Efeitos de diferentes usos e ocupações do solo em unidade de conservação na genotoxicidade de anfíbios

Abstract

The Campos de Palmas Wildlife Refuge (RVS-CP) is composed by natural fields and remnants of Araucaria Forest. The rural physiognomy of the region over the years has suffered ruptures driven by agriculture and forestry, especially those incorporated within the RVS-CP. Destruction of natural landscapes and intensive use of agrochemicals converge to environmental changes and exposure to xenobiotic pollutants. Thus, the present study aimed to investigate genotoxicity, using the micronucleus test (MN), for the species Physalaemus cuvieri, Dendropsophus minutus and Leptodactylus luctator, collected in the RVS-CP region, in areas of native grassland (CN1 and CN2), forestry (SIL1 and SIL2) and agriculture (AGRI1 and AGRI2), as well as evaluating the physicochemical characteristics of the water and sediment of the lakes. The results of the chemical parameters of the water reveal adequate values for hydrogenic potential (pH), temperature (T°C), total dissolved solids (TDS) and conductivity (SI), while oxidation-reduction potential (ORP), dissolved oxygen (%OD), turbidity (TNU), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) have fluctuated values between the collection dates and the sampled locations. The occurrence of agrochemicals in the sediment was recorded exclusively in AGR1, with the identification of 8 different active principles, among which the insecticide Imidacloprid had the highest concentration. Among the evaluated species and sampled environments, no significant frequencies of MN and erythrocyte abnormality collected in an agricultural environment, silviculture in relation to the preserved area, but when the average frequencies of MN and nuclear alterations were generated by the evaluated environment, a significant increase was recorded in the silviculture area associated with the BOD, DQO, NTU and ORP parameters. Principal component analysis (PCA) in analogy revealed that there is a positive correlation between the frequencies of nuclear alterations with ORP, NTU and agrochemicals. In this context, the absence or low frequency of micronuclei and other nuclear changes demonstrate that in situ studies suffer interference from the dynamics of the environment and are subject to anthropogenic and natural stressors that directly influence the biological action of organisms.