Eight years after the tailings dam collapse in Mariana, MG, Brazil, several aspects of this massive disaster are yet to be elucidated. Our goal was to investigate the impact of the mud flow on 16 fish species collected across 15 points from the Doce River, addressing 12 metal concentrations, tissue oxidative status (antioxidant enzymes and stress biomarkers), and histopathological analyses. The species Trachelyopterus striatulus, Prochilodus vimboides, Loricariichthys castaneus, Lophiosilurus alexandri, Hypostomus affinis, Hoplias intermedius were shown to be the most affected regarding the gills tissue integrity; Hypostomus affinis, Oligosarcus acutirostris, Lophiosilurus alexandri, Pygocentrus nattereri, Hoplosternum littorale, and Loricariichthys castaneus showed the highest levels of liver health. Overall, H. affinis was the most affected species, showing high levels of oxidative and histopathological damage, associated with high arsenic (As) and mercury (Hg) concentrations. In fish sampled from impacted regions, As and Hg exhibited higher concentrations compared to fish from unaffected sites, surpassing all the other analyzed metals. These high metal concentrations might be associated to the tailings dam failure, and As and Hg concentrations were positively correlated with alterations in oxidative stress biomarkers and histopathologies. Our results may be used as baseline for monitoring the environmental challenges that the Doce River fish species are facing at the moment.

中文翻译：

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Fundao 大坝坍塌后巴西多斯河鱼类物种的金属浓度、氧化状况和组织病理学评价


在巴西 MG 马里亚纳尾矿坝坍塌八年后，这场巨大灾难的几个方面仍有待阐明。我们的目标是调查泥流对从 Doce 河的 15 个点收集的 16 种鱼类的影响，解决 12 种金属浓度、组织氧化状态（抗氧化酶和应激生物标志物）和组织病理学分析。Trachelyopterus striatulus、Prochilodus vimboides、Loricariichthys castaneus、Lophiosilurus alexandri、Hypostomus affinis、Hoplias intermedius 被证明对鳃组织完整性的影响最大;Hypostomus affinis、Oligosarcus acutirostris、Lophiosilurus alexandri、Pygocentrus nattereri、Hoplosternum littorale 和 Loricariichthys castaneus 显示出最高水平的肝脏健康。总体而言，H. affinis 是受影响最严重的物种，表现出高水平的氧化和组织病理学损伤，与高砷 （As） 和汞 （Hg） 浓度有关。在受影响地区取样的鱼类中，与来自未受影响地区的鱼类相比，砷和汞的浓度更高，超过了所有其他分析的金属。这些高金属浓度可能与尾矿坝溃坝有关，并且 As 和 Hg 浓度与氧化应激生物标志物和组织病理学的改变呈正相关。我们的结果可以用作监测多斯河鱼类目前面临的环境挑战的基线。