title: Toxicity Assessment of Titanium (IV) Oxide Nanoparticles Using Daphnia magna (Water Flea).
abstract: OBJECTIVE
  Titanium dioxide (TiO(2)), a common nanoparticle widely used in industrial production, is one of nano-sized materials. The purpose of this study was to determine the acute and chronic toxicity of TiO(2) using different size and various concentrations on Daphnia magna.
  
  
  METHODS
  In the acute toxicity test, four concentrations (0, 0.5, 4, and 8 mM) for TiO(2) with 250 or 500 nm and five concentrations (0, 0.25, 0.5, 0.75, and 1 mM) for TiO(2) with 21 nm were selected to analyze the toxic effect to three groups of ten daphnia neonates over 96 hours. In addition, to better understand their toxicity, chronic toxicity was examined over 21 days using 0, 1, and 10 mM for each type of TiO(2).
  
  
  RESULTS
  Our results showed that all organisms died before the reproduction time at a concentration of 10 mM of TiO(2). In addition, the exposure of anatase (21 nm) particles were more toxic to D. magna, comparing with that of anatase (250 nm) and rutile (500 nm) particles.
  
  
  CONCLUSIONS
  This study indicated that TiO(2) had adverse impacts on the survival, growth and reproduction of D. magna after the 21days exposure. In addition, the number of test organisms that were able to reproduce neonates gradually were reduced as the size of TiO(2) tested was decreased.
authors: Department of Bioprocess Engineering, Chonbuk National University, Jeonju, Korea.
authors: Seung Hyuck
authors: SH
authors: Bang
authors: Thai-Hoang
authors: TH
authors: Le
authors: Sung Kyu
authors: SK
authors: Lee
authors: Pil
authors: P
authors: Kim
authors: Jong Soo
authors: JS
authors: Kim
authors: Jiho
authors: J
authors: Min