Roos-Barraclough F, Givelet N, Cheburkin Andriy K, Shotyk W, Norton S A
Institute of Geological Sciences, University of Berne, Baltzerstrasse 1-3, CH-3012 Berne, Switzerland.
Environ Sci Technol. 2006 May 15;40(10):3188-94. doi: 10.1021/es051945p.
Using Br and Se as reference elements, the natural and anthropogenic fluxes of atmospheric Hg were reconstructed for the past 10,000 years using peat cores from Caribou Bog, ME. In the ombrotrophic peat layers, the average background Hg accumulation rate (AR) was 1.7 +/- 1.3 microg m(-2) year(-1) which is comparable with the natural rate of atmospheric Hg accumulation reported in other retrospective studies. The average Hg AR determined using all peat samples dating from preindustrial times, including minerotrophic peat, was slightly greater (3.1 +/- 2.3 microg m(-2) year(-1)) which may reflect differences in canopy interception due to the changes in plant communities, aquatic inputs, or possibly climatic factors. The maximum Hg AR (32 microg m(-2) year(-1)) occurred ca. 1961 A.D. In samples predating the settlement by Europeans, there is a linear correlation between the AR of Hg and those of Br and Se; this relationship allows both Br and Se to be used to calculate the natural AR of Hg (Hgnat). The difference between Hg AR and Hg(nat) is the Hg AR in excess of background (Hg(ex)). Because Hg(ex) was positive only after ca. 1840 A.D., it is assumed to represent the anthropogenic Hg component. By the late 19th century, Hg(ex) deposition was equal to the natural flux. At the peak in Hg deposition in 1961 A.D., Hgex made up >90% of total atmospheric Hg deposition. The AR in the uppermost peat decreased to 25% of peak values by 2000 A.D.
以溴（Br）和硒（Se）作为参考元素，利用缅因州驯鹿沼泽地的泥炭芯重建了过去一万年大气汞的自然和人为通量。在贫营养泥炭层中，汞的平均背景积累速率（AR）为1.7±1.3微克/平方米·年，这与其他回顾性研究报道的大气汞自然积累速率相当。使用所有可追溯到工业化前时期的泥炭样本（包括矿质营养泥炭）确定的汞平均AR略高（3.1±2.3微克/平方米·年），这可能反映了由于植物群落变化、水生输入或可能的气候因素导致的冠层截留差异。汞的最大AR（32微克/平方米·年）出现在公元1961年左右。在欧洲人定居之前的样本中，汞的AR与溴和硒的AR之间存在线性关系；这种关系使得溴和硒都可用于计算汞的自然AR（Hgnat）。汞AR与Hg（nat）之间的差值是超过背景值的汞AR（Hg（ex））。由于Hg（ex）仅在公元1840年左右之后为正值，因此假定其代表人为汞成分。到19世纪后期，Hg（ex）的沉积量与自然通量相等。在公元1961年汞沉积量达到峰值时，Hg（ex）占大气汞总沉积量的比例超过90%。到公元2000年，最上层泥炭中的AR降至峰值的25%。
