| 题名 | 青藏高原等地区持久性有机污染物和新型污染物的环境行为研究 |
| 作者 | 朱娜丽 |
| 学位类别 | 博士 |
| 答辩日期 | 2013 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 江桂斌 |
| 关键词 | 持久性有机污染 persistent organic pollutants 青藏高原 Tibetan Plateau 环渤海地区 Chinese Bohai Sea 环境行为 environmental behavior 新型污染物 emerging contaminants |
| 其他题名 | Environmental behaviors of persistent organic pollutants and emerging contaminants in the Tibetan Plateau |
| 中文摘要 | 有机氯农药（OCPs）、多氯联苯（PCBs）、多溴联苯醚（PBDEs）和六溴环十二烷（HBCDs）是先后被列入斯德哥尔摩公约受控名单的持久性有机污染物（POPs）。它们具有高毒性，在环境中难降解，易于生物富集，且能够发生长距离迁移。除在污染源附近有高浓度检出外，它们能够在全世界范围内分布扩散，甚至到达高海拔和高纬度的偏远地区，从而影响全球生态环境系统。本论文对上述4类POPs在典型地区的污染现状、环境行为和长距离迁移机理展开了系统研究。 首先以青藏高原特别是植被覆盖较好的藏东南地区作为研究区域，通过系统采集大气、松萝和高山鱼类等环境及生物样品，研究OCPs、PCBs、PBDEs和HBCDs在高海拔环境中的污染水平及污染特征；通过探讨植被情况、有机质、季风及海拔梯度对目标化合物的影响，揭示了POPs在该地区的空间分布模式和可能的高山冷捕集及冷凝结效应机理。这部分的内容主要开展了以下3方面工作： 1．利用XAD-被动采样器技术，对藏东南色季拉山地区大气环境体系中POPs展开了深入研究。样品分析结果显示，α-硫丹(endosulfan I)、六氯苯、五氯苯、HCHs和DDTs是色季拉山大气环境中主要的POPs 污染物，而PBDEs和HBCDs浓度水平最低，处于背景值。由于夏季POPs具有较高的挥发速率，以及印度海洋季风所携带相对高浓度POPs的输入，使得藏东南地区目标化合物在夏季的浓度水平显著高于冬季浓度。由于地理位置、气候植被等条件的差异，色季拉山东坡大气样品中的POPs浓度水平和海拔梯度之间不存在显著相关性，然而西坡大气样品中DDTs及硫丹的浓度水平随海拔的升高而增加,且DDT浓度与海拔高度之间呈现显著正相关性，揭示DDT在青藏高原地区存在潜在的山地冷凝结效应。此外，研究结果表明森林内大气样品中POPs浓度高于森林外大气样品中的POPs浓度，一定程度上证明了藏东南地区森林过滤效应的存在。 2．对藏东南地区松萝样品中的POPs开展了监测分析。研究结果表明， endosulfan ?、4, 4'-DDT、2, 4'-DDT和α-HCH有较高含量检出。DDTs、endosulfan、PBDEs和HBCDs浓度水平与松萝脂质含量呈显著正相关。HCH、DDT、Endosulfan、PBDEs及PCBs的脂肪归一化浓度与海拔高度呈显著正相关，在一定程度上证明了上述POPs在高海拔地区的冷捕集/冷凝结效应。相关频率分布直方图和山体污染潜能模型（Mountain Contamination Potential Model）表明辛醇-空气分配系数（logKoa）及水-气分配系数（logKwa）在8-10 和2-4之间的半挥发性有机污染物较容易在高山环境中累积存在。和XAD数据对比表明，松萝可作为偏远地区大气环境中POPs的生物指示物。 3．对青藏高原地区3条河流（拉萨河、尼洋河、雅鲁藏布江）和4个湖泊（羊湖、青海湖、班公措、巴松措）中的野生鱼样进行了样品收集和数据分析，研究青藏高原鱼体中HBCDs的生物累计、空间分布及单体分布特征，获取西藏水体生态系统中HBCDs污染状况的第一手资料。研究结果表明，在79条野生鱼样的鱼肉组织中，HBCDs的检出率为65.8%，平均脂肪归一化浓度为2.12 ng/g lw。较高的检出率和浓度水平揭示青藏高原水体生物体内普遍存在着HBCDs污染。在HBCDs的3种单体组成中，α-HBCD是主要成分，占据总浓度的78.9%，而β-HBCD在所有样品中都未检出。HBCDs总浓度（干重浓度）与鱼体脂肪含量呈显著正相关性(R = 0.297, p < 0.05)。α-HBCD浓度随鱼营养级的升高而降低，但γ-HBCD浓度与鱼营养级之间没有明显相关性。此外，湖鱼体内HBCDs总浓度水平与采样点年降水量之间呈现显著正相关性，在一定程度上说明了西藏地区HBCD的远距离传输途径主要依赖于干/湿沉降。 除青藏高原外，本论文还选取了环渤海作为研究区域，通过对采集于该地区的软体动物体内的HBCDs、PBDEs以及新型污染物TBC的分析，系统研究了新型溴代阻燃剂在该地区的的浓度水平、空间分布以及历史演变趋势。研究结果表明，PBDEs、HBCDs和TBC在软体动物体内都有非常高的检出率，分别为100%、99%和77%。其对应的浓度水平分别为n.d.-28.8 ng g-1 dw，0.01 - 20.4 ng g-1 dw和n.d. - 12.1 ng g-1 dw。三者化合物之间存在显著相关性，且都和软体动物脂肪含量呈正相关。它们各自的浓度水平都随着软体动物营养级的升高而降低，表现出一定的营养级稀释效应。和其他11种软体动物相比，紫贻贝对上述三类化合物具有最高的生物富集性，结合于我们实验室之前在该地区的研究结果，紫贻贝被认为是表征环渤海地区持久性有机污染物的理想生物指示物。此外，研究发现从2003年至2010年，环渤海地区软体动物体内PBDEs的浓度水平呈显著下降趋势，其半衰期为2.3?1.7年，这一现象亦能说明软体动物对海洋环境中污染物的变化有较高的敏感性。 |
| 英文摘要 | Organochlorine pesticides (OCPs), polychlorinated biphenyl (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDs) are four typical persistent organic pollutants (POPs) listed into the Stockholm Convention because of their high toxicity, persistence in the environment, bioaccumulation through the food web, and potential of long-range transportation. They not only existed with high levels in the regions close to the sources but can also reach to pristine areas where they are never used or produced, such as high latitude or altitude regions, and pose a risk of causing adverse effects to humans and the ecosystem. This thesis focused on the environmental occurrence, behaviors and long-range transportation of OCPs, PCBs, PBDEs and HBCDs in the representative regions. Firstly this thesis investigated the levels of OCPs, PCBs, PBDEs, and HBCDs in air, lichen and alpine fish collected from the Tibetan Plateau, further to study the possible behaviors of target POPs under the influence of various environmental parameters i.e., vegetation, lipid, monsoon and altitude. It is expected that the study will give an insight of the source, atmospheric transport and cold-condensation effect of POPs in this high mountain area. This study includes three parts: 1. Basing on XAD-passive air samplers, the present work investigated a wide range of POPs in the air collected from Shergyla Mountain, southeastern Tibetan Plateau. Endosulfan ?, hexachlorobenzene, pentachlorobenzene, hexachlorocyclohexanes (HCHs) and dichlorodibenzotrichloroethane and its degradation products (DDTs) were the predominant compounds in air of the Shergyla Mountain while PBDEs and HBCDs showed the lowest background concentrations among the target contaminants. Most of the target POPs had significantly higher concentrations in summer than that in winter due to the enhanced volatilization rate and the higher level inputs by the Indian monsoon in summer. Generally, the concentrations of contaminants remained stable on the eastern slope of the Shergyla Mountain with altitudes whereas increasing trends of the concentrations of DDTs and endosulfan were found with increasing altitude on the western slope, implying the potential orographic cold-condensation in the sampling regions. Forest filter effect was also observed based on the lower air concentrations of the target POPs in the forest than the ones out of the forest. 2. The present study investigated a wide range of POPs in lichens (Usnea longissima Ach.) collected from the southeastern Tibetan Plateau, China. Endosulfan ?, 4, 4'-DDT, 2,4'-DDT and α-HCH were the predominant chemicals among the targeted compounds in the lichen samples. Generally, concentrations of DDTs, endosulfan, PBDEs and HBCDs showed significant correlations with the lipid contents of lichens. A clear concentration gradient with altitude was observed for the predominant compounds in lichen samples, implying the potential orographic cold-condensation in the Tibetan Plateau. Frequency distribution of the POPs, and the Mountain Contamination Potential (MCP) Model indicated that POPs with specific values of log KOA (8 - 11) and log KWA (2 - 4) had relative high mountain contamination potential. Usnea was considered to be the best choice of bioindicators for the POPs in the atmosphere of high mountain areas. 3. The present work studied the HBCDs in wild fish from 4 high mountain lakes and 3 rivers of the Tibetan Plateau. The purpose was to get the first work to widely explore HBCDs contamination in the aquatic ecosystems of the Tibetan Plateau. The ∑HBCDs in 79 fish muscles ranged from non detectable levels to 13.7 ng/g lipid weight (lw) (mean value of 2.12 ng/g lw) with a high detection frequency of 65.8%, which confirmed the wide occurrence of HBCD in the aquatic ecosystems of the Tibetan Plateau. α-HBCD dominated among the isomers and accounted for 78.2% of the total burden.Concentrations of ∑HBCDs in the fish were significan |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/35184]  |
| 专题 | 生态环境研究中心_环境化学与生态毒理学国家重点实验室 |
| 推荐引用方式 GB/T 7714 | 朱娜丽. 青藏高原等地区持久性有机污染物和新型污染物的环境行为研究[D]. 北京. 中国科学院研究生院. 2013. |
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