Air Quality Processes Research Section, Air Quality Research Division, Science and Technology Branch Environment and Climate Change Canada, Government of Canada, Canada.
Air Quality Processes Research Section, Air Quality Research Division, Science and Technology Branch Environment and Climate Change Canada, Government of Canada, Canada.
Sci Total Environ. 2022 Sep 1;837:155802. doi: 10.1016/j.scitotenv.2022.155802. Epub 2022 May 10.
The Arctic region forms a unique environment with specific physical, chemical, and biological processes affecting mercury (Hg) cycles and limited anthropogenic Hg sources. However, historic global emissions and long range atmospheric transport has led to elevated Hg in Arctic wildlife and waterways. Continuous atmospheric Hg measurements, spanning 20 years, and increased monitoring sites has allowed a more comprehensive understanding of how Arctic atmospheric mercury is changing over time. Time-series trend analysis of TGM (Total Gaseous Mercury) in air was performed from 10 circumpolar air monitoring stations, comprising of high-Arctic, and sub-Arctic sites. GOM (gaseous oxidised mercury) and PHg (particulate bound mercury) measurements were also available at 2 high-Arctic sites. Seasonal mean TGM for sub-Arctic sites were lowest during fall ranging from 1.1 ng m Hyytiälä to 1.3 ng m, Little Fox Lake. Mean TGM concentrations at high-Arctic sites showed the greatest variability, with highest daily means in spring ranging between 4.2 ng m at Amderma and 2.4 ng m at Zeppelin, largely driven by local chemistry. Annual TGM trend analysis was negative for 8 of the 10 sites. High-Arctic seasonal TGM trends saw smallest decline during summer. Fall trends ranged from -0.8% to -2.6% yr. Across the sub-Arctic sites spring showed the largest significant decreases, ranging between -7.7% to -0.36% yr, while fall generally had no significant trends. High-Arctic speciation of GOM and PHg at Alert and Zeppelin showed that the timing and composition of atmospheric mercury deposition events are shifting. Alert GOM trends are increasing throughout the year, while PHg trends decreased or not significant. Zeppelin saw the opposite, moving towards increasing PHg and decreasing GOM. Atmospheric mercury trends over the last 20 years indicate that Hg concentrations are decreasing across the Arctic, though not uniformly. This is potentially driven by environmental change, such as plant productivity and sea ice dynamics.
北极地区形成了一个独特的环境，具有特定的物理、化学和生物过程，影响汞 (Hg) 循环和有限的人为 Hg 源。然而，历史上的全球排放和长距离大气传输导致北极野生动物和水道中的 Hg 含量升高。连续的大气 Hg 测量，跨越 20 年，并增加监测站点，使我们能够更全面地了解北极大气汞随时间的变化。从 10 个环极空气监测站对 TGM（总气态汞）的时间序列趋势进行了分析，这些监测站包括高北极和亚北极站点。在 2 个高北极站点也可以获得 GOM（气态氧化汞）和 PHg（颗粒结合汞）测量值。亚北极站点秋季的 TGM 季节性均值最低，范围从 1.1 ng m Hyytiälä 到 1.3 ng m Little Fox Lake。高北极站点的 TGM 浓度变化最大，春季的最高日均值在 Amderma 为 4.2 ng m，在 Zeppelin 为 2.4 ng m，主要受当地化学物质的驱动。10 个站点中有 8 个站点的年度 TGM 呈负趋势。高北极地区 TGM 的季节性趋势在夏季下降幅度最小。秋季趋势范围从 -0.8%到 -2.6%yr。在亚北极站点中，春季显示出最大的显著下降，范围从 -7.7%到 -0.36%yr，而秋季一般没有显著趋势。在 Alert 和 Zeppelin 的高北极地区 GOM 和 PHg 的形态分析表明，大气汞沉积事件的时间和组成正在发生变化。Alert 的 GOM 趋势全年都在增加，而 PHg 趋势则减少或不显著。Zeppelin 则相反，PHg 增加，GOM 减少。过去 20 年的大气汞趋势表明，北极地区的 Hg 浓度正在下降，但并不均匀。这可能是由环境变化驱动的，如植物生产力和海冰动态。
