Importance of chemical fractionation for the ecotoxicology of copper in the Dam Guarapiranga

• Grant number: 12/00307-6
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2012
• End date: June 30, 2015
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: José Roberto Machado Cunha da Silva
• Grantee: José Roberto Machado Cunha da Silva
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Breno Pannia Esposito ; Raúl Bonne Hernández

Abstract

Nowadays, water pollution is one of the most serious ecological problems, and domestic, industrial and agricultural wastes are the main sources of pollution in general and for metals. This study is being performed in order to assess the possible influence of the trophic state index and physicochemical variables in the fractionation of copper (Cu) as a determinant of the ecotoxicity of this metal in Guarapiranga Dam. Will be developed a fractionation scheme of copper in the aquatic system of the reservoir, to know the distribution of the metal and the possible environmental risks, it will determined the toxicity of the fractions as well as potential biomarkers and mechanisms of toxicity of Cu in the Zebra Fish (Danio rerio) depending on their bioavailability in the different fractions of water. We will make the determination of oxidative stress markers such as superoxide dismutase (SOD), catalase (CAT), cytochrome c oxidase (COX) e glutathione peroxidase (GPx) in gills and liver. We also will determine the copper bioaccumulation in gills and will make real-time PCR of some genes of enzymes such as CAT and SOD. The methods used include light microscopy, transmission electron microscopy and atomic absorption spectrometry. The project submitted will help to deepen the role of the fractionation of metals, specifically copper, in Guarapiranga Dam, establishing correlations with the toxic potential of the fractions in this reservoir which supplies water to a significant portion of the metropolitan region of São Paulo. (AU)