Liu Hong-Wei, Yu Ben, Yang Lin, Wang Lin-Lin, Fu Jian-Jie, Liang Yong, Bu Duo, Yin Yong-Guang, Hu Li-Gang, Shi Jian-Bo, Jiang Gui-Bin
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China; 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.
J Hazard Mater. 2020 Dec 5;400:123211. doi: 10.1016/j.jhazmat.2020.123211. Epub 2020 Jun 17.
Understanding the geochemical cycle of mercury (Hg) in the high-altitude Tibetan Plateau is of great value for studying the long-range transport of Hg. Herein, speciation and isotopic compositions of Hg in the muscle and feathers of upland buzzards (Buteo hemilasius) were studied to trace the terrestrial transformation of Hg in the Tibetan Plateau. Very low Hg content and relatively low δHg values (feather: -0.77 ± 0.50‰, n = 9, muscle: -1.29 ± 0.29‰, n = 13, 1SD) were observed in upland buzzards. In contrast, the ΔHg values could be as high as 2.89‰ in collected samples. To our knowledge, this is the highest ΔHg value reported in avian tissues. Moreover, upland buzzards showed significantly different ΔHg values from fish collected from the same region, suggesting different generation and transformation processes of methylmercury (MeHg) in terrestrial and aquatic ecosystems. We speculated that different percentages of Hg undergoing photochemical reactions and contributions of atmospheric MeHg were possible reasons for observed differences. The results provide new clues for different circulation histories of Hg in terrestrial and aquatic ecosystems, which will be critical for further study of geochemical cycle and ecological risk of Hg in the environment.
了解高海拔青藏高原汞（Hg）的地球化学循环对于研究汞的长距离传输具有重要价值。在此，对高山兀鹫（Buteo hemilasius）肌肉和羽毛中汞的形态及同位素组成进行了研究，以追踪青藏高原汞的陆地转化过程。在高山兀鹫中观察到极低的汞含量和相对较低的δHg值（羽毛：-0.77±0.50‰，n = 9，肌肉：-1.29±0.29‰，n = 13，1SD）。相比之下，所采集样本中的ΔHg值可能高达2.89‰。据我们所知，这是鸟类组织中报道的最高ΔHg值。此外，高山兀鹫的ΔHg值与从同一地区采集的鱼类显著不同，表明陆地和水生生态系统中甲基汞（MeHg）的生成和转化过程不同。我们推测，汞发生光化学反应的不同百分比以及大气中甲基汞的贡献可能是观察到差异的原因。这些结果为陆地和水生生态系统中汞的不同循环历史提供了新线索，这对于进一步研究环境中汞的地球化学循环和生态风险至关重要。
