Shao Junjuan, Shi Jianbo, Duo Bu, Liu Chengbin, Gao Yan, Fu Jianjie, Yang Ruiqiang, Jiang Guibin
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
J Environ Sci (China). 2016 Jan;39:22-28. doi: 10.1016/j.jes.2015.09.009. Epub 2015 Dec 8.
As a global pollutant, high levels of mercury (Hg) have been found in remote ecosystem due to the long range atmospheric transport. In this study, a total of 60 fish samples were collected from four rivers across the Tibetan Plateau to study the accumulation of Hg in remote and high-altitude aquatic environment. The total Hg (THg) and methylmercury (MeHg) in fish muscles ranged from 11 to 2097 ng/g dry weight (dw) (average: 819 ng/g dw) and from 14 to 1960 ng/g dw (average: 756 ng/g dw), respectively. Significantly positive linear relationships were observed between the THg (r=0.591, p<0.01, n=36) and MeHg concentrations (r=0.473, p<0.01, n=36) with the trophic level of fish from Lhasa River, suggesting trophic transfer and biomagnification of Hg in this aquatic ecosystem. Moreover, the THg levels in fish had significantly positive correlations with the length (r=0.316, p<0.05, n=60) and weight (r=0.271, p<0.05, n=60) of fish. The high levels of Hg were attributed to the slow growth and long lifespan of the fish under this sterile and cold environment. Risk assessment revealed that the consumption of Oxygymnocypris stewartii, Schizothorax macropogon, Schizothorax waltoni, Schizopygopsis younghusbandi and Schizothorax o'connori would lead to a high exposure to MeHg.
作为一种全球污染物，由于大气远距离传输，在偏远生态系统中已发现高浓度的汞（Hg）。在本研究中，从青藏高原的四条河流中总共采集了60个鱼类样本，以研究偏远和高海拔水生环境中汞的积累情况。鱼肌肉中的总汞（THg）和甲基汞（MeHg）含量分别为干重11至2097纳克/克（平均：819纳克/克干重）和14至1960纳克/克干重（平均：756纳克/克干重）。拉萨河鱼类的THg浓度（r = 0.591，p < 0.01，n = 36）和MeHg浓度（r = 0.473，p < 0.01，n = 36）与营养级之间存在显著的正线性关系，表明该水生生态系统中汞的营养级转移和生物放大作用。此外，鱼体内的THg水平与鱼的体长（r = 0.316，p < 0.05，n = 60）和体重（r = 0.271，p < 0.05，n = 60）显著正相关。汞含量高归因于这种无菌寒冷环境下鱼类生长缓慢和寿命长。风险评估显示，食用斯氏裸裂尻鱼、大鳞裂腹鱼、拉萨裂腹鱼、雅鲁藏布裂腹鱼和异齿裂腹鱼会导致甲基汞的高暴露风险。
