Unidad de Espectroscopía, División de Química, Departamento de Tecnología, CIEMAT, Av. Complutense, 40, E-28040 Madrid, Spain.
Environ Sci Process Impacts. 2014 May;16(5):1069-75. doi: 10.1039/c3em00710c.
Mercury contamination from historic cinnabar mines represents a potential risk to the environment. Asturias, in Northern Spain, was one of the largest metallurgic and mining producer areas of Hg in Europe during the 20th century until the end of activities in 1974. Mining operations have caused Hg release and dispersion throughout the area. In this study, soils collected from calcine piles and surrounding soils at an abandoned Hg mine and metallurgical plant in Mieres (Asturias, Spain) were distributed in different particle-size subsamples. Fractionation of Hg was performed by means of a Hg-specific sequential extraction procedure complemented with the selective determination of organic Hg fraction by a specific extraction method. Extremely high concentrations of total Hg were found in calcine piles. Concentrations and mobility of Hg decreased markedly with the distance in soils located 25 m both above and below the chimney of the metallurgical plant. The sequential extraction results indicated that Hg is primarily found as elemental Hg followed by sulfide Hg in the finest subsamples. However, this distribution is inverted in the coarser grain fractions where sulfide Hg prevails. Calcine piles exhibited exceptionally high values of mobile Hg (up to 5350 μg g(-1) in the finest subsample). Accumulation of Hg in the elemental Hg fraction was observed at decreasing grain size which is indicative of deposition of Hg vapors from the metallurgical plant. Enrichment of sulfide Hg was found in the finest subsamples of soils sampled below the chimney (up to 99 μg g(-1)). Significant organic Hg contents were observed in the soil samples (up to 2.8 μg g(-1)), higher than those found in other abandoned Hg mining sites. A strong correlation was observed between organic Hg and Hg humic and fulvic complexes, as well as with the elemental Hg fraction. This indicates that both humic and fulvic material and elemental Hg must be the primary variables controlling Hg methylation in these soils.
历史朱砂矿造成的汞污染对环境构成了潜在威胁。西班牙阿斯图里亚斯（Asturias）在 20 世纪曾是欧洲最大的冶金和汞矿生产区之一，直到 1974 年活动结束。采矿作业导致汞释放和分散到整个地区。在这项研究中，从西班牙米耶雷斯（Mieres）一座废弃的汞矿和冶金厂的煅烧堆和周围土壤中采集的土壤被分为不同粒径的亚样本。采用特定的提取方法对有机汞部分进行了选择性测定，通过汞特异性顺序提取程序对汞进行了分级。在煅烧堆中发现了极高浓度的总汞。在冶金厂烟囱上方和下方 25 米处的土壤中，汞的浓度和迁移率随着距离的增加而显著降低。顺序提取结果表明，汞主要以元素汞的形式存在，其次是最细亚样本中的硫化汞。然而，在较粗的颗粒分数中，这种分布是相反的，其中硫化汞占优势。煅烧堆表现出极高的可移动汞值（最细亚样本中高达 5350μg/g）。随着粒径的减小，观察到元素汞部分中汞的积累，这表明汞蒸气从冶金厂沉积。在烟囱下方采集的土壤的最细亚样本中发现了硫化汞的富集（高达 99μg/g）。在土壤样品中观察到显著的有机汞含量（高达 2.8μg/g），高于在其他废弃的汞矿开采点中发现的含量。观察到有机汞与 Hg 腐殖质和富里酸络合物以及元素汞部分之间存在很强的相关性。这表明腐殖质和富里酸物质以及元素汞必须是控制这些土壤中汞甲基化的主要变量。
