title: The toxicity of titanium dioxide nanopowder to early life stages of the Japanese medaka (Oryzias latipes).
abstract: In this study, fertilized Japanese medaka (Oryzias latipes) embryos were exposed from fertilization to 5 d post-hatch using static non-renewal assays to aqueous suspensions of titanium dioxide nanoparticles (nTiO₂) ranging in nominal concentrations between 0 and 14 μg mL⁻¹. The average size of the nTiO₂ in the stock solution before addition to the test treatments was 87 nm (±14 nm). TiO₂ materials accumulated in a concentration dependent manner on the chorionic filaments of developing medaka embryos with evidence of pericardial edema occurring during embryo development. However, no significant (p > 0.05) increases in mortality relative to control treatments were observed for the nTiO₂ exposed embryos. A concentration dependent increase in cumulative percent hatch was observed at 11 d, indicating that exposure to increasing concentrations of nTiO₂ resulted in the premature hatch of medaka embryos. Post-hatch, a significant proportion of sac fry from the nTiO₂ exposure groups exhibited moribund swimming behavior and these individuals also experienced greater mortality at 15 d post-hatch. Combined, these results demonstrate that exposure to nTiO₂ can impact the development of early life stages of fish.
authors.affiliation: Worsfold Water Quality Centre, Trent University, Peterborough, Ontario, Canada. gpaters@uwindsor.ca
authors.forename: Gordon
authors.initials: G
authors.lastname: Paterson
authors.forename: Jamie M
authors.initials: JM
authors.lastname: Ataria
authors.forename: M Ehsanul
authors.initials: ME
authors.lastname: Hoque
authors.forename: Darcy C
authors.initials: DC
authors.lastname: Burns
authors.forename: Chris D
authors.initials: CD
authors.lastname: Metcalfe
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects; D047108:Embryonic Development / Q000187:drug effects; D007814:Larva / Q000187:drug effects; D053768:Metal Nanoparticles / Q000633:toxicity*; D009990:Oryzias / Q000002:abnormalities / Q000196:embryology* / Q000502:physiology; D011208:Powders; D014025:Titanium / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D011208:Powders; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium