Utilização de biomarcadores genéticos para a avaliação do principal rio de abastecimento público da cidade de Dois Vizinhos, Paraná

Abstract

The water bodies are among the environments most affected by the disorderly growth of the human population. Considering the great importance of rivers and lakes, both for the resident organisms and for the health of the human population, strategies are needed that include, simultaneously, productivity and sustainability in the same environment, aiming at ecological balance. The objective of this work was to evaluate different types of pollution along the Jirau Alto River, in the municipality of Dois Vizinhos, PR, by means of genetic biomarkers in fish of the species Astyanax bifasciatus, in two seasons of the year (summer and winter). The Nuclear Morphological Changes (ENA) test associated with the micronucleus test and the Comet Assay in blood and liver were used as genetic biomarkers. The collections were carried out in two seasons (summer and winter of 2016) at four sampling points at the Jirau Alto river, and one control point at an APP. The biomarkers employed were the comet assay with erythrocytes and hepatocytes, and frequency of nuclear morphological changes (ENA). The micronucleus test was used to determine irreversible chromosome breaks in fish erythrocytes as well as nuclear morphological changes of various types. The comet assay is a very efficient technique in studies of toxic agents that cause damage to the genetic material, and in turn allows quantification of DNA breaks. The results obtained showed evidence of contamination in this river, the data obtained by the micronucleus test showed high damages, in all the sampling points when compared to the control point, in both stations. In the comet test, damage values were higher, especially in the summer and showing more significance especially at point P2. However, this response was non-linear, evidencing variations also between points and seasons. Thus, monitoring research becomes indispensable for the evaluation of the effects of environmental pollution and it is necessary to raise awareness of the population due to the threat of contamination in this river, since it plays an important role in the public supply of the city of Dois Vizinhos.