Marques Helen Gonçalves, Soares Larissa Batista, de Andrade Frank Pereira, de Campos José Marcello Salabert, Palmieri Marcel José, Brasileiro-Vidal Ana Christina, Bustamante Fernanda de Oliveira
Laboratório de Análises Genéticas, Departamento de Ciências Naturais e da Terra, Universidade do Estado de Minas Gerais, Divinópolis, MG 35501-170, Brazil; Universidade Federal de São João Del-Rey, UFSJ Unidade Divinópolis, Campus Centro-Oeste Dona Lindu, Divinópolis, MG 35501-296, Brazil.
Laboratório de Análises Genéticas, Departamento de Ciências Naturais e da Terra, Universidade do Estado de Minas Gerais, Divinópolis, MG 35501-170, Brazil.
Sci Total Environ. 2025 Feb 10;964:178618. doi: 10.1016/j.scitotenv.2025.178618. Epub 2025 Jan 24.
The rupture of Vale S.A. mining tailings dam in Brumadinho, Brazil, in January 2019 had significant environmental impacts on the Paraopeba River basin. Additionally, severe floods in early 2022 contributed to the transport of particles in the river. This study aimed to evaluate the cytotoxic and genotoxic potential of Paraopeba River water. Thus, the Allium cepa test system was applied, along with physicochemical analyses, flow cytometry, and metal concentration, comparing the results between the rainy and dry seasons three years after the dam rupture. The tests were conducted on water samples collected during three periods: January 2022, July 2022, and January 2023, at five points along the river and its tributaries. Allium cepa seeds were exposed to the collected water samples, as well as negative (water) and positive (trifluralin) controls. Cytotoxicity was evaluated using the mitotic index and flow cytometry, and genotoxicity by the chromosomal alterations index. The analysis of metals and physicochemical parameters revealed that most values complied with current regulations. However, there were exceptions, with ammonia levels exceeding the permitted limits at all points in the three collections. High levels of aluminum, iron and nitrite were found at most points, before and after the dam collapse, mainly during the rainy season. This indicates the impact of rainfall on water quality, which increases the transport of contaminating particles, probably resulting from human activities and the high concentration of nitrogen compounds released into the Paraopeba River. The results of the bioassay suggest a relatively low cytotoxic and genotoxic potential of the samples evaluated. However, this study highlights the continuous contamination of the river by unidentified anthropogenic factors, requiring continuous monitoring and analysis to track the evolution of water quality and its environmental effects.
2019年1月，巴西布鲁马迪纽的淡水河谷公司（Vale S.A.）采矿尾矿坝决堤，对帕拉奥佩巴河流域造成了重大环境影响。此外，2022年初的严重洪水致使河流中颗粒物迁移。本研究旨在评估帕拉奥佩巴河河水的细胞毒性和遗传毒性潜力。因此，应用了洋葱（Allium cepa）测试系统，并结合理化分析、流式细胞术和金属浓度检测，比较了大坝决堤三年后雨季和旱季的结果。测试针对2022年1月、2022年7月和2023年1月三个时间段沿河流及其支流五个地点采集的水样进行。将洋葱种子暴露于采集的水样以及阴性（水）和阳性（氟乐灵）对照中。使用有丝分裂指数和流式细胞术评估细胞毒性，通过染色体改变指数评估遗传毒性。金属和理化参数分析表明，大多数值符合现行规定。然而，也有例外情况，三次采样中所有地点的氨含量均超过许可限值。在大坝坍塌前后的大多数地点，主要在雨季，发现了高含量的铝、铁和亚硝酸盐。这表明降雨对水质有影响，降雨增加了污染颗粒的迁移，这可能源于人类活动以及排入帕拉奥佩巴河的高浓度含氮化合物。生物测定结果表明，所评估样品的细胞毒性和遗传毒性潜力相对较低。然而，本研究强调了河流受到不明人为因素的持续污染，需要持续监测和分析以追踪水质演变及其环境影响。
