Aquatic Contaminants Research Division, Environment and Climate Change Canada, 105 McGill, Montréal, Québec H2Y 2E7, Canada.
Aquatic Contaminants Research Division, Environment and Climate Change Canada, 105 McGill, Montréal, Québec H2Y 2E7, Canada.
Comp Biochem Physiol C Toxicol Pharmacol. 2019 May;219:1-11. doi: 10.1016/j.cbpc.2019.01.005. Epub 2019 Jan 25.
The release of engineered nanoparticles in the aquatic environment could pose a threat to the biota. The purpose of the study was to examine the influence of surface water characteristics on zinc oxide nanoparticles (nZnO) and ZnS0 toxicity to the freshwater mussel Dreissena polymorpha. Mussels were exposed to an equivalent concentration of 25 μg/L Zn as either nZnO or ZnSO for 96 h at 15 °C in 4 types of surface waters: green water (high conductivity and pH with low natural organic matter content), brown water (low conductivity and pH with high natural organic matter content), diluted municipal effluent (high conductivity and pH with high urban organic matter content) and aquarium water (treated green water with organic matter removed). After the exposure period, mussels were analyzed for air-time survival, total and labile Zn levels in tissues, lipid metabolism (phospholipase A2, triglycerides levels) and oxidative stress (glutathione S-transferase, arachidonate cyclooxygenase, lipid peroxidation). The data revealed that mussels exposed to ZnSO in controlled aquarium water accumulated more total and labile Zn tissues, decreased oxidative stress and triglycerides and increased air time survival. While nZnO had few effects in aquarium water, oxidative stress was enhanced and total Zn in tissues were decreased in brown water and diluted municipal effluent and triglycerides were higher in nZn-exposed mussels in brown water. Air-time survival was decreased in mussels kept in green water and nZnO. It was also decreased in mussels exposed to ZnSO in green water and diluted municipal effluent. In conclusion, the fate and toxic effects of Zn could be influenced by both the chemical form (nanoparticles or ionic Zn) and surface water properties in freshwater mussels.
在水生环境中释放工程纳米颗粒可能会对生物区系构成威胁。本研究的目的是研究地表水特性对氧化锌纳米颗粒（nZnO）和 ZnS0 对淡水贻贝多形蜉蝣毒性的影响。在 15°C 下，将贻贝分别暴露于相当于 25μg/L Zn 的 nZnO 或 ZnSO4 中 96 h，在 4 种地表水类型中：绿水（高电导率和 pH 值，低天然有机物含量）、褐水（低电导率和 pH 值，高天然有机物含量）、稀释的市政污水（高电导率和 pH 值，高城市有机物含量）和水族馆水（经过处理的绿水，去除有机物）。暴露期结束后，分析贻贝的空气暴露存活时间、组织中的总锌和可利用锌水平、脂质代谢（磷脂酶 A2、甘油三酯水平）和氧化应激（谷胱甘肽 S-转移酶、花生四烯酸环氧化酶、脂质过氧化）。数据显示，在受控水族馆水中暴露于 ZnSO4 的贻贝组织中总锌和可利用锌的积累量增加，氧化应激和甘油三酯减少，空气暴露存活时间延长。而 nZnO 在水族馆水中的影响较小，但在褐水和稀释的市政污水中，氧化应激增强，组织中的总锌减少，褐水中 nZnO 暴露的贻贝中的甘油三酯含量较高。在绿水中和 nZnO 暴露的贻贝中，空气暴露存活时间减少。在绿水中和稀释的市政污水中暴露于 ZnSO4 的贻贝中，空气暴露存活时间也减少。综上所述，Zn 的归宿和毒性效应可能同时受到化学形态（纳米颗粒或离子 Zn）和淡水贻贝中地表水特性的影响。
