Laboratory of Animal Health (LARSANA), Federal University of Western Pará (UFOPA), Rua Vera Paz, s/n, Salé, CEP 68040-255 Santarém, PA, Brazil; Department of Animal Pathology, Veterinary Faculty, Universidade de Santiago de Compostela, 27002 Lugo, Spain.
Laboratory of Animal Health (LARSANA), Federal University of Western Pará (UFOPA), Rua Vera Paz, s/n, Salé, CEP 68040-255 Santarém, PA, Brazil.
Sci Total Environ. 2020 Aug 25;732:138983. doi: 10.1016/j.scitotenv.2020.138983. Epub 2020 Apr 30.
The Lower Amazon region (Western Pará, northern Brazil) is greatly affected by mining exploitations (particularly artisanal gold mines) and other industrial and intensive agricultural activities with potentially strong impacts on aquatic ecosystems. Although such impacts include contamination with various toxic elements, to date only the effects of Hg have been considered. In this study, toxic and trace element concentrations were determined in the flesh of 351 fish specimens, including detritivores (Acarí, Pterygoplichthys pardalis), omnivores (Piranha, Pygocentrus nattereri; Pirarucu, Arapaima sp.) and carnivores (Caparari, Pseudoplatystoma fasciatum; Tucunaré, Cichla ocellaris), during the dry and wet seasons in 2015 and 2016. The range of concentrations of toxic element residues were 2-238 μg/kg fresh weight for As, 1-77 μg/kg for Cd, 4-1922 μg/kg for Hg and 1-30 μg/kg for Pb. Only the maximum concentrations of Hg established in the Brazilian legislation for fish destined for human consumption (0.5 mg/kg) were exceeded (in 16% of carnivorous species). The large between-species and seasonal differences observed for all these toxic elements are probably related to the seasonal behaviour and dietary habits of the different fish species. By contrast, essential trace element concentrations were low and not related to seasonal or dietary factors, and the observed differences may be at least partly related to the metabolism of each species. The associations between Hg and the essential trace elements Se, Fe, Co and Mn deserve special attention, as these trace elements may play a role in Hg cycling and methylation and merit further evaluation with the aim of reducing Hg toxicity in aquatic environments.
亚马孙河下游地区（巴西西北部帕拉州）深受矿业开采（特别是手工采金）和其他工业及集约化农业活动的影响，这些活动可能对水生态系统造成强烈影响。尽管这些影响包括各种有毒元素的污染，但迄今为止，仅考虑了汞的影响。在这项研究中，于 2015 年和 2016 年旱季和雨季测定了 351 个鱼类标本（包括碎屑食性鱼（Acarí，Pterygoplichthys pardalis）、杂食性鱼（Piranha，Pygocentrus nattereri；Pirarucu，Arapaima sp.）和肉食性鱼（Caparari，Pseudoplatystoma fasciatum；Tucunaré，Cichla ocellaris））的肉中有毒和痕量元素浓度。有毒元素残留浓度范围为：砷 2-238μg/kg 鲜重、镉 1-77μg/kg、汞 4-1922μg/kg 和铅 1-30μg/kg。只有在为人类消费而指定的鱼类中，汞的最大浓度（巴西法规规定的 0.5mg/kg）超标（肉食性鱼类中占 16%）。所有这些有毒元素的种间和季节性差异很大，可能与不同鱼类的季节性行为和饮食习惯有关。相比之下，必需痕量元素浓度较低，与季节性或饮食因素无关，观察到的差异至少部分可能与每个物种的新陈代谢有关。汞与必需痕量元素硒、铁、钴和锰之间的关系值得特别关注，因为这些痕量元素可能在汞循环和甲基化中发挥作用，需要进一步评估，以减少水生环境中的汞毒性。
