• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Environmental Science & Technology >Rapid reduction and reemission of mercury deposited into snowpacks during atmospheric mercury depletion events at Churchill, Manitoba, Canada
【24h】

Rapid reduction and reemission of mercury deposited into snowpacks during atmospheric mercury depletion events at Churchill, Manitoba, Canada

机译：在加拿大曼尼托巴省丘吉尔的大气汞消耗事件中，迅速减少和释放积雪中的汞

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Mercury (Hg) in some Arctic marine mammals has increased to levels that may be toxic to Northern peoples consuming them as traditional food. It has been suggested that sunlight-induced atmospheric reactions called springtime atmospheric Hg depletion events (AMDEs) result in the loading of similar to 150 - 300 tons of Hg to the Canadian Arctic archipelago each spring and that AMDEs are the ultimate source of Hg to Arctic foodwebs. AMDEs result from the oxidation of gaseous elemental Hg-0 (GEM) in Arctic atmospheres to reactive gaseous Hg (RGM) and particulate Hg (pHg), both of which fall out of the atmosphere to snowpacks. We studied the springtime cycling of Hg between air and snowpacks near Churchill, Manitoba, for 2 years to determine the net input of Hg to Hudson Bay from AMDEs. In 2004, we monitored atmospheric concentrations of GEM, pHg, and RGM while simultaneously measuring concentrations of total Hg (THg) in surface snow collected over the sea ice on Hudson Bay. During numerous springtime AMDEs, concentrations of THg in surface snow increased, often to over 60 ng/L, demonstrating that AMDEs resulted in deposition of oxidized Hg (Hg(II)) to snowpacks. However, immediately following AMDEs, average concentrations of THg in snow declined drastically from between 67.8 +/- 97.7 ng/L during AMDEs to only 4.25 +/- 1.85 ng/L four or more days following them. In 2003, we measured THg in surface snow collected daily over the sea ice and total gaseous Hg (TGM) concentrations in the interstitial airspaces of snowpacks. When concentrations of THg in the surface snow decreased, concentrations of TGM in interstitial airspaces of the snowpack increased sharply from between similar to 1.4 - 3.4 ng/m(3) to between similar to 20 - 150 ng/m(3), suggesting that there was a reduction of deposited Hg(II) to GEM, which then diffused out of snowpacks. At snowmelt in both 2003 and 2004, average concentrations of THg in meltwater collected over Hudson Bay were only 4.04 +/- 2.01 ng/L. Using concentrations of THg in meltwater and snow water equivalent, we estimated a net springtime loading of only 2.1 +/- 1.7 mg/ha of Hg to Hudson Bay from AMDEs, indicating that only a small portion of the Hg(II) deposited during AMDEs enters Hudson Bay each spring.
机译：在某些北极海洋哺乳动物中，汞的含量已增加到可能对北方人将它们作为传统食品消费的有毒水平。有人提出，阳光引起的大气反应被称为春季大气中的汞消耗事件（AMDE），导致每年春季加拿大北极群岛的汞含量接近150至300吨，而AMDE是北极汞的最终来源。食物网。 AMDE是由北极大气中的气态元素Hg-0（GEM）氧化为反应性气态Hg（RGM）和颗粒Hg（pHg）所引起的，两者均从大气中掉落到积雪中。我们研究了曼尼托巴省丘吉尔附近空气与积雪之间汞的春季循环，历时2年，以确定从AMDE到哈德逊湾的汞净输入量。 2004年，我们监测了GEM，pHg和RGM的大气浓度，同时测量了哈德逊湾海冰上收集的表层积雪中总Hg（THg）的浓度。在许多春季AMDE期间，表雪中THg的浓度增加，通常超过60 ng / L，这表明AMDE导致氧化的Hg（Hg（II））沉积在积雪堆上。但是，紧接AMDE之后，雪中THg的平均浓度从AMDE期间的67.8 +/- 97.7 ng / L急剧下降至其后四天或更长时间的仅4.25 +/- 1.85 ng / L。在2003年，我们测量了每天从海冰上收集的地表雪中的THg和积雪的间隙空域中的总气态Hg（TGM）浓度。当表层积雪中THg的浓度降低时，积雪的间隙空域中TGM的浓度从相似的1.4-3.4 ng / m（3）急剧增加到相似的20-150 ng / m（3）之间，这表明沉积的Hg（II）减少到GEM，然后从积雪中扩散出去。在2003年和2004年的融雪期，哈德逊湾上空融水中THg的平均浓度仅为4.04 +/- 2.01 ng / L。使用融水和雪水当量中的三价汞浓度，我们估计从AMDE到哈德逊湾的净春季汞负荷仅为2.1 +/- 1.7 mg / ha汞，这表明在AMDE期间只有一小部分Hg（II）沉积每年春天进入哈德逊湾。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号