1] Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland [2] ETH, Swiss Federal Institute of Technology, 8006 Zürich, Switzerland.
State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China.
Nat Commun. 2014 Sep 2;5:4717. doi: 10.1038/ncomms5717.
The prevalence of terrestrial environments low in the essential trace element selenium (Se) results in large-scale Se deficiency worldwide. However, the underlying processes leading to Se-depleted environments have remained elusive. Here we show that over the last 6.8 million years (Ma) climatic factors have played a key role in the Se distribution in loess-paleosol sequences in the Chinese Loess Plateau (CLP), which lies in a severely Se-depleted region with a history of Se deficiency-related diseases. We use a combination of geochemical and paleoclimate data to demonstrate that during interglacial periods between 2.30 and 0.16 Ma, variations in the Se concentration in the CLP are potentially related to variability in Se input via East Asian monsoon-derived precipitation. Our results identify precipitation as an important controlling factor of Se distribution in monsoonal China. We suggest that atmospheric Se inputs via precipitation could also play an important role in other regions worldwide.
在地球上，普遍存在着某些微量元素硒（Se）含量较低的环境，这导致了全球范围内的硒缺乏现象。然而，导致这些缺硒环境出现的具体过程仍然难以捉摸。在这里，我们表明，在过去的 680 万年（Ma）中，气候因素在黄土-古土壤序列中的硒分布中发挥了关键作用，而这些黄土-古土壤序列位于中国黄土高原（CLP）中一个严重缺硒的地区，该地区有着与硒缺乏相关的疾病的历史。我们结合地球化学和古气候数据，证明了在 230 万至 16 万年前的间冰期，CLP 中硒浓度的变化可能与东亚季风带来的降水导致的硒输入的变化有关。我们的研究结果确定了降水是季风气候中国硒分布的一个重要控制因素。我们认为，通过降水进入大气的硒输入也可能在世界其他地区发挥重要作用。
