Avaliação in vivo e in vitro do potencial citogenotóxico de afluentes do Rio Uberabinha (Uberlândia-MG): uma ferramenta para o biomonitoramento da qualidade da água

Abstract

The water quality of several watercourses has been reduced due to the considerable increase of contaminants, mainly of anthropic origin, in the aquatic ecosystems. In this scenario, it is essential to biomonitoring the environmental quality of these sites to understand the problem and thus lead to the proposal of actions aimed at the proper management of these sites. The Uberabinha River is the main watercourse responsible for the supply of the city of Uberlândia-MG and several scientific works point to a growing degradation in this place. Considering this, the present study had as objective to perform the biomonitoring of water quality in some tributaries of this river, through cytotoxic tests in model organisms. The water collection was carried out in five tributaries: Córrego do Paula (C1), Ribeirão Bom Jardim (C2), Córrego Lagoinha (LA1 and LA2), Córrego do Óleo (OL1) and Córrego Liso (L1, L2 and L3) being also submitted to physical-chemical analysis and Water Quality Index (IQA) calculation. To evaluate the cytotoxic potential of the water from the tributaries, in vivo bioassays were performed using Allium cepa and Poecilia reticulata and in vitro with C2C12 cells. The results obtained in the analysis of the physical-chemical parameters presented many non-conformities, one of them was the presence of heavy metals Cadmium and Lead. The IQA classified the tributaries C1 and C2 as "GOOD" and the others as "BAD". For cytotoxicity the tests were: root size, Mitotic Index and cell viability. The water samples did not present cytotoxic effects, on the contrary, demonstrated cellular proliferation. For genotoxicity the tests were: micronucleus (MN), chromosomal aberrations and cellular abnormalities. Most of the tributaries presented a high genotoxic potential, with a statistically significant increase in the frequency of micronucleus of all bioassays. The changes in the physico-chemical parameters and the cytotoxotoxic effects observed may be correlated, and the consequence of these results may be due to the discards of domestic and industrial effluents in the places that, according to the water analysis, presented Cadmium and Lead, agents capable of causing damage to the genetic material.