Data/hora: 22/09/2024 21:42:22

Biblioteca(s): 	Embrapa Meio Ambiente.	
Data corrente: 	31/10/2014	
Data da última atualização: 	31/10/2014	
Autoria: 	CLEMENTE, Z.; CASTRO, V. L. S. S. de; MOURA, M. A. M.; JONSSON, C. M.; FRACETO, L. F.	
Afiliação: 	ZAIRA CLEMENTE, IB-UNICAMP; VERA LUCIA SCHERHOLZ S DE CASTRO, CNPMA; MONICA ACAUI MARCONDES DE MOURA, IB-APTA; CLAUDIO MARTIN JONSSON, CNPMA; LEONARDO FERNANDES FRACETO, UNESP.	
Título: 	Toxicity assessment of TiO2 nanoparticles in zebrafish embryos underdifferent exposure conditions.	
Ano de publicação: 	2014	
Fonte/Imprenta: 	Aquatic Toxicology, Amsterdam, v. 147, p. 129-139, 2014.	
Idioma: 	Inglês	
Conteúdo: 	Abstract: The popularity of TiO2 nanoparticles (nano-TiO2) lies in their wide range of nanotechnological applications, together with low toxicity. Meanwhile, recent studies have shown that the photocatalytic properties of this material can result in alterations in their behavior in the environment, causing effects that have not yet been fully elucidated. The objective of this study was to evaluate the toxicity of two formulations of nano-TiO2 under different illumination conditions, using an experimental model coherent with the principle of the three Rs of alternative animal experimentation (reduction, refinement, and replacement). Embryos of the fish Danio rerio were exposed for 96 h to different concentrations of nano-TiO2 in the form of anatase (TA) or an anatase/rutile mixture (TM), under either visible light or a combination of visible and ultraviolet light (UV). The acute toxicity and sublethal parameters evaluated included survival rates, malformation, hatching, equilibrium, and overall length of the larvae, together with biochemical biomarkers (specific activities of catalase (CAT), glutathione S-transferase (GST), and acid phosphatase (AP)). Both TA and TM caused accelerated hatching of the larvae. Under UV irradiation, there was greater mortality of the larvae of the groups exposed to TM, compared to those exposed to TA. Exposure to TM under UV irradiation altered the equilibrium of the larvae. Alterations in the activities of CAT and GST were indicative of oxidative stress, although no clear dose-response relationship was observed. The effects of nano-TiO2 appeared to depend on both the type of formulation and the illumination condition. The findings contribute to elucidation of the factors involved in the toxicity of these nanoparticles, as well as to the establishment of protocols for risk assessments of nanotechnology.	
Palavras-Chave: 	Biomarker; Dióxido de titânio; FET; Fish Embryo Test; Nanoecotoxicologia; Nanotoxicology.	
Thesagro: 	Peixe de água doce; Raio ultravioleta; Toxidez.	
Thesaurus Nal: 	Danio rerio; Ecotoxicology; Nanoparticles; Nanotechnology; oxidative stress; Toxicity; Ultraviolet radiation.	
Categoria do assunto: 	H Saúde e Patologia	
Registro original: 	Embrapa Meio Ambiente (CNPMA)	
Exemplares: 	CNPMA - (13211-1) - UPC - AP - DD -  -  -  - DIS