Titanium dioxide nanoparticles (nTiO₂) have raised environmental concerns and display potential hazards to aquatic organisms and even humans. However, only a few reports tested the toxicity of nTiO₂ to rotifers. In the present study, acute and chronic toxicity of nTiO₂ to the freshwater rotifer Brachionus calyciflorus was investigated at different temperatures. At 25°C, the 24 and 48‐hr LC₅₀ was 117.14 and 60.11 mg/L, respectively. At 15°C, 20°C, 25°C, and 30°C, exposure to nTiO₂ significantly decreased life expectancy at birth, net reproductive rate, generation time, average lifespan, and/or intrinsic rate of population increase of B. calyciflorus (p < .05). High temperature enhanced the toxicity of nTiO₂ to rotifers. The swimming linear speed of rotifers significantly increased (p < .05) in treatments with 200 µg/L nTiO₂, compared with the control. In addition, treatments with 8 µg/L to 5 mg/L nTiO₂ significantly increased superoxide dismutase activity (p < .05). Glutathione content and catalase activity increased significantly after exposure to 8 µg/L nTiO₂ but decreased significantly in treatments with nTiO₂ concentrations ranging from 40 µg/L to 5 mg/L (p < .05). There were no significant changes in malondialdehyde contents among nTiO₂ treatments and control. Overall, the present study indicated that nTiO₂ revealed high toxicity to rotifers, displaying high environmental risks to aquatic ecosystems.

中文翻译：

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TiO2纳米粒子对淡水轮虫Brachionus calyciflorus的生命周期参数，抗氧化剂指数和游泳速度的影响。

二氧化钛纳米颗粒（nTiO ₂）引起了环境问题，并显示出对水生生物甚至人类的潜在危害。但是，只有少数报道测试了nTiO ₂对轮虫的毒性。在本研究中，研究了不同温度下nTiO ₂对淡水轮虫花椰菜Brachionus calyciflorus的急性和慢性毒性。在25°C下，24和48小时LC _50分别为117.14和60.11 mg / L。在15°C，20°C，25°C和30°C下，暴露于nTiO _2会显着降低出生时的预期寿命，净生殖率，生育时间，平均寿命和/或B人口的内在增长率。花萼（p  <.05）。高温增强了nTiO ₂对轮虫的毒性。与对照组相比， 用200 µg / L nTiO ₂处理时，轮虫的游泳线速度显着提高（p <.05）。此外，用8 µg / L到5 mg / L的nTiO _2处理可显着提高超氧化物歧化酶的活性（p  <.05）。暴露于8 µg / L nTiO ₂后，谷胱甘肽含量和过氧化氢酶活性显着增加， 但在浓度范围为40 µg / L至5 mg / L的nTiO ₂处理中，谷胱甘肽含量和过氧化氢酶活性显着下降（p  <.05）。nTiO ₂中丙二醛含量无明显变化治疗和控制。总体而言，本研究表明，nTiO ₂对轮虫具有高毒性，对水生生态系统具有高环境风险。