Concentração de metais pesados em peixes teleósteos do rio Piracicaba, Minas Gerais, Brasil

• Ano de defesa: 2009
• Autor(a) principal: Morais, Ana Carolina Torre
• Orientador(a): Matta, Sérgio Luis Pinto da
• Banca de defesa: Rocha, Juliana Silva , Freitas, Mariella Bomtempo Duca de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Biologia Animal
• Departamento: Biologia e Manejo animal
• País: BR
• Palavras-chave em Português: Histopatologias; Fígado; Brânquias; Testículo; Toxicologia
• Palavras-chave em Inglês: Histopathology; Liver; Gills; Testicle; Toxicology
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/2224

Heavy metals occur naturally in the environment, however anthropogenic activities can cause an increase of metals in the ecosystems, threatening the health of aquatic and terrestrial organisms, including men. Thus, the aim of this study was to determine the contamination by heavy metal of teleost fish from Piracicaba River (MG) and its effects on biomonitoring, aiming to provide a tool for measuring environmental quality. Specimens were collected in two locations of Piracicaba River, placed in Timóteo city, Minas Gerais state, Brazil. Sixty-three specimens were collected in three different collection days, 40 specimens were collected in location 1 and the remainder in location 2. Specimens were euthanized, and muscle, gills, liver, gonads were collected. Concentration of heavy metals was assessed in all tissues collected from all species. However, histopathological analyses were performed only in gills, liver and testes from two species: Astyanax bimaculatus and Geophagus brasiliensis. The concentration of aluminum (Al) (259,15 μg g-1 DW) in muscle fragments was the highest, followed by lead (Pb) (141,49 μg g-1 DW), zinc (Zn) (50,41 μg g-1 DW) and manganese (Mn) (14,91 μg g-1 DW). Of note, the concentrations of Pb and Zn detected in the muscle of the fish collected exceeded the safe limits established by the Health Ministry of Brazil. Regarding the season of the year, the concentration of metals in muscle was the highest during winter (174, 87 μg g-1 DW), followed by autumn (145, 07 μg g-1 DW) and then summer (29, 53 μg g-1 DW). The species G. brasiliensis presented more histopathological alterations, compared to A. bimaculatus, even though the latter presented larger concentration of metals. The metal Pb was the highest concentrated in both species. The higher histopathological response of G. brasiliensis permits us to suggest this species as a suitable indicator of environmental quality of the Piracicaba River. The values for hepatosomatic index of these two species were higher for the specimens from the river compared to the controls, and this may have occurred in response to the contamination of the river. The testes of these two species collected in the river presented higher concentration of metals, compared to controls. Of note, Pb was the highest concentrated metal in the testes of both species. The gonadosomatic index (IGS) of the two species from the control group was higher than the IGS of the specimens collected in the river, and these smaller values can be correlated to the higher concentration of metals in this group, what may be impairing the spermatogenic process. In conclusion, the fish specimens from the Piracicaba River presented the concentration of all metals in their muscle; some values were above the safe limits established by the Health Ministry, what represents a risk to people who ingest this fish. The histopathological alterations detected in the analyzed tissues permits us to infer that the environment is contaminated and that the alterations were produced in response to direct exposure to this environment, leading to the impairment of health and reproductive processes of fish that inhabit it.