State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, PR China; Department of International Environmental and Agricultural Science (IEAS), Tokyo University of Agriculture and Technology (TUAT) 3-5-8, Saiwai-Cho, Fuchu-Shi, Tokyo 1838509, Japan.
Centre for Environmental Sciences, Central University of South Bihar, BIT Campus, Patna 800014, Bihar, India.
Environ Pollut. 2018 Feb;233:642-654. doi: 10.1016/j.envpol.2017.10.104. Epub 2017 Nov 5.
While various investigations have been driven on polybrominated diphenyl ethers (PBDEs) and other flame retardants (FRs) in different framework around the world, information about contamination and fate of PBDEs and other FRs in developing countries especially in the Indian subcontinent is uncommon. Nepal being located in the Indian subcontinent, very little is known about contamination level of semi-volatile organic pollutants discharged into the environment. This motivated us to investigate the environmental fate of halogenated flame retardant (HFRs) in Nepalese condition. In this study, we investigated the concentration, fate, and sources of 9 PBDEs, 2 dechlorane plus isomers (DPs), and 6 novel brominated flame retardants (NBFRs). Moreover, air-soil exchange and soil-air partitioning were also evaluated to characterize the pattern of air-soil exchange and environmental fate. In general, the concentrations of NBFRs in soil were more prevalent than PBDEs and DPs, and accounted 95% of ∑HFRs. By and large, the concentrations of NBFRs and DPs were measured high in Kathmandu, while PBDEs level exceeded in Pokhara. Principal component analysis (PCA) study suggested contributions from commercial penta-, octa-, and deca-BDEs products and de-bromination of highly brominated PBDEs as the significant source of PBDEs. Likewise, low f ratio suggested DPs in soil might have originated from long-range atmospheric transport from remote areas, while high levels of decabromodiphenyl ethane (DBDPE) in soil were linked with the use of wide varieties of consumer products. The estimated fugacity fraction (ff) for individual HFR was quite lower (<0.05) than equilibrium value, suggesting that deposition and net transport from air to the soil is overwhelming. Soil-air partitioning study revealed neither octanol-air partition coefficient (K) nor black carbon partition coefficient (K) is an appropriate surrogate for soil organic matter (SOM), subsequently, absorption by SOM has no or little role in the partitioning of HFRs.
虽然世界各地已经开展了关于多溴二苯醚 (PBDEs) 和其他阻燃剂 (FRs) 的各种研究，但有关发展中国家（特别是印度次大陆）PBDEs 和其他 FRs 的污染和归宿的信息却很少。尼泊尔位于印度次大陆，对排放到环境中的半挥发性有机污染物的污染水平知之甚少。这促使我们调查卤代阻燃剂 (HFRs) 在尼泊尔的环境归宿。在这项研究中，我们调查了 9 种 PBDEs、2 种十氯酮加异构体 (DPs) 和 6 种新型溴化阻燃剂 (NBFRs) 的浓度、归宿和来源。此外，还评估了空气-土壤交换和土壤-空气分配，以描述空气-土壤交换和环境归宿的模式。总的来说，NBFRs 在土壤中的浓度比 PBDEs 和 DPs 更为普遍，占∑HFRs 的 95%。总的来说，NBFRs 和 DPs 的浓度在加德满都较高，而 PBDEs 的浓度在博克拉较高。主成分分析 (PCA) 研究表明，商用五溴、八溴和十溴 BDE 产品以及高度溴化 PBDE 的脱溴是 PBDEs 的重要来源。同样，低 f 比表明土壤中的 DPs 可能来自远程大气传输的远程地区，而土壤中十溴二苯乙烷 (DBDPE) 的高水平与广泛使用各种消费品有关。个别 HFR 的估计逸度分数 (ff) 相当低（<0.05）低于平衡值，表明从空气到土壤的沉积和净传输占主导地位。土壤-空气分配研究表明，辛醇-空气分配系数 (K) 和黑碳分配系数 (K) 都不是土壤有机质 (SOM) 的合适替代物，因此 SOM 的吸收在 HFR 的分配中没有或几乎没有作用。
