德国亚琛工业大学Schwarzbauer Jan课题组在研究中取得进展。他们的研究发现青藏高原永久冻土带中存在大量卤化有机化学物质。相关论文于2023年10月23日发表在《自然—地球科学》杂志上。
据悉，极地地区的永久冻土可能储存着大量有毒化学物质，包括与卤素结合的有机化合物。从融化的永久冻土中释放出的这种卤化有机化学品(HOC)代表了全球对气候变化的潜在关注。然而，HOC的确切库存仍然不确定，因为传统的分析技术在很大程度上忽略了不可提取的残留物。
研究人员提出了青藏高原多年冻土土壤中HOC的清单，主题是在常规溶剂提取后逐步进行化学处理，以释放和分析不可提取的残留物。课题组人员鉴定出270多种HOC，总平均浓度为310,000ng g-1，其中18万ng g-1，根据它们的分子结构，是自然地结合在一起的。研究人员还意外地发现不可提取残留物的高分数，贡献了超过99%的总HOC，远高于其他土壤和沉积物的报告。高达85%的不可提取的残留物被物理地困在土壤中，而不是被化学束缚，这样，如果土壤性质发生变化，它们很容易被重新激活。研究人员认为，在气候变暖的情况下，青藏高原多年冻土中大量的HOC储量对当地生态系统构成了潜在的重要风险。
附：英文原文
Title: Substantial halogenated organic chemicals stored in permafrost soils on the Tibetan Plateau
Author: Zhu, Xiaojing, Yang, Fan, Li, Zhen, Fang, Mingliang, Ma, Suping, Zhang, Ting, Li, Cunlin, Guo, Qiulei, Wang, Xiaoping, Zhang, Gan, Ji, Rong, Schffer, Andreas, Wang, Xiaofei, Ye, Xingnan, Chen, Yingjun, Wang, Lin, Chen, Jianmin, Xing, Baoshan, Wang, Zimeng, Schwarzbauer, Jan
Issue&Volume: 2023-10-23
Abstract: Permafrost in the polar regions potentially stores large amounts of toxic chemicals, including organic compounds bound with halogens. The release of such halogenated organic chemicals (HOC) from thawing permafrost represents a potential global concern with climate change. However, the exact inventory of HOC remains uncertain because conventional analytical techniques largely overlook nonextractable residues. Here we present an inventory of HOC in permafrost soils sampled from the Tibetan Plateau using stepwise chemical treatment following conventional solvent extraction to release and analyse the nonextractable residues. We identify more than 270 types of HOC, with total mean concentration of 310,000ng g1, of which 180,000ng g1 are naturally sourced based on their molecular structures. We also find unexpectedly high fractions of the nonextractable residues, contributing more than 99% of the total HOC, much higher than those reported for other soils and sediments. Up to 85% of the nonextractable residues are physically entrapped in soils rather than chemically bound, such that they could readily be remobilized if soil properties change. We suggest that this substantial stock of HOC in Tibetan Plateau permafrost poses potentially important future risks to local ecosystems in a warming climate.
DOI: 10.1038/s41561-023-01293-1
Source: https://www.nature.com/articles/s41561-023-01293-1