Monitoramento biológico de recursos hídricos na região do Triângulo Mineiro-MG, por meio do teste de micronúcleo e SMART

Abstract

Exposure to pollutants can induces a series of alterations in DNA that can cause genotoxic/mutagenic effects in the exposed individuals. It is the responsibility of the National Council for the Environment, under resolution 357/2005, to regulate the limits of chemical compounds permitted in surface waters. The present study aimed to monitor the genotoxic, mutagenic and recombinogenic potential and consequently the water quality, in two streams in the Paranaíba River basin (Minas Triangle region) and evaluate the genotoxic potential and consequent quality of the water from the Mumbuca stream, which supplies the city of Monte Carmelo in Minas Gerais state, Brazil, using two bioindicator fish with variable responses (Rhamdia quelen and Geophagus brasiliensis). Within the sites assessed, the Córrego do Óleo presented intermediate water quality, with a significant increase in micronucleus frequency compared to the reference site and similar to the Córrego Liso that showed a high toxic potential, with the presence of cadmium and lead, that resulted in high micronucleus rates that were similar to the positive control. At the sites assessed in the effluents in the Paranaíba River basin, there was inducement to somatic mutation and recombination in the wings of Drosophila melanogaster, indicating a possible presence of potentially toxic compounds. Data suggest that discharge of industrial effluents in specific stretch of the stream interfered with biota.