活性，通过 La（III） 增强的网格蛋白介导的内吞作用实现。总之，低剂量 La（III） 增加了 REE-HM 共污染水中氯球菌属的生长和 HM 积累。这种现象放大了 Chlorococcum sp. 的毒性，导致 HM 在放牧食物链中的捕食者体内积累，并对水生生态系统构成新的威胁。