Toxicity of Titanium Dioxide Nanoparticles to Tadpoles of Asian Common Toad (Duttaphrynus melanostictus) Following Short Term and Chronic Exposures

Abstract

Nanotoxicity data for amphibians are limited compared to other taxonomic groups. The present study assessed toxicity of titanium dioxide nanoparticles ( nanoTiO2, anatase form, particle size < 25 nm) on tadpoles of Duttaphrynus melanostictus after short term and chronic exposures. Exposure to nanoTiO2 (≤ 100 mg/L) for 96 h had no significant effect on survival but upon transfer to nanoTiO2 free water for another 21 days, survival of the tadpoles pre-exposed to nanoTiO2 was greatly reduced and their development was delayed. Chronic exposure to nanoTiO2 (0.1 to 10 mg/L) for 14 days had no significant effects on acetylcholinesterase activities but induced mortalities (up to 40%) and histological alterations in the intestine and liver tissues. The results indicate that release of nanoTiO2 to aquatic ecosystems could pose negative impacts to amphibian populations.