Centre for Earth Observation Science, Department of Environment and Geography, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2.
Environ Sci Technol. 2010 Aug 1;44(15):5805-11. doi: 10.1021/es100724y.
Twelve marine sediment cores from Hudson Bay, Canada, were collected to investigate the response of sub-Arctic marine sediments to atmospherically transported anthropogenic mercury (Hg). Modeling by a two-layer sediment mixing model suggests that the historical Hg deposition to most of the sediment cores reflects the known history of atmospheric Hg deposition in North America, with an onset of increasing anthropogenic Hg emissions in the late 1800s and early 1900s and a reduction of Hg deposition in the mid- to late-1900s. However, although anthropogenic Hg has contributed to a ubiquitous increase in Hg concentrations in sediments over the industrial era, the most elevated industrial-era sedimentary Hg concentrations only marginally exceed the upper preindustrial sedimentary Hg concentrations. Analysis of delta13C and relationship between Hg and organic matter capture suggests that the response of Hudson Bay sediments to changes in atmospheric Hg emissions is largely controlled by the particle flux in the system and that natural changes in organic matter composition and dynamics can cause variation in sedimentary Hg concentrations at least to the same extent as those caused by increasing anthropogenic Hg emissions.
从加拿大哈德逊湾采集了 12 个海洋沉积物岩芯，以研究亚北极海洋沉积物对大气传输的人为汞（Hg）的响应。通过两层沉积物混合模型进行的建模表明，大多数沉积物岩芯中的历史 Hg 沉积反映了北美大气 Hg 沉积的已知历史，在 19 世纪后期和 20 世纪初期人为 Hg 排放开始增加，在 20 世纪中后期 Hg 沉积减少。然而，尽管人为 Hg 导致了整个工业时代沉积物中 Hg 浓度的普遍增加，但最高的工业时代沉积 Hg 浓度仅略微超过前工业时代的沉积 Hg 浓度。对 delta13C 的分析以及 Hg 与有机物之间的关系捕捉表明，哈德逊湾沉积物对大气 Hg 排放变化的响应在很大程度上受系统中颗粒通量的控制，并且有机物组成和动态的自然变化至少可以引起与人为 Hg 排放增加相同程度的沉积物 Hg 浓度变化。
