RESUMO
The aim of this research was to assess water quality in a stretch of the Paraguay River within the Brazilian Pantanal by means of a micronucleus assay with fish, and by water and sediment physicochemical analysis. Significant increases (p >0.05) in the frequency of micronuclei (MN) and micronucleated cells (MNC) occurred in erythrocytes of Pimelodus maculatus and Leporinus friderici at two river sites in the town of Caceres relative to an upstream reference site. The results demonstrate that the Paraguay River water near Caceres has been receiving genotoxic effluents, which may be associated with the presence of chromium, sulfides, oil and grease, and/or other chemicals.
Assuntos
Peixes-Gato/genética , Rios/química , Poluentes Químicos da Água/toxicidade , Qualidade da Água , Análise de Variância , Animais , Brasil , Caraciformes , Eritrócitos/efeitos dos fármacos , Testes para Micronúcleos , Estações do Ano , Especificidade da EspécieRESUMO
The genotoxic activity of surface water samples from four sites along the Paraguay River, near Cáceres, Mato Grosso State, Brazil, was investigated using the Drosophila melanogaster Somatic Mutation and Recombination test (SMART). Effluents from sanitary sewers and agroindustrial effluents (residual effluents from slaughterhouses, leather tanneries, and dairies) flow into the Paraguay River, and directly or indirectly contaminate water from sampling sites 1-3. Site 4 was an upriver reference site that received no domestic or agroindustrial discharges. Water was collected at 4 time periods: September 2003 and August 2004 (periods of low water or drought); and April 2004 and March 2005 (periods of high water or flood). Chromium concentrations above statutory limits were detected at sites 1-3 (August 2004), and sites 1, 2 and 4 (March 2005). Sulfur compounds were also detected at sites 1-3. The SMART performed using standard (ST) cross flies detected genotoxic responses in only two samples, the August 2004 site 1 sample and the March 2005 site 2 sample. Many more samples were positive using high bioactivation (HB) cross flies: site 1 (all collection periods), site 2 (September 2003 and April 2004), and site 3 (September 2003 and August 2004). Mutant frequency comparisons between marker-heterozygous and balancer-heterozygous flies from the HB cross indicated that the positive genotoxic responses for the site 2 (April 2004) and site 3 (September 2003) samples were due mainly to mitotic recombination. Our findings indicate that the section of the Paraguay River within the urban perimeter of Cáceres is contaminated with genotoxic agents.
Assuntos
Rios/química , Poluentes Químicos da Água/toxicidade , Asas de Animais/efeitos dos fármacos , Animais , Brasil , Drosophila melanogaster , Monitoramento Ambiental/métodos , Feminino , Genes de Insetos/genética , Geografia , Larva/efeitos dos fármacos , Larva/genética , Masculino , Testes de Mutagenicidade/métodos , Estações do Ano , Asas de Animais/anormalidades , Asas de Animais/metabolismoRESUMO
Plantago major is used in many parts of the world for the treatment of diseases and to promote the healing of wounds. In the present study, the somatic mutation and recombination test (SMART) in Drosophila melanogaster was used to evaluate the genotoxic activity of an aqueous extract of P. major. The following Drosophila crosses were made: standard (ST) cross, in which virgin flare females (flr3/TM3, Bds) were mated with mwh/mwh males, and high-bioactivation (HB) cross, in which virgin ORR females (ORR/ORR; flr3/TM3, Bds) were mated with mwh/mwh males. Each cross produced two types of descendents, marker-transheterozygous (MH) (mwh +/+ flr3) and balancer-heterozygous (BH) (mwh +/+ TM3, Bds) flies. Three-day-old larvae of both types of descendents were treated with undiluted and diluted (1:1 and 1:2 in water) aqueous extracts of P. major. The extracts were genotoxic in both crosses, producing similar induced frequencies in ST and HB flies. Comparison of the frequencies of wing spots in the BH and MH descendents indicated that recombination was a major response. The results indicate that, under these experimental conditions, aqueous extracts of P. major are genotoxic (recombinagenic).