RESUMO
The present study aimed to report the morphometric and hematological indices and genotoxicity of a free-life population of D'Orbigny's slider turtles (Trachemys dorbigni) living in an urban area in Southern Brazil. For that, 16 specimens were randomly captured in an urban canal that receives irregular releases of wastewater. Biometrics and external visual changes were analyzed, such as turtle shell deformities, and the presence of parasites. Blood samples were collected to evaluate the hematological profile and the presence of micronuclei and other erythrocyte nuclear abnormalities as potential mutagenic and genotoxic effects. Water physicochemical parameters were also measured. Organisms with ectoparasites (31.25%) and small carapace deformations (56.25%) were observed, but maximum carapace length and weight were considered normal for the species according to the literature. The blood profile indicated low hemoglobin and hematocrit and a high number of total leukocytes, particularly eosinophils which characterize parasitic infections. A frequency of 0.12% for the micronucleus was considered basal, but the frequency of other erythrocyte abnormalities was evident, mainly of blebbed nuclei (63.79%), indicating chromosomal damage in the early stage. The results of this study suggest that natural populations of chelonian inhabiting urbanized areas are impacted by anthropogenic activities in the surrounding environment. Furthermore, it provides comprehensive data which can serve as a comparative model for environmental monitoring studies involving turtles.
Assuntos
Tartarugas , Animais , Brasil , Biomarcadores/sangue , Água Doce , Monitoramento Ambiental , Testes para MicronúcleosRESUMO
This study performed toxicity assays with microalgae, microcrustaceans, and fish as well as evaluated biochemical and behavioral biomarkers in fish and microcrustaceans to assess the quality of the surface water of Mirim Lagoon, which belongs to one of the largest hydrographic basins in the world, located in southern Brazil. Three distinct sampling periods were chosen (January, March, and June 2022) based on the rice plantation dynamics which is the main activity surrounding the lagoon. In January, the plantation is irrigated; in March, the water is drained into the Mirim Lagoon, and July is the off-season. Concerning toxicity tests, there was significant inhibition in microalgae growth when exposed to water collected in March, but no mortality was observed for Ceriodaphia dubia, Daphnia magna, and Danio rerio. Regarding biomarkers, behavioral variables contributed more to the higher values of the Integrated Biomarker Response (IBR) index for both D. magna and D. rerio, in March. The Redundancy Analysis (RDA) indicated a correlation between the biomarkers for both organisms and abiotic parameters, mainly nutrients (total phosphorus and total nitrogen), thermotolerant coliforms, total solids, and turbidity. Spatially, there was no difference during monitoring, but the most significant ecotoxicological effects were observed in March. Multivariate analysis and the IBR index proved to be useful tools for monitoring of water bodies such as Mirim Lagoon.
Assuntos
Monitoramento Ambiental , Microalgas , Animais , Brasil , Daphnia magna , Biomarcadores , ÁguaRESUMO
The objective of this research was to investigate the potential damage caused by the residual concentrations of the insecticides Regent® WS 800 and Curbix® SC 200, containing fipronil and ethiprole, respectively as active ingredients, on the liver of Oreochromis niloticus. The analyses of HSP70 shock protein labelling and cell death process by TUNEL method were performed in order to measure the effects of the exposure of cell repair system of fish to both insecticides. Statistical analyses showed no significant molecular damage to the hepatic tissue of animals. Nevertheless, variations in HSP70 and DNA fragmentation levels, endpoint of cell repair system response and cellular death, respectively, were observed in several groups. These results indicate that the cell repair machinery was efficient when in contact with residual concentrations of insecticides. However, the DNA fragmentation detected by the TUNEL method suggests that even in face of the cytoprotective action of the HSP70 protein, there are damages that become irreparable. To finish, it is worth mentioning that given the results obtained from residual concentrations, use in the field should be with caution.
Assuntos
Ciclídeos/fisiologia , Proteínas de Choque Térmico HSP70/metabolismo , Inseticidas/toxicidade , Pirazóis/toxicidade , Animais , Morte Celular/efeitos dos fármacos , Biomarcadores Ambientais/efeitos dos fármacos , Proteínas de Peixes/metabolismo , Fígado/efeitos dos fármacos , Resíduos de Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
Sugarcane vinasse is a residue generated at a rate fifteen times greater than the ethanol production. Because of its high organic and micronutrient content, this residue is used as a fertilizer on sugarcane crops. However, when used in large quantities, vinasse can saturate the soil and contaminate nearby water resources by percolation and leaching. Given the proven toxic potential of in natura vinasse, the present study aimed to evaluate the toxic potential of leached sugarcane vinasse using Nile tilapia (Oreochromis niloticus) as a test organism. A bioassay was performed after vinasse percolation in laboratory soil columns. The bioassay included one control group containing fresh water and two treatment groups, the first exposed to a 2,5% dilution of leached of vinasse and the second to a 2,5% dilution of in natura vinasse. After exposure, histopathological analysis was performed in gills and livers, and the latter were labelled for HSP70 proteins. No significant changes were detected in the gills of the exposed fish. However, in the liver, both in natura and leached vinasse induced statistically significant histopathological changes. These changes include hydropic degeneration, cell boundary losses, pyknotic nuclei and cellular disorganization. HSP70 expression significant increase in liver of both treatment groups were observed, being higher for the in natura vinasse exposed group. Results suggested that both leached vinasse and in natura vinasse were toxic, its still able to provoke histological changes and induce the cytoprotective response in exposed fish liver, evidenced by a immunostaining of cellular stress proteins. Thus, in order to reduce its environmental impact, appropriated effluent disposal is essential.
Assuntos
Ciclídeos , Misturas Complexas/toxicidade , Etanol/toxicidade , Brânquias/patologia , Proteínas de Choque Térmico HSP70/metabolismo , Fígado/patologia , Animais , Etanol/metabolismo , Fertilizantes/toxicidade , Brânquias/metabolismo , Fígado/metabolismo , Saccharum , Poluentes Químicos da Água/toxicidadeRESUMO
The use of pesticides has increased worldwide, owing to the demand for products of good quality and to satisfy a growing population. Herbicides represent almost half of the total amount of pesticides used. Although important to the reduction of costs and an increase of productivity, their indiscriminate use, as well as that of the other pesticides, is a global environmental problem, since they affect the living organisms. To evaluate the damage caused by herbicides to the environment, different organisms have been used as bioindicators, especially higher plants, due to several advantages. This is a literature review on herbicidal actions in plant bioindicators, as assessed by genetic biomarkers. Also, the present manuscript aimed to characterize the main organisms (Allium cepa, Vicia faba and Tradescantia spp.) and the most used biomarkers (mitotic index, chromosome aberrations, micronuclei, sister chromatid exchange and mutations). We concluded that herbicides induce cytotoxicity and genotoxicity in the assessed bioindicators. The data corroborate the existing warnings of the risks that the indiscriminate and increasing use of pesticides poses to the environment and its biodiversity.