Poissant Laurier, Zhang Hong H, Canário João, Constant Philippe
Environment Canada, Science and Technology branch Montréal, Québec, Canada.
Sci Total Environ. 2008 Aug 1;400(1-3):173-211. doi: 10.1016/j.scitotenv.2008.06.050. Epub 2008 Aug 15.
Mercury (Hg) contamination in tundra region has raised substantial concerns, especially since the first report of atmospheric mercury depletion events (AMDEs) in the Polar Regions. During the past decade, steady progress has been made in the research of Hg cycling in the Polar Regions. This has generated a unique opportunity to survey the whole Arctic in respect to Hg issue and to find out new discoveries. However, there are still considerable knowledge gaps and debates on the fate of Hg in the Arctic and Antarctica, especially regarding the importance and significance of AMDEs vs. net Hg loadings and other processes that burden Hg in the Arctic. Some studies argued that climate warming since the last century has exerted profound effects on the limnology of High Arctic lakes, including substantial increases in autochthonous primary productivity which increased in sedimentary Hg, whereas some others pointed out the importance of the formation and postdeposition crystallographic history of the snow and ice crystals in determining the fate and concentration of mercury in the cryosphere in addition to AMDEs. Is mercury re-emitted back to the atmosphere after AMDEs? Is Hg methylation effective in the Arctic tundra? Where the sources of MeHg are? What is its fate? Is this stimulated by human made? This paper presents a critical review about the fate of Hg in the Arctic tundra, such as pathways and process of Hg delivery into the Arctic ecosystem; Hg concentrations in freshwater and marine ecosystems; Hg concentrations in terrestrial biota; trophic transfer of Hg and bioaccumulation of Hg through food chain. This critical review of mercury fates and contamination in the Arctic tundra ecosystem is assessing the impacts and potential risks of Hg contamination on the health of Arctic people and the global northern environment by highlighting and "perspectiving" the various mercury processes and concentrations found in the Arctic tundra.
苔原地区的汞（Hg）污染引发了人们的高度关注，尤其是自极地地区首次报道大气汞消耗事件（AMDEs）以来。在过去十年中，极地地区汞循环的研究取得了稳步进展。这为全面调查北极地区的汞问题并获得新发现提供了独特的机会。然而，在北极和南极地区汞的归宿方面，仍存在相当大的知识空白和争议，特别是关于AMDEs与净汞负荷以及北极地区其他汞负担过程的重要性和意义。一些研究认为，自上世纪以来的气候变暖对北极高海拔湖泊的湖沼学产生了深远影响，包括本地初级生产力大幅增加，进而导致沉积汞增加；而另一些研究则指出，除了AMDEs之外，冰雪晶体的形成和沉积后晶体学历史在决定冰冻圈中汞的归宿和浓度方面也很重要。AMDEs之后汞是否会重新释放回大气中？汞在北极苔原中是否会发生甲基化？甲基汞的来源在哪里？其归宿如何？这是由人为因素刺激的吗？本文对北极苔原中汞的归宿进行了批判性综述，例如汞进入北极生态系统的途径和过程；淡水和海洋生态系统中的汞浓度；陆地生物群中的汞浓度；汞的营养级转移以及通过食物链的汞生物累积。对北极苔原生态系统中汞的归宿和污染的这一批判性综述，通过突出和“透视”北极苔原中发现的各种汞过程和浓度，评估了汞污染对北极居民健康和全球北部环境的影响及潜在风险。
