Mercury methylation in rice paddies and its possible controlling factors in the Hg mining area, Guizhou province, Southwest China.
Mercury methylation in rice paddies and its possible controlling factors in the Hg mining area, Guizhou province, Southwest China.
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DOI：
10.1016/j.envpol.2016.05.001
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发表时间：
2016-08
影响因子：
8.9
通讯作者：
Lei Zhao;G. Qiu;C. Anderson;B. Meng;Ding-yong Wang;L. Shang;Haiyu Yan;Xinbin Feng
中科院分区：
文献类型：
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作者：
Lei Zhao;G. Qiu;C. Anderson;B. Meng;Ding-yong Wang;L. Shang;Haiyu Yan;Xinbin Feng
了解汞矿区稻田生态系统中汞（Hg）甲基化/去甲基化过程以及控制甲基汞（MeHg）产生的因素，对于评估稻米中甲基汞污染的风险至关重要。本研究选取了两个典型的汞污染矿区，一个是目前的手工开采矿区（沟溪），一个是废弃矿区（五坑）。我们在一个完整的水稻生长季节，在水稻土中的特定的甲基化/去甲基化速率常数合格。我们的研究结果表明，在水稻土中的甲基汞水平是一个功能的甲基化和去甲基化过程和净甲基化潜力在水稻土中反映了测量的甲基汞生产在任何时间点。硫酸盐对硫酸盐还原菌活性的刺激可能是汞在稻田中甲基化的重要代谢途径。我们认为，来自新的大气沉降的生物可利用的汞似乎是调节净甲基汞在稻田生产的主要因素。
Understanding mercury (Hg) methylation/demethylation processes and the factors controlling methylmercury (MeHg) production within the rice paddy ecosystem of Hg mining areas is critical to assess the risk of MeHg contamination in rice grain. Two typical Hg-contaminated mining sites, a current-day artisanal site (Gouxi) and an abandoned site (Wukeng), were chosen in this study. We qualified thein situspecific methylation/demethylation rate constants in rice paddy soil during a complete rice-growing season. Our results demonstrate that MeHg levels in rice paddy soil were a function of both methylation and demethylation processes and the net methylation potential in the rice paddy soil reflected the measured MeHg production at any time point. Sulfate stimulating the activity of sulfate-reducing bacteria was a potentially important metabolic pathway for Hg methylation in rice paddies. We suggest that bioavailable Hg derived from new atmospheric deposition appears to be the primary factor regulating net MeHg production in rice paddies.