State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
Sci Total Environ. 2012 Apr 1;421-422:59-72. doi: 10.1016/j.scitotenv.2011.09.024. Epub 2012 Jan 4.
China has become the largest contributor of anthropogenic atmospheric mercury (Hg) in the world owing to its fast growing economy and the largest of populations. Over the last two decades, Hg has become of increasing environmental concern in China and much has been published on its distribution, transportation, methylation, and bioaccumulation in aquatic systems and areas of geologic resource extraction contaminated sites, such as coal-fired power plants, non-ferrous smelters, Hg mining and retorting sites, Au amalgam, landfills, chemical plants, etc.. Environmental compartments, like soil, water, air, and crop from areas of geologic resource extraction contamination, especially from Hg mining regions, exhibit elevated values of total-Hg and MMHg. Risk assessments indicate that the consumption of rice, which has a high bioaccumulation of MMHg, has become the dominant pathway of MMHg exposure of inhabitants living in Hg mining areas. Low concentrations less than 5ngl(-1) in total-Hg can be observed in rivers from remote areas, however, high concentrations that reached 1600ngl(-1) in total-Hg can be found in rivers from industrial and urban areas. The studies of hydropower reservoirs of southwest China indicated the old reservoirs act as net sinks for total-Hg and net sources of MMHg, while newly established ones act as net sinks for both total-Hg and MMHg, which is in sharp contrast to the evolution of biomethylation in reservoirs established in the boreal belt of North America and Eurasia. Fish from those reservoirs have relatively low levels of total-Hg, which do not exceed the maximum total-Hg limit of 0.5mgkg(-1) recommended by WHO. Currently, however, there is still a large data gap regarding Hg even in the areas mentioned above in China, which results in poor understanding of its environmental biogeochemistry. Moreover, for a better understanding of human and environmental health effects caused by the fast growing economy, long-term Hg monitoring campaigns are urgently needed.
中国经济快速增长，人口众多，已成为全球人为大气汞（Hg）的最大贡献者。在过去的二十年中，Hg 在中国的环境问题中越来越受到关注，并且已经发表了很多关于其在水生系统和地质资源开采污染地区（如燃煤电厂、有色冶炼厂、Hg 采矿和蒸馏场、金汞合金、垃圾填埋场、化工厂等）中的分布、迁移、甲基化和生物累积的研究。来自地质资源开采污染地区的环境介质，如土壤、水、空气和作物，总汞（Hg）和甲基汞（MMHg）的含量都很高。风险评估表明，Hg 矿区居民的主要 MMHg 暴露途径是食用具有高 MMHg 生物累积性的大米。在偏远地区的河流中可以观察到总 Hg 浓度低于 5ng/L 的低浓度，但在工业和城市地区的河流中可以发现高达 1600ng/L 的高浓度。对中国西南地区水电水库的研究表明，旧水库是总 Hg 的净汇和 MMHg 的净源，而新建立的水库是总 Hg 和 MMHg 的净汇，这与北美和欧亚大陆的北方带建立的水库中生物甲基化的演变形成鲜明对比。这些水库中的鱼类总 Hg 水平相对较低，不超过世界卫生组织（WHO）建议的 0.5mg/kg 的最大总 Hg 限量。然而，即使在中国上述提到的地区，目前仍然存在很大的数据差距，这导致对其环境生物地球化学的了解不足。此外，为了更好地了解快速增长的经济对人类和环境健康的影响，迫切需要进行长期的 Hg 监测活动。
