多溴联苯醚及其环境行为

多溴联苯醚(PBDEs)在环境中的浓度快速增长,在各种生物体和人体中也发现了PBDEs的存在,因此已经成为了全球性的环境污染物,是目前研究的一大热点。文章介绍了PBDEs的物理化学性质、分析方法、在环境中的分布归趋和控制措施,着重介绍了水环境中PBDEs的分布和归趋。     

新制和老化微塑料对多溴联苯醚的吸附

以2,2′,4,4′-四溴联苯醚(BDE-47)为多溴联苯醚(PBDEs)代表化合物,研究了新制和紫外光照射老化的聚乙烯(PE)和聚苯乙烯(PS)微塑料对BDE-47的吸附动力学和等温吸附,分析了盐度和溶解性有机质等环境因素对其吸附的影响,采用扫描电镜、 X射线衍线和全反射红外光谱对新制和老化微塑料进行了表征,探讨了新制和老化微塑料对PBDEs的吸附机制.结果表明,新制与老化PE的主要吸附模式为表面吸附和外液膜扩散,新制与老化PS主要受表面吸附影响.Freudlich模型的拟合度最好,表明微塑料对于BDE-47的吸附均表现为多相多层的不均匀吸附过程.BDE-47在新制PE、老化PE、新制PS和老化PS上的平衡吸附量分别为3.72、 3.76、 6.04和3.46 ng·g^-1.老化PE与新制PE相比,其平衡吸附量没有变化;但老化PS与新制PS相比,平衡吸附量降低了42.38%.外液膜扩散的分配作用是影响PE吸附的主要机制.与新制PS相比,结晶度和表面含氧官能团的增加,导致老化PS平衡吸附量降低.盐度对BDE-47在新制和老化微塑料上的吸附影响不大,但溶解性有机质的...     

Role of sorbent surface functionalities and microporosity in 2,2’,4,4’-tetrabromodiphenyl ether sorption onto biochars

The study provides insight into the combined effect of sorbent surface functionalities and microporosity on2,2 ′,4,4 ′-tetrabromodiphenyl ether (BDE-47) sorption onto biochars. A series of biochars prepared underdifferent conditionswere used to test their sorption behaviorswith BDE-47. The extents of sorption behaviorswere parameterized in terms of the single-point adsorption equilibrium constant (Koc ) at three equilibrium concentration (C e ) levels (0.001Sw (solubility), 0.005Sw , and 0.05Sw )whichwasdetermined using the Freundlich model. To elucidate the concentration-dependentdominant mechanisms for BDE-47 sorption onto biochars, K ocwas correlatedwith four major parameters using multiple parameter linear analysis accompaniedwith significance testing. The results indicated that at low concentration (Ce = 0.001Sw ), the surface microporosity term,which represented a pore-filling mechanism, contributed significantly to this relationship,while as concentrationwas increased to higher levels, surface functionality related to surface adsorption began to take thedominant role,whichwas further confirmed by the results of Polanyi-based modeling. Given the above results, adual mode model based on Dubinin-Radushkevich andde Boer-Zwikker equationswas adopted to quantitatively assess the changes of significance of surface adsorption aswell as that of pore fillingwith sorption processdevelopment. In addition, UV spectra of four typical aromatic compoundswhich represented the key structural fragments of biochars before and after interactionswith BDE-47were analyzed todetermine the active functional groups and supply complementary evidence for thedominant interaction force for surface adsorption, based onwhich π-π electron-donor-acceptor interactionwas proposed to contribute greatly to surface adsorption.     

应用环境多介质逸度模型研究废旧电器拆解区多溴联苯醚的迁移及归趋

利用Level(Ⅲ)逸度模型模拟了浙东某废旧电器拆解区域多溴联苯醚(PBDEs)3种同系物在大气、水体、土壤和沉积物中的分布及迁移通量.在稳态假设条件下3种PBDEs同系物在环境介质中浓度的模型模拟值与实测值吻合较好,验证了模型的可靠性,通过参数灵敏度分析表明PBDEs的基本性质如蒸气压、正辛醇/水分配系数、在介质中的半衰期是影响化合物在环境相中浓度分布的主要因素.研究发现,在废旧电器拆解区大气中PBDEs对下风向的地区可能造成一定程度的污染;当环境系统达到平衡时,在废旧电器拆解区PBDEs主要蓄积在土壤和沉积物中,占所有环境介质中PBDEs的95%以上,土壤和沉积物是PBDEs污染的重要二次污染源;PBDEs在介质间的迁移以大气-土壤和水体-沉积物途径为主;废旧电器拆解区土壤中降解是PBDEs在环境中消减最主要途径.研究结果将为废旧电器拆解区PBDEs污染的风险评估和控制提供依据.     

我国典型电子废弃物拆解地农田土壤中的多溴联苯醚

选择我国主要电子垃圾拆解地清远龙塘-石角地区作为研究区,以14种多溴联苯醚(Polybrominated Diphenyl Ethers,PBDEs)化合物为研究对象,探讨了PBDEs化合物在龙塘-石角地区农田土壤中的含量、同系物组成及空间分布状况,分析了土壤TOC、土地利用方式(水旱轮作)等对农田土壤PBDEs含量特征的影响.结果表明,清远龙塘-石角地区农田土壤中14种PBDEs化合物的总量平均为(19.0±20.1)ng·g-1(以干重计),明显低于来自路边、拆解中心、居民区等表土中的PBDEs含量.研究区农田土壤中PBDEs的空间分布与土壤TOC呈现出一致性特征,当去除TOC的影响后,作为点源的电子垃圾拆解地成为土壤PBDEs分布的关键控制因素.水旱轮作的土地利用方式下,在一个轮作周期内,当轮作为水稻且土壤处于淹水状态时土壤中的PBDEs含量最低.总体来看,农田土壤中的PBDEs动态受土壤水含量、作物种植情况、土壤水旱状态等多因素的综合影响,表现出不确定的变化特征.本文的研究成果对土壤-作物系统PBDEs的行为研究进行了补充,并可为完善现有的土地质量评估体系提供基础资料.     

长江口围填海土壤中PBDEs的浓度、组成及来源解析

选取上海市崇明岛为采样区域,研究1974—2010年5个年代的由长江泥沙冲刷淤积而成的长江口围填海土壤中PBDEs的质量比分布、组成特征,并对其进行来源解析。于2012年10月在选取的5个年代区域分别采用五点梅花网格布点法采集表层(0~15 cm)和深层(100 cm)土壤,样品经索氏提取和层析净化处理后,采用GC-MS定量定性方法检测。结果表明,12种PBDEs目标化合物全部被检出,表层和深层土壤中∑12PBDEs质量比范围分别为8.008~27.783 ng/g、7.032~12.506 ng/g,主要是低溴代PBDEs。此外,其污染水平随年代呈现不断上升的趋势。最后基于因子分析法解析其来源,围填海土壤样品中最主要的污染源是PBDE-17、47、66和28;而且结合土壤污染质量比及组分特征分析得到,表层土壤与下一年代的围填海深层土壤的污染水平和来源基本一致。     

环境中多溴联苯醚污染状况调查及其对人体健康的影响研究

多溴联苯醚（ PBDEs ）作为阻燃剂在日常生活中被广泛应用。 PBDEs是一种新增的环境持久性有机污染物,在环境中不易降解,且具有亲脂性、生物富集性和生物毒性,并能通过多种传输途径在全球范围内迁移,所造成的环境问题已成为目前环境科学研究的热点。针对该问题,综述了近些年环境中PBDEs的污染研究进展,分析空气、水与日常食物中PBDEs的污染水平,对人体PBDEs暴露的途径以及环境中PBDEs污染对人类健康产生的影响进行了总结。并且对目前存在的问题以及进一步的研究方向进行讨论和展望,提出应加强对环境中PBDEs污染的调查研究,开展人体PBDEs暴露的潜在风险评估,为保证居民健康提供科学依据。     

Polybrominated diphenyl ethers and persistent organochlorines in Japanese human adipose tissues

The present study determined concentrations of polybrominated diphenyl ethers (PBDEs) and persistent organochlorines (OCs) in Japanese human adipose tissues collected during 2003–2004. Concentrations of PBDEs in adipose tissues were 1–2 orders of magnitude lower than those of OCs. However, observed PBDE congener levels in this study were relatively higher than those in Japanese human adipose tissues collected during 2000 reported previously, while OC levels were comparable to those in specimens collected during 1999 reported by our group. In addition, no age-dependent accumulation of PBDEs was observed, while OC levels except chlordane compounds increased with age. These results indicate recent human exposure to PBDEs in Japan. Among PBDE congeners accumulated in Japanese adipose tissues, BDE-153 was dominant, but this trend was different from those in human milk (BDE-47) and blood (BDE-209) reported previously in Japan, implying the congener-specific kinetics in human bodies. The significant positive correlations between PBDEs and OCs were observed in Japanese adipose tissues, indicating the similar exposure route of these contaminants for Japanese citizens, probably via fish intake.     

Bioaccumulation and trophic transfer of polybrominated diphenyl ethers (PBDEs) in biota from the Pearl River Estuary, South China

Two hundred and fifty-four biota samples (four species of invertebrates and ten species of fish) were collected from the Pearl River Estuary between 2005 and 2007 and one hundred and twenty four individual or composite samples were analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of PBDEs in organisms varied from 6.2 to 208 ng/g lipid weight. This PBDE level was significantly lower than those collected in 2004, showing a decreasing trend of PBDEs in biota in the study area. Trophic magnification factors (TMFs) for nine BDE congeners were calculated with values ranging from 0.78 to 3.0. TMFs of BDE47, 66, 100, 99, 154, and 153 were statistically greater than one, indicating a biomagnifcation potential for these congeners. Significant positive correlations were also found between concentrations of the total PBDEs, BDE28, 47, 66, 100, 99, 154, and153 and lipid content in biota, indicating the that bioconcentration also played an important role in the accumulation of PBDEs. No correlation between trophic level and lipid content was found, suggesting that biomagnification was not the result of lipid content effect but indeed occurred. The concentration ratios of BDE99 to BDE100 were much lower in biota than that in water implying that potential congener-specific biotransformation of PBDEs occurred and influenced the biomagnification of BDE congeners.     

"Novel" brominated flame retardants in Belgian and UK indoor dust: implications for human exposure

Concentrations of several “novel” brominated flame retardants (NBFRs) are reported in indoor dust samples from Belgian houses (n = 39) and offices (n = 6) and from day-care centers and schools in the West Midlands of the UK (n = 36). Using a GC-ECNI/MS method, the following NBFRs were quantified: decabromodiphenyl ethane (DBDPE) (range <20-2470 ng g⁻¹), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) (range <0.5-1740 ng g⁻¹), tetrabromobisphenol A-bis(2,3-dibromopropylether) (TBBPA-DBPE) (range <20-9960 ng g⁻¹), 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB) (range <2-436 ng g⁻¹) and bis(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (TBPH) (range <2-6175 ng g⁻¹). Hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO), another NBFR, was below the detection limit of 2 ng g⁻¹ dust in all dust samples. No correlation was detected between concentrations of NBFRs and PBDEs. The ratio of TBB:TBPH in the dust samples ranged from 0.01 to 4.77 (average 0.42), compared to the ratio present in the commercial flame retardant product FM 550 (TBB:TBPH = 4:1). Furthermore, no correlation was detected between concentrations in dust of TBB and TBPH. This may suggest different sources of these NBFRs, or similar sources but compound-specific differences in their indoor fate and transport. Exposure via dust ingestion was estimated for both adults and toddlers under low-end (5th percentile), typical (median), and high-end (95th percentile concentrations) scenarios. These were calculated assuming 100% absorption of intake dust and using mean dust ingestion (adults = 20 mg d⁻¹; for toddlers = 50 mg d⁻¹) and high dust ingestion (adults = 50 mg d⁻¹; for toddlers = 200 mg d⁻¹). Typical exposure with high dust ingestion estimates for adults were 0.01, 0.2, 0.01, 0.02 and 0.08 ng kg⁻¹ bw d⁻¹ and for toddlers 0.05, 1.9, 0.08, 0.4 and 1.12 ng kg⁻¹ bw d⁻¹ for BTBPE, DBDPE, TBB, TBPH and TBBPA-DBPE, respectively. Our results showed that, similar to PBDEs, toddlers have higher exposure to NBFRs than adults. This study documents the presence of NBFRs in indoor environments, and emphasizes the need to evaluate the health implications of exposure to such chemicals.