A utilização de bioindicadores para avaliar o potencial mutagênico e citotóxico das águas do Rio Pirapó, região norte do Paraná, Brasil

Abstract

Water is a fundamental element factor to life and, its multiple utilities are, nowadays, indispensable to human activities. The discharge of pollutants from industrial, domestic and agricultural source is negatively affecting the aquatic biodiversity. In this way, studies are necessary to environmental monitoring, notably those using biologic measures, as bioindicators and biomarkers. This study aimed to evaluate the cytotoxic and mutagenic effects of Pirapó River waters, northern Paraná, through environmental bioindicators and biomarkers. Pirapó River is one of the principal water bodies of Paraná northern, and it is used by Apucarana and Maringá cities (third biggest city of Paraná State) for water public supplies and urban wastewater disposal (Sewage Treatment Station - STS). In this river, three sampled site were chosen: 1 – upstream site: in river springs, Apucarana; 2 – midstream: in Maringá, after the water caption and industrial wastewater release; 3 – downstream: in Maringá, after the release of STS. Individuals of fish Hypostomus ancistroides were sampled to assess the micronucleus formation and nuclear morphological alteration rates in summer and winter 2013. Abiotic data were recorded during the water sample to perform mutagenicity teste with Allium cepa bioassay in summer 2014. The nuclear abnormalities data of H. ancistroides were statistically tested with Kruskal-Wallis test followed by Mann Whitney with Bonferroni correction. To A. cepa was performed only a qualitative evaluation of genetic damages. The fishes of midstream site presented the highest values of nuclear morphological alterations and micronucleus, in both seasons. The punctual abiotic data associated with qualitative analysis of A. cepa bioassay corroborate the outcomes of fishes from midstream. In conclusion, our results indicate that the midstream site is under influence of pollutants, probably related to discharge of wastewater form industrial or agricultural activities developed surround this site. Knowing that Pirapó River supplies Maringá and nearby cities, our outcomes reveal data of preoccupant potential contamination into this water body, which can become it useless to public supply.