Office of Research and Development, Mid-Continent Ecology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Duluth, Minnesota, USA.
Environ Toxicol Chem. 2012 Sep;31(9):2099-107. doi: 10.1002/etc.1916. Epub 2012 Jul 22.
Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO(2)) and its consequent phototoxicity to Daphnia magna were measured under different solar ultraviolet (UV) spectra by applying a series of optical filters in a solar simulator. Removing UV-B (280-320 nm) from solar radiation had no significant impact on photocatalytic ROS production of nano-TiO(2), whereas removal of UV-A (320-400 nm) decreased ROS production remarkably. Removal of wavelengths below 400 nm resulted in negligible ROS production. A linear correlation between ROS production and D. magna immobilization suggests that photocatalytic ROS production may be a predictor of phototoxicity for nano-TiO(2). Intracellular ROS production within D. magna was consistent with the immobilization of the organism under different solar UV spectra, indicating that oxidative stress was involved in phototoxicity. The dependence of nano-TiO(2) phototoxicity on environmentally realistic variations in solar radiation suggests that risk assessment of these nanomaterials requires careful evaluation of exposure conditions in the environment.
通过在太阳模拟器中应用一系列光学滤光片，测量了二氧化钛纳米粒子（纳米-TiO(2)）产生的活性氧物种（ROS）及其对大型溞（Daphnia magna）的光毒性，在不同的太阳紫外线（UV）光谱下进行了测量。从太阳辐射中去除 UV-B（280-320nm）对纳米-TiO(2)的光催化 ROS 产生没有显著影响，而去除 UV-A（320-400nm）则显著降低了 ROS 的产生。去除波长低于 400nm 则导致 ROS 产生可忽略不计。ROS 产生与 D. magna 固定之间的线性相关性表明，光催化 ROS 产生可能是纳米-TiO(2)光毒性的预测指标。D. magna 内的细胞内 ROS 产生与生物体在不同太阳 UV 光谱下的固定一致，表明氧化应激参与了光毒性。纳米-TiO(2)光毒性对环境中太阳辐射的实际变化的依赖性表明，对这些纳米材料的风险评估需要仔细评估环境中的暴露条件。
