Laboratory of Cellular Ultrastructure and Immunohistochemistry, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil.
Laboratory of Cellular Ultrastructure and Immunohistochemistry, Institute of Biological Sciences, Federal University of Pará (UFPA), Belém, Pará, Brazil.
Chemosphere. 2022 Jan;287(Pt 3):132263. doi: 10.1016/j.chemosphere.2021.132263. Epub 2021 Sep 16.
Tapajós Region, is an area with intense historical artisanal and small-scale gold mining. Therefore, the core objective of this study was to evaluate the environmental status of different rivers located in this region, using biomarker endpoints in Serrasalmus rhombeus as a tool. Fish and sediment were collected from two rivers, Tropas and Crepori, affluent of Tapajós River, located inside a Federal Protection Area and in a Reference site. Mercury concentration in sediment and fish were traced, and biomarkers in gills and liver were analyzed. Results showed a clear difference between these two rivers compared to the Reference site. Fish tissues presented biomarker responses according to the site of collection. Catalase (CAT) activity was statistically higher in fish gills from Crepori, confirming the capacity of mercury interference with redox equilibrium. High levels of lipid peroxidation were also noted to contribute greatly in incidence of morphological changes in the liver and gills, suggesting that mercury bioaccumulation during continuous exposure promote biological responses in a cumulative manner, from molecules to tissues. This study also indicates adaptation in fish defense mechanisms given the conditions in the Tropas River, as well as a variation in biomarker responses to that of the Crepori river. In summary, Tapajós affluents presented high mercury levels in fish tissues leading to biomarker responses, demonstrating a hazardous signal of a long history of mercury pollution.
塔帕若斯地区是一个历史上有密集的手工和小规模采金活动的地区。因此，本研究的核心目标是评估该地区不同河流的环境状况，使用罗贝氏臀点脂鲤作为工具的生物标志物终点。从塔帕若斯河的支流特罗帕斯河和克里波里河采集了鱼类和沉积物，这两条河流都位于一个联邦保护区内和一个参考点。追踪了沉积物和鱼类中的汞浓度，并分析了鳃和肝脏中的生物标志物。结果表明，与参考点相比，这两条河流有明显的差异。根据采集地点，鱼类组织表现出生物标志物反应。克里波里河的鱼鳃中的过氧化氢酶（CAT）活性明显更高，证实了汞干扰氧化还原平衡的能力。还注意到高水平的脂质过氧化，这极大地促成了肝脏和鳃中形态变化的发生，表明在连续暴露过程中，汞的生物积累以累积的方式促进了从分子到组织的生物反应。本研究还表明，鉴于特罗帕斯河的条件，鱼类的防御机制已经适应，克里波里河的生物标志物反应也有所变化。总之，塔帕若斯的支流中鱼类组织中的汞含量很高，导致生物标志物反应，这表明长期的汞污染存在危险信号。
