Zou Meng-Yao, Ran Yong, Gong Jian, Mai Bi-Xian, Zeng Eddy Y
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
Environ Sci Technol. 2007 Dec 15;41(24):8262-7. doi: 10.1021/es071956d.
Soils play an important role in the distribution and biogeochemical cycling of polybrominated diphenyl ethers (PBDEs) as they are a major reservoir and sink for PBDEs due to their large sorption capacity. In this study, concentrations, compositional profiles, mass inventories, and fate of sigma9PBDEs (28, 47, 66, 100, 99, 154, 153, 138, 183) and BDE 209 were investigated in 33 surface soils, six profile soils, and three point-source polluted soils (close to e-waste dismantling sites) from the Pearl River Delta (PRD), China. The concentrations of sigma9PBDEs and BDE 209 in the surface soils ranged from 0.13 to 3.81 ng/g with an average of 1.02 ng/g and from 2.38 to 66.6 ng/g with an average of 13.8 ng/g, respectively, and ranged from 1.93 to 19.5 ng/g and from 25.7 to 102 ng/g, respectively, in the point-source contaminated soils. The PBDE compositional patterns in the surface soils indicated deca-BDE, penta-BDE, and octa-BDE products as the main sources, but those in the point-source samples suggested deca-BDE and octa-BDE technical mixtures as the dominant sources. The mass inventories of PBDEs in soils of the PRD were estimated at 3.98 and 44.4 t for sigma9PBDEs and BDE 209, respectively. The average loading of PBDEs in the soils was comparable to that in the sediments of the Pearl River Estuary, suggesting that soil erosion and surface runoff are an important mode to transport PBDEs from terrestrial sources to oceans in the PRD. Individual BDE congeners, sigma9PBDEs, and PBDE 209, were significantly correlated with total organic carbon (TOC), and a good regression (except for BDE 47) between the logarithms of TOC-normalized BDE average concentrations and their log K(ow) was also obtained, indicating that sorption of PBDEs on soil organic matter governed their spatial distribution, transportation, and fate in the soils. Predicted aqueous and gaseous concentrations of PBDEs were derived from the soil-water and soil-air partitioning models, respectively, and good agreements were obtained between the predicted and previously reported values. BDE 47 and/or 28 did not appear to follow the same trend for these models, an indication that an portion of them was likely the biodegradation byproducts in soils.
土壤在多溴二苯醚（PBDEs）的分布和生物地球化学循环中起着重要作用，由于其具有较大的吸附能力，土壤是PBDEs的主要储存库和汇。本研究调查了中国珠江三角洲（PRD）33个表层土壤、6个剖面土壤和3个点源污染土壤（靠近电子垃圾拆解场）中σ9PBDEs（28、47、66、100、99、154、153、138、183）和BDE 209的浓度、组成特征、质量存量及归宿。表层土壤中σ9PBDEs和BDE 209的浓度分别为0.13至3.81 ng/g，平均为1.02 ng/g，以及2.38至66.6 ng/g，平均为13.8 ng/g；点源污染土壤中的浓度分别为1.93至19.5 ng/g和25.7至102 ng/g。表层土壤中PBDE的组成模式表明十溴二苯醚、五溴二苯醚和八溴二苯醚产品是主要来源，但点源样品中的组成模式表明十溴二苯醚和八溴二苯醚工业混合物是主要来源。珠江三角洲土壤中PBDEs的质量存量估计σ9PBDEs和BDE 209分别为3.98 t和44.4 t。土壤中PBDEs的平均负荷与珠江河口沉积物中的相当，这表明土壤侵蚀和地表径流是珠江三角洲地区将PBDEs从陆地源输送到海洋的重要途径。单个BDE同系物、σ9PBDEs和PBDE 209与总有机碳（TOC）显著相关，并且在TOC归一化BDE平均浓度的对数与其log K(ow)之间也获得了良好的回归关系（BDE 47除外），这表明PBDEs在土壤有机质上的吸附控制了它们在土壤中的空间分布、迁移和归宿。PBDEs的预测水相和气态浓度分别来自土壤 - 水和土壤 - 空气分配模型，预测值与先前报道的值之间取得了良好的一致性。BDE 47和/或28在这些模型中似乎没有遵循相同的趋势，这表明它们中的一部分可能是土壤中的生物降解副产物。
