title: Acute effects of Fe₂O₃, TiO₂, ZnO and CuO nanomaterials on Xenopus laevis.
abstract: Metal oxide nanomaterials have exhibited toxicity to a variety of aquatic organisms, especially microbes and invertebrates. To date, few studies have evaluated the toxicity of metal oxide nanomaterials on aquatic vertebrates. Therefore, this study examined effects of ZnO, TiO(2), Fe(2)O(3), and CuO nanomaterials (20-100 nm) on amphibians utilizing the Frog Embryo Teratogenesis Assay Xenopus (FETAX) protocol, a 96 h exposure with daily solution exchanges. Nanomaterials were dispersed in reconstituted moderately hard test medium. These exposures did not increase mortality in static renewal exposures containing up to 1,000 mg L(-1) for TiO(2), Fe(2)O(3), CuO, and ZnO, but did induce developmental abnormalities. Gastrointestinal, spinal, and other abnormalities were observed in CuO and ZnO nanomaterial exposures at concentrations as low as 3.16 mg L(-1) (ZnO). An EC(50) of 10.3 mg L(-1) ZnO was observed for total malformations. The minimum concentration to inhibit growth of tadpoles exposed to CuO or ZnO nanomaterials was 10 mg L(-1). The results indicate that select nanomaterials can negatively affect amphibians during development. Evaluation of nanomaterial exposure on vertebrate organisms are imperative to responsible production and introduction of nanomaterials in everyday products to ensure human and environmental safety.
authors.affiliation: Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, TX 79409, USA. shaylobo42@hotmail.com
authors.forename: Shawna
authors.initials: S
authors.lastname: Nations
authors.forename: Mike
authors.initials: M
authors.lastname: Wages
authors.forename: Jaclyn E
authors.initials: JE
authors.lastname: Cañas
authors.forename: Jonathan
authors.initials: J
authors.lastname: Maul
authors.forename: Chris
authors.initials: C
authors.lastname: Theodorakis
authors.forename: George P
authors.initials: GP
authors.lastname: Cobb
mesh_terms: D000818:Animals; D003300:Copper / Q000633:toxicity*; D019465:Craniofacial Abnormalities / Q000139:chemically induced; D004065:Digestive System Abnormalities / Q000139:chemically induced; D005290:Ferric Compounds / Q000633:toxicity*; D006801:Humans; D007814:Larva / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D049329:Nanostructures / Q000633:toxicity*; D038081:Organogenesis / Q000187:drug effects; D014025:Titanium / Q000633:toxicity*; D014982:Xenopus laevis / Q000254:growth & development*; D015034:Zinc Oxide / Q000633:toxicity*
chemical_list: D005290:Ferric Compounds; C009495:titanium dioxide; C000499:ferric oxide; D003300:Copper; D014025:Titanium; D015034:Zinc Oxide; C030973:cupric oxide