Photocatalytic reactive oxygen species production and phototoxicity of titanium dioxide nanoparticles are dependent on the solar ultraviolet radiation spectrum.
- Resource Type
- Article
- Authors
- Ma, Hongbo; Brennan, Amanda; Diamond, Stephen A.
- Source
- Environmental Toxicology & Chemistry. Sep2012, Vol. 31 Issue 9, p2099-2107. 9p.
- Subject
- *REACTIVE oxygen species
*TITANIUM dioxide
*NANOPARTICLES
*DAPHNIA magna
*LIGHT filters
*ULTRAVIOLET spectra
- Language
- ISSN
- 0730-7268
Generation of reactive oxygen species (ROS) by titanium dioxide nanoparticles (nano-TiO2) 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-TiO2, 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-TiO2. 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-TiO2 phototoxicity on environmentally realistic variations in solar radiation suggests that risk assessment of these nanomaterials requires careful evaluation of exposure conditions in the environment. Environ. Toxicol. Chem. 2012; 31: 2099-2107. © 2012 SETAC [ABSTRACT FROM AUTHOR]