Modeling TiO2 nanoparticle phototoxicity: The importance of chemical concentration, ultraviolet radiation intensity, and time. (October 2015)

• Record Type: Journal Article
• Authors: Li, Shibin; Erickson, Russell J.; Wallis, Lindsay K.; Diamond, Stephen A.; Hoff, Dale J.
• Is Part Of: Environmental pollution. Volume 205(2015)
• Page Start: 327
• Page End: 332
• Publication Date: 2015-10
• Subjects: Nano-TiO2 -- Phototoxicity -- Dosimetry model -- Hyalella azteca -- Bunsen-Roscoe photochemical law; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2015.06.020
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: As a semiconductor with wide band gap energy, TiO2 nanoparticles (nano-TiO2 ) are highly photoactive, and recent efforts have demonstrated phototoxicity of nano-TiO2 to aquatic organisms. However, a dosimetry model for the phototoxicity of nanomaterials that incorporates both direct UV and photo-activated chemical toxicity has not yet been developed. In this study, a set of Hyalella azteca acute toxicity bioassays at multiple light intensities and nano-TiO2 concentrations, and with multiple diel light cycles, was conducted to assess how existing phototoxicity models should be adapted to nano-TiO2 . These efforts demonstrated (a) adherence to the Bunsen-Roscoe law for the reciprocity of light intensity and time, (b) no evidence of damage repair during dark periods, (c) a lack of proportionality of effects to environmental nano-TiO2 concentrations, and (d) a need to consider the joint effects of nano-TiO2 phototoxicity and direct UV toxicity. Graphical abstract: Highlights: A predictive model for phototoxicity is developed. A lack of proportionality exists for dose response of nano-TiO2 phototoxicity. Joint effects exist of photo-activated nano-TiO2 toxicity and direct UV exposure. Abstract : A dosimetry model was developed to evaluate critical aspects of phototoxicity of nanomaterials.