Yu Le, Wang Zhuang, Wang De-Gao
School of Environmental Science and Engineering, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, Nanjing, 210044, People's Republic of China.
College of Environmental Sciences and Engineering, Dalian Maritime University, Dalian, 116026, People's Republic of China.
Environ Sci Pollut Res Int. 2023 May;30(22):63109-63120. doi: 10.1007/s11356-023-26522-3. Epub 2023 Mar 23.
Layered double hydroxide (LDH) nanomaterials are utilized extensively in numerous fields because of their distinctive structural properties. It is critical to understand the environmental behavior and toxicological effects of LDHs to address potential concerns caused by their release into the environment. In this work, the toxicological effects of two typical LDHs (Mg-Al-LDH and Zn-Al-LDH) on freshwater green algae (Scenedesmus obliquus) and the main affecting factors were examined. The Zn-Al-LDH exhibited a stronger growth inhibition toxicity than the Mg-Al-LDH in terms of median effect concentration. This toxicity difference was connected to the stability of particle dispersion in water and the metallic composition of LDHs. The contribution of the dissolved metal ions to the overall toxicity of the LDHs was lower than that of their particulate forms. Moreover, the joint toxic action of different dissolved metal ions in each LDH belonged to additive effects. The Mg-Al-LDH induced a stronger oxidative stress effect in algal cells than the Zn-Al-LDH, and mitochondrion was the main site of LDH-induced production of reactive oxygen species. Scanning electron microscope observation indicated that both LDHs caused severe damage to the algal cell surface. At environmentally relevant concentrations, the LDHs exhibited joint toxic actions with two co-occurring contaminants (oxytetracycline and nano-titanium dioxide) on S. obliquus in an additive manner mainly. These findings emphasize the impacts of the intrinsic nature of LDHs, the aqueous stability of LDHs, and other environmental contaminants on their ecotoxicological effects.
层状双氢氧化物（LDH）纳米材料因其独特的结构性质而在众多领域得到广泛应用。了解LDHs的环境行为和毒理学效应对于解决其释放到环境中可能引起的潜在问题至关重要。在这项工作中，研究了两种典型的LDHs（Mg-Al-LDH和Zn-Al-LDH）对淡水绿藻（斜生栅藻）的毒理学效应及其主要影响因素。就半数效应浓度而言，Zn-Al-LDH比Mg-Al-LDH表现出更强的生长抑制毒性。这种毒性差异与颗粒在水中的分散稳定性以及LDHs的金属组成有关。溶解态金属离子对LDHs整体毒性的贡献低于其颗粒态。此外，每种LDH中不同溶解态金属离子的联合毒性作用属于相加效应。Mg-Al-LDH比Zn-Al-LDH在藻类细胞中诱导更强的氧化应激效应，线粒体是LDH诱导产生活性氧的主要部位。扫描电子显微镜观察表明，两种LDHs均对藻类细胞表面造成严重损伤。在环境相关浓度下，LDHs主要以相加方式与两种共存污染物（土霉素和纳米二氧化钛）对斜生栅藻表现出联合毒性作用。这些发现强调了LDHs的内在性质、LDHs在水中的稳定性以及其他环境污染物对其生态毒理学效应的影响。
