Assessment of Crystal Morphology on Uptake, Particle Dissolution, and Toxicity of Nanoscale Titanium Dioxide on Artemia salina.

Abstract

Knowledge of nanomaterial toxicity is critical to avoid adverse effects on human and environment health. In this study, the influences of crystal morphology on physico-chemical and toxic properties of nanoscale TiO₂ (n-TiO₂) were investigated. Artemia salina were exposed to anatase, rutile and mixture polymorphs of n-TiO₂ in seawater. Short-term (24 h) and long-term (96 h) exposures were conducted in 1, 10 and 100 mg/L suspensions of n-TiO₂ in the presence and absence of food. Anatase form had highest accumulation followed by mixture and rutile. Presence of food greatly reduced accumulation. n-TiO₂ dissolution was not significant in seawater (p<0.05) nor was influenced from crystal structure. Highest toxic effects occurred in 96h exposure in the order of anatase > mixture > rutile. Mortality and oxidative stress levels increased with increasing n-TiO₂ concentration and exposure time (p<0.05). Presence of food in the exposure medium alleviated the oxidative stress, indicating that deprivation from food could promote toxic effects of n-TiO₂ under long-term exposure.