State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China; School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China.
Sci Total Environ. 2015 Apr 1;511:399-406. doi: 10.1016/j.scitotenv.2014.12.097. Epub 2015 Jan 5.
Forty-two congeners of polybrominated diphenyl ethers (PBDEs) were detected for each of 27 surface-soil samples collected at an area near the Changwengluozha Glacier in the Central Tibetan Plateau (CTP), a remote background area at altitude from 5080 to 5217 m. The total concentrations of BDEs in soils ranged from 15.3 to 248.0 ng/kg, which were found to be positively correlated with the clay contents in the soil. In addition to adsorption, the clay was found to serve as a catalyst for the debromination of PBDEs in soils. Three pieces of evidence confirmed that the clay was significantly correlated with the debrominating transformation from the higher brominated congeners to the less brominated congeners. The transforming rate was found to be increased 3.5% with a 10% increase in clays. Debromination is an important way for highly brominated congeners to transform into lighter brominated congeners that are more toxic. This study first provided the direct field evidences for clays contributing to the debromination of PBDEs, and elucidated the importance of it in PBDEs' environmental fate.
在青藏高原中部昌翁公路附近的一个偏远背景地区（海拔 5080 至 5217 米），采集了 27 个表层土壤样本，每个样本都检测到了 42 种多溴二苯醚（PBDEs）同系物。土壤中 BDEs 的总浓度范围为 15.3 至 248.0ng/kg，发现其与土壤中的粘土含量呈正相关。除了吸附作用外，粘土还被发现是土壤中 PBDEs 脱溴反应的催化剂。有三个证据证实了粘土与从高溴代同系物向低溴代同系物的脱溴转化有显著相关性。发现随着粘土含量增加 10%，转化速率增加了 3.5%。脱溴是高溴代同系物转化为毒性更大的低溴代同系物的重要途径。本研究首次为粘土在 PBDEs 脱溴中的作用提供了直接的现场证据，并阐明了其在 PBDEs 环境归宿中的重要性。
