青藏高原中部地区表层土壤中多溴联苯醚的分布特征及影响因素

从青藏高原中部地区采集16个表层土壤样品,并对土壤中42种多溴联苯醚(PBDEs)同系物含量、有机碳含量、矿物含量及土壤粒径分布进行了测试分析,主要研究该区域土壤理化性质对PBDEs的含量、分布及同系物构成的影响。结果表明,PBDEs的含量范围为17.03～298.29 ng/kg(干重),其中低溴联苯醚(1～6溴)占总量的90%以上。研究还发现BDE-3在同系物中含量最高,其次为BDE-2和BDE-1。在所有42个样品中BDE-209均被检出,但平均含量仅为1.25 ng/kg。PBDEs成分组成表明它们主要来源于长距离的大气运移。研究还发现粘土矿物对PBDEs的影响结果与土壤有机碳相似,但影响效果更显著。相关性分析结果表明,在高原地区土壤粘土矿物是影响PBDEs分布的主要因素之一。

Polybrominated Diphenyl Ethers (PBDEs) in Surface Soil from Central Tibetan Plateau, China: Congeners Distribution and Controlling Factors

Surface soil samples were collected at 16 stations across central Tibetan Plateau.The concentration and composition of polybrominated diphenyl ethers(PBDEs),soil organic carbon,minerals and particle size distribution were determined to assess the level and identify the influence of soil on PBDEs.The soil concentration of ΣPBDEs ranged from 17.03-298.29 ng/kg(dw).The fraction of BDEs from mono-to hexa-brominated DEs contributes approximately 90% of the ΣPBDEs.There are 42 BDE congeners were detected in all,among which BDE-3 was the most abundant,followed by BDE-2 and BDE-1.A wide variety of other congeners were also detected including BDE-209,with the average concentration 1.25 ng/kg(dw).It suggested the PBDEs in the study area were transported by long range atmospheric transport(LRAT).This influence of clay minerals on each fraction of BDEs is similar to that obtained for SOC.The coefficient of determination(r2) is higher for the clays than for SOC.The results of correlation analysis suggest that,in Tibetan Plateau,clay minerals are one of main factors to affect the distribution of PBDEs in soil.