Background

Environmental contamination by mercury is and will continue to be a serious risk for human health. Pollution of the terrestrial environment is particularly important as it is a place of human life and food production. This publication presents a review of the literature on issues related to mercury pollution of the terrestrial environment: soil and plants and their transformations.

Results

Different forms of atmospheric Hg may be deposited on surfaces by way of wet and dry processes. These forms may be sequestered within terrestrial compartments or emitted back into the atmosphere, and the relative importance of these processes is dependent on the form of Hg, the surface chemistry, and the environmental conditions. On the land surface, Hg deposition mainly occurs in the oxidized form (Hg²⁺), and its transformations are associated primarily with the oxidation–reduction potential of the environment and the biological and chemical processes of methylation. The deposition of Hg pollutants on the ground with low vegetation is as 3–5 times lower than that in forests. The estimation of Hg emissions from soil and plants, which occur mainly in the Hg⁰ form, is very difficult. Generally, the largest amounts of Hg are emitted from tropical regions, followed by the temperate zone, and the lowest levels are from the polar regions. Areas with vegetation can be ranked according to the size of the emissions as follows: forests > other areas (tundra, savannas, and chaparral) > agricultural areas > grassland ecosystems; areas of land devoid of vegetation emit more Hg than those with plants. In areas with high pollution, such as areas near Hg mines, the Hg content in soil and plants is much higher than in other areas.

Conclusions

Mercury is recognized as a toxic, persistent, and mobile contaminant; it does not degrade in the environment and becomes mobile because of the volatility of the element and several of its compounds. Atmospheric contamination by mercury continues to be one of the most important environmental problems in the modern world. The general conclusions were drawn from a review of the literature and presented in this paper.

中文翻译：

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地球环境中的汞：回顾

背景

汞对环境的污染现在并将继续是对人类健康的严重风险。陆地环境的污染尤为重要，因为它是人类生活和粮食生产的场所。该出版物介绍了有关与陆地环境汞污染有关的问题的文献：土壤和植物及其转化。

结果

可以通过湿法和干法将不同形式的大气Hg沉积在表面上。这些形式可能被隔离在陆地隔室内或释放回大气中，这些过程的相对重要性取决于汞的形式，表面化学性质和环境条件。在陆地表面，汞沉积主要以氧化形式（Hg ²⁺）发生，其转化主要与环境的氧化还原电位以及甲基化的生物和化学过程有关。汞含量低的植被地面上的汞沉积量比森林低3–5倍。估算土壤和植物中的汞排放，主要发生在汞中⁰形式，是非常困难的。通常，Hg排放量最多的是热带地区，其次是温带地区，最低的是H2O极地地区。可以根据排放量的大小对具有植被的区域进行如下排序：森林>其他区域（苔原，热带稀树草原和丛林）>农业区域>草地生态系统；没有植被的土地排放的汞比有植物的汞排放更多。在高污染地区，例如汞矿附近，土壤和植物中的汞含量远高于其他地区。

结论

汞被认为是有毒，持久和可移动的污染物；由于该元素及其几种化合物的挥发性，它在环境中不会降解并可以移动。汞对大气的污染仍然是现代世界中最重要的环境问题之一。一般结论是从文献综述中得出的，并在本文中进行了介绍。