【作者】 刘玲；

【导师】 方炎明；

【作者基本信息】 南京林业大学 ， 植物学， 2013， 博士

【摘要】 随着城市工业化的快速发展以及城市人口、机动车数量快速增长，城市空气污染日益加剧，首要大气污染物已从气体转变为空气悬浮颗粒物（PM），高浓度的空气动力学直径小于或等于10μm和2.5μm的悬浮颗粒(PM₁₀、PM_2.5)及其吸附的重金属（如Cd、Cr、Cu、Ni、Pb和Zn等）严重影响人体健康，监测环境可吸入颗粒浓度和重金属含量已成为环境保护工作的基础任务，植物监测又为环境污染分析提供了一条便捷而有效的途径，城市树木叶片已经被用于众多的空气重金属污染研究中。本研究对淮南市空气可吸入颗粒的理化特征及不同环境可吸入颗粒的来源进行了分析，验证了不同环境PM日平均质量浓度、重金属含量和悬铃木叶片重金属累积值的动态变化及相关性，比较了淮南市常见7种行道树对空气颗粒的吸附、重金属的累积和对交通污染的生理响应，并选择广布树种悬铃木分析了淮南市空气重金属污染格局。主要研究结果如下：（1）在淮南市六区一县选择了6个有代表性的采样点，采集一年大气PM₁₀和PM_2.5样品。利用分析天平、电感耦合等离子发射光谱仪（ICP-OES）等分析研究了大气颗粒物的理化特征及其来源。结果显示，淮南市大气颗粒物污染水平具有明显的季节和空间变化：冬季和春季污染重，夏季污染最轻；不同采样点PM₁₀和PM_2.5质量浓度和粗细颗粒比例、所含元素的浓度及主导元素种类也有差别，18种元素中富集因子大于10的有Cd、Cr、Cu、Ni、Pb、Zn等6种重金属；颗粒物所含元素在细粒子中的富集程度高于粗粒子。PM₁₀和PM_2.5主要来自煤炭燃烧、交通车辆带动的路尘和排放的尾气。（2）在淮南市选择矿区（潘集）和清洁区（淮南师范学院）作为采样点，比较了不同环境的总悬浮颗粒物（TSP）、PM₁₀、PM_2.5的日变化和采样期的日平均质量浓度及重金属含量的差异，分析了不同粒径悬浮颗粒和颗粒富集重金属量与悬铃木Platanus acerifolia叶片累积的重金属的相关性，结果表明，淮南市矿区大气处于较严重的污染状况，TSP、PM₁₀、PM_2.5的日平均质量浓度在采样期间有半数以上超标，大气颗粒中主要的重金属是Zn和Pb，PM_2.5占大气悬浮颗粒的大部分，重金属含量主要与粗颗粒呈正相关。矿区悬铃木叶片累积重金属量大于清洁区，叶片累积重金属与大气环境中含有的重金属呈正相关，环境污染越严重，正相关性越高，叶片累积6种重金属的量与大气PM_2.5的质量浓度都成正相关。（3）在淮南市交通繁忙点选择银杏Ginkgo biloba等7种树木进行试验,分析了叶片吸附不同粒径空气悬浮颗粒的百分率、单位叶面积吸附不同粒径颗粒的质量与叶片微形态的关系和单位叶面积不同粒径颗粒吸附量与重金属累积量的相关性。结果表明，叶片面积小、表皮角质丰富和细胞壁凸凹不平、无表皮毛阻挡、气孔密、气孔口大的树木，属气孔吸附主导型，主要吸附细颗粒物；表皮毛多的树木，属表皮吸附主导型，主要吸附粗颗粒物。7种树木叶片累积重金属除铅外都具显著差异，其中银杏、女贞Ligustrum lucidum、香樟Cinnamomum camphora对重金属的累积能力较强；悬铃木吸附粗颗粒和累积Pb多于其他树种；7种树木叶片对Cd、Cr、 Ni、Zn、Cu这5种重金属及总含量的累积与单位面积吸附的可吸入颗粒量呈正相关，d10与d2.5、d10与d1.0、d2.5与d1.0的相关系数分别是0.987、0.971、0.996，达到极显著水平，d2.5/d10、d1.0/d10、d1.0/d2.5的值分别是0.844、0.763、0.822,表明由交通污染产生的颗粒物主要是细颗粒物。（4）为了筛选适合交通污染监测的树种，对淮南市交通主干道7个树种叶片中的重金属（Cd、Cr、 Cu、Ni、Pb、Cd）含量和生理指标丙二醛（MDA）、可溶性糖、超氧化物歧化酶（SOD）变化进行了分析，结果表明：交通要道重金属含量显著高于森林公园稀疏交通区，交通污染的影响显著；在丙二醛、可溶性糖、SOD含量方面，交通主干道总体高于稀疏交通区，这可能是对交通污染的响应。根据生理指标和重金属变化幅度及重金属累积量的相对差异百分比对其进行功能型的划分确定香樟、女贞、悬铃木和银杏适合交通污染监测。（5）选择单位面积吸附颗粒量多，对环境污染的生理调解能力较强的广布树种悬铃木为实验树种，对2012年8月淮南市42个样区悬铃木叶片累积的6种重金属进行测试，利用类平均法和克里克值进行42个样区聚类和空间分析。结果表明，淮南市各个样点按照重金属污染的程度分为3个样点组，与环境污染程度有一定关系。地理信息系统（GIS）分析图谱显示淮南市有一条西南-东北走向的重金属重度污染带,6种重金属元素累积量基本维持“市中心高，郊区偏低”、“重工业区高，纯自然村低”的趋势，有煤矿、电厂分布及交通流量大的区域污染较重。更多还原

【Abstract】 With a sharp increase in industrial activities, urban population, and city vehicles, air pollution inurban became serious. The first airborne pollutant transferred from SO2to particulate matter（PM）. The adverse effects on human health due to inhalation of PM₁₀and PM_2.5, as well as heavymetals contained in PM such as cadmium, lead, chromium, copper, nickel, and zinc have beenidentified. It is primary work to monitor concentration of inhalable particles and heavy metals inenvironmemtal practice. Assessment of environmental pollution by plants has been proved to bea convenient method of pollutant analysis. And tree leaves have been used as bioindicators ofatmosphere heavy metal pollutants in numerous studies. Physico-chemical characteristics andemission sources of inhalable particles were analyzed in Huainan, Anhui, China. Correlationamong daily average mass concentration of PM, content of heavy metals in PM, and content ofheavy metals accumulated in leaves of Platanus acerifolia was investigated in this study.Variation in PM absorption and metal accumulation and physiology response to traffic pollutionwas documented for leaves from seven tree species. A spatial pattern in distributions of heavymetal pollution indicated by P. in Huainan was recognized in this paper. The main results are asfollows:（1） PM₁₀and PM_2.5samples were collected at six sites accounting for major environmentalfeatures in Huainan during one year. Various approaches, such as Analytical Balance andInductively Coupled Plasma Optical Emission Spectrometer, were used to analyzephysico-chemical characteristics and sources of airborne particles. The results indicaed aremarkable pattern of spatial-temporal variation in pollution levels of PM₁₀and PM_2.5. PMconcentrations in winter and spring were much higher than the other seasons, and summer wasthe lowest season in PM concentrations. Significant difference were found among sample sites inmass concentration of PM₁₀and PM_2.5,ratios of fine to coarse PM, element concentrations in PM,and kinds of leading elements. Elements with higher enrich factors （EF＞10） were characterizedas Cd, Cr, Cu, Ni, Pb and Zn from18elements measured. EFs of elements in fine PM werehigher than those in coarse PM. The sources of PM₁₀and PM_2.5were coal burning, road dust andexhaust caused by vehicle.（2）Daily variation and daily mass concentrations of TSP, PM₁₀, PM_2.5and contents of heavymetals in TSP were compared between clean and polluted sites. Correlation among PM diameterdistributions, heavy metal contents in PM, and heavy metal contents in leaves of P. acerifoliawere analyzed respectively. The results revealed a rekarkbly high measurement in daily averageconcentration of TSP, PM₁₀, PM_2.5, within air-polluted coal-mine, with half data higher than thethreshold value in GB3095-2012. Zn and Pb were the dominant elements of heavy metals incoarse PM, while PM_2.5 was the main fraction of PM. Contents of heavy metals accumulated inleaves of P. acerifolia in coal-mine were higher than those in none coal-mine, positive correlationof heavy metal contents between TSP and leaves of P. acerifolia was found, indicating the highercorrelation coefficent the severer environmental pollution. Moreover, contents of six heavy metals in P. acerifolia were positivly correlated with mass concentrations in PM_2.5.（3）Seven tree species, such as Ginkgo biloba, at dense heavy traffic site in Huainan were selectedto analyze the effects of leaf micro-morphology on PM diameter frequency retained by leavesand particle amount of different sizes per unit leaf area,as well as relationship between particleamount of different sizes per unit leaf area and content of heavy metals. We found that thespecies characterized by small leaf area, special epidermis with abundant fax and highly unevencell wall, without trichomes as well as big and dense stomata mainly absorbed fine particulatematter; while those species with dense trichomes mainly retained coarse particulate matter.Accumulation of heavy metals in leaves of seven species was significantly different except Pb.Tree species with high capacities in heavy metal accumulation were G. biloba, Ligustrumlucidum, and Cinnamomum camphora. Accumulation of Cd, Cr, Ni, Zn, Cu and totalconcentrations of five elements were positively related to amount of particulate matter ofabsorption. Correlation coefficients of d10vs d2.5, d10vs d1.0, d2.5vs d1.0were0.987,0.971,and0.996respective, the correlation level were significant. The ratios of d2.5/d10, d1.0/d10,d1.0/d2.5were0.844,0.763, and0.822, thus particulate matter from traffic was mainly the finekind.（4） In order to select suitable species for transportation pollution monitoring, some representativetree species occurring in the arterial roads and the roads of a forest park in Huainan were chosento systematically study accumulation patterns in heavy metal elements （Cd, Cr, Cu, Ni, Pb andZn） and variation patterns in physiological indexes （MDA, souble sugar and SOD） in leaves bychemical analysis method and physiological index determination method. The results showedthat the heavy metal contents in the arterial roads were significantly greater than thos in the forestpark, which meaned transportation pollution was becoming more serious. Meanwhile, MDA,souble sugar and SOD levels on the arterial roads suffering from transportation pollution weremuch higher than forest park roads in general as well. According to the physiological indexes andheavy metal content differences, C. camphora, L. lucidum, P. acerifolia, and G. biloba arefounded as fine species for transportation pollution monitoring. Besides, their functional typeswere divided based on relatively difference percentage of tree species’ heavy metal content.（5） P. acerifolia planted in many sites of Huainan with strong PM-absorbing ability and goodphysioly-regulating capapcities were selected to analysis pollution paterns of heavy metals in42sampling sites, The relationship between the contents of heavy metals in the plants andenvironment factors were analyzed with average linkage cluster analysis method. The resultsindicated that the42monitoring sites could be divided into three groups with different degrees ofheavy metal pollution. GIS maps of the heavy metal contents were made. The map showed thatthere is a heavyly polluted belt in six heavy metals from SW-NE. The data of six heavy metals inP. acerifolia demonstrated a trend of heavy pollution in center, and light pollution in suburban ofHuainan. The sites with heavy pollution was in line with such areas as coal-mine, plant power,and heavy traffic.更多还原