环境磁学在重金属污染研究中的应用

20世纪60年代以来,环境磁学以快速、灵敏、经济、无破坏性和信息量大等特点被广泛应用到环境污染研究中。笔者介绍了环境磁学应用于重金属污染监测的基本原理和优势,系统综述了其在大气,水体(湖泊、河流和海岸等)和土壤等环境重金属污染监测中的主要成果和最新进展,包括磁学参数可作为重金属污染物质代用指标,以及环境磁学在重金属污染分布特点和污染程度鉴定、重金属污染历史重建、重金属污染物运移追踪等方面的应用。提出了重金属污染磁性诊断研究还需要解决的问题,包括磁学参数多解性,其他环境过程(动力分选、吸附解吸和早期成岩等)的干扰和影响,磁性矿物与重金属物质赋存关系及多学科交叉研究等。     

城市环境中磁学响应的研究进展

利用磁学方法研究城市环境中重金属元素的污染受到普遍关注和重视。比较系统地探讨了城市环境中磁性矿物的来源和特征,阐述了城市环境磁学的研究内容,探讨了城市磁学研究的发展趋势,强调了运用简便、经济的磁学方法研究城市环境中重金属等污染物是今后环境磁学的一个重要的发展方向。     

成都市地表灰尘重金属污染分布特征及健康风险评价

对成都市中心城区娱乐区、居民区、商业区和城市广场等日常活动区域代表点的地表灰尘中的重金属进行监测,分析其污染分布特征,并应用美国EPA人体暴露风险评价方法对地表灰尘进行了健康风险评价。结果表明,研究区域地表灰尘重金属污染较为严重,Pb、Zn、Cu、Ni、Cr、Cd的平均含量分别为成都市土壤背景值的1.18~77.57倍,其中Cd的富集因子大于10,污染极强且富集在颗粒物中。暴露模型计算表明,重金属慢性每日平均暴露量为手-口摄入量皮肤吸收量吸入空气量,经手-口接触行为是人体地表灰尘暴露风险的主要途径。儿童重金属非致癌风险CrPbCdCuZnNi,成人重金属非致癌风险PbCrCdCuZnNi,且均小于非致癌风险阈值1,不会对城市人群造成明显伤害。重金属致癌风险CrCdNi,均低于致癌风险阈值,表明不具有致癌风险,但潜在生态危害值得重视。     

基于BM和PMF模型的库尔勒市地表灰尘重金属来源解析

在新疆库尔勒市采集54个代表性地表灰尘样品,分析其中Hg、Cd、As、Pb、Cr和Cu 等6种元素含量。采用重心模型（BM模型）和正矩阵分解模型（PMF模型）,分析地表灰尘重金属元素主要来源。结果表明：库尔勒市地表灰尘中Hg、Cd、As、Pb、Cr和Cu等元素的含量重心均偏离几何中心,地表灰尘中重金属元素含量分布存在不均衡性。研究区地表灰尘中Hg和Pb受到工业、交通来源及煤炭燃烧等混合污染源的影响,As受到成土母质的影响,Cd、Cr和Cu主要受到交通排放的影响。BM模型在确定地表灰尘重金属污染来源研究上有一定的应用前景。     

昆明市湿地公园地表灰尘重金属污染特征及健康风险评价

城市湿地公园是人们休闲娱乐的重要场所,但其地表灰尘的人群暴露健康风险却鲜有报道。该研究收集昆明市3个最受欢迎的湿地公园景区地表灰尘样品,利用等离子发射光谱仪(ICP-OES)测定灰尘中Pb、Cd、Hg、As、Zn、Cr、Cu、Ni、Co、Mn含量,使用地累积指数法(I_geo)、污染负荷指数法(PLI)和潜在生态风险指数法(RI)探讨湿地公园灰尘重金属污染特征,借助美国环保署健康风险评价模型,开展成人和儿童的重金属健康风险评价。结果表明：灰尘中10种重金属平均含量均超昆明市土壤背景值,其中Cd、Hg和Zn平均含量超背景值6倍,Cr、Ni、Co的I_geo<1。污染负荷指数法结果显示Hg、Cd、Zn中度污染,Pb、Cu和As则具有中等以上生态风险。人体健康风险评价结果显示,经口摄入为重金属主要暴露途径,其次是皮肤直接接触和呼吸吸入。Ni、As、Cd、Co和Cr的致癌风险值均小于10^-6,但若长期处于此种环境,可能会存在潜在的致癌风险。对于非致癌元素而言,Pb、Zn、Cu、Mn非致癌健康风险值都远小于1,即风险可以忽略。     

城市土壤重金属污染及其生态环境效应

对城市土壤中重金属的来源、空间分布特征、化学形态、在不同介质间的迁移转化及其污染的生态环境效应等近年来的研究进展进行了回顾,指出今后的研究重点是建立城市土壤重金属污染风险评价和标准体系,并应对重金属在城市环境中的迁移转化机制及城市土壤质量演变与郊区之间的关系开展研究。     

城市土壤重金属污染研究现状及问题

城市土壤重金属污染是城市土壤研究的一个重要方面，在阐明城市土壤研究历史的基础上，分别从重金属污染的空间分异研究和重金属污染的环境效应研究两个方面分析了城市土壤重金属污染的国内外进展，并指出了当前存在的问题与今后研究的方向。     

城市土壤重金属污染研究现状与趋势

阐述了城市土壤重金属的主要来源、空间分布特征、化学形态与影响因素,以及对人体的健康风险与生物效应,指出今后的研究重点与趋势是建立城市土壤重金属污染概念和标准体系,研究其在环境中的迁移转化机制与规律及城市土壤重金属复合污染,发展判源分析新技术.     

环境地球物理在污染场地调查中的现状及展望

简述了国内外对不同污染场地调查环境地球物理方法的研究现状及成果,指出了目前存在的问题.针对污染场地调查污染深度浅、污染浓度低的特点,提出了建立重金属污染在浅层迁移的数学物理模型和提高设备检测精度的必要性.对环境地球物理方法在环境领域的应用进行了展望.     

徐州市地表水体底泥重金属污染特征研究

文章对徐州市地表水体底泥重金属的污染特征进行了研究。对流经徐州市的四条主要河流和云龙湖的55个底泥采样点的重金属含量进行了测试,并采用单因子污染指数法进行了评价。结果表明,徐州市地表水体除云龙湖之外均不同程度地受到了重金属元素的污染。荆马河污染最为严重,其次是奎河、故黄河、京杭大运河。云龙湖的第五个采样点也受到了Hg的污染。污染元素的种类及污染程度与徐州市的产业结构密切相关。     

Magnetic properties of the road dusts from two parks in Wuhan city, China: implications for mapping urban environment

Magnetic parameters and heavy metal concentrations of road dusts collected from two parks with distance about 16 km in Wuhan city, China, were measured. The Guishan Park is circled by main roads with heavy traffic, and the Moshan Park is located on the downwind hills of steelworks and a power plant. Mean values of magnetic susceptibility (??) and saturation magnetization (M _s) of the dusts from the Moshan Park are 1.31 and 1.57 times those from the Guishan Park, respectively. Their magnetic mineralogy is dominated by pseudo-single domain magnetite; however, minor hematite was also identified in those from the Guishan Park. The dominant sources of non-natural magnetic particles and heavy metals were inferred as windblown emissions from the steelworks and the power plant for the Moshan Park, and road/railway traffics for the Guishan Park, respectively. Spatial variation in magnetic properties of road dust in the two parks and their different magnetic behavior propose that the magnetic measurements are sensitive to the different pollutant origins, as well as the urban environment, and that magnetic techniques have a high efficiency in mapping urban environment. Correlation between magnetic parameters and heavy metal concentrations is strongly site-specific: strong correlations were observed in the Moshan Park with correlation coefficients generally higher than 0.800, whereas correlations are poor in the Guishan Park. Therefore, it is strongly recommended that these relationships should be examined thoroughly before magnetic mapping.     

Heavy metal contents and magnetic susceptibility of soils along an urban–rural gradient in rapidly growing city of eastern China

The accumulation of heavy metals (Cd, Cr, Cu, Pb and Zn) and magnetic minerals in soils along an urban-rural gradient in the rapidly growing Hangzhou City, Eastern China, was measured. The analytical results indicated that heavy metal concentrations, magnetic susceptibility (chilf) and saturation isothermal remnant magnetization (SIRM) in soils decreased with increasing distance from the urban center. The significant relationships existed between heavy metal concentrations, chilf and SIRM and distance from the urban center. The soils in the urban areas were enriched with Cd, Cu, Pb and Zn. Elevated concentrations of heavy metals (especially Cd and Zn) in urban areas indicated the evidence for the accumulation of heavy metal contaminants from anthropogenic activities. Enhanced heavy metal concentrations and magnetic susceptibility were located in the uppermost soil horizons (0-10 cm), decreasing downwards to background values. The significant positive correlations between the Tomlinson Pollution Load Index (PLI) and magnetic susceptibility and SIRM were observed in polluted soil samples. Strong positive correlation indicated that magnetic screening/monitoring provided a fast and non-destructive tool, which can be effectively used as a proxy to detect environmental pollution in rapidly growing urbanization regions affected by anthropogenic activities.     

Impacts of Traffic-Induced Lead Emissions on Air, Soil and Blood Lead Levels in Beirut

Lead is a purely toxic heavy metal which induces a wide variety of adverse physiologic effects. Nevertheless, it has been mined and used for more than 8,000 years. Among the different contemporary sources of lead pollution, traffic-induced emissions from the combustion of leaded gasoline is of particular concern, as it can constitute more than 90 percent of total lead emissions into the atmosphere in congested urban areas where no phase-out activities have been adopted. Gasoline lead content and traffic volume are strongly correlated with concentrations of lead in various environmental media. In the absence of policies to reduce the use of lead in gasoline or to favor the use of unleaded gasoline, leaded gasoline remains the predominant grade in many countries. This paper assesses the status of lead pollution from the combustion of leaded gasoline in Beirut based on field measurements of lead in air and roadside dust of urban and rural/suburban areas and recent data on soil and blood lead levels. Average atmospheric lead concentrations was about 1.86 microg m(-3) at urban locations and 0.147 microg m(-3) at suburban locations. The analysis of roadside dust revealed an average lead level of 353 microg g(-1) along urban streets and 125 microg g(-1) along rural/suburban roads. Blood lead levels were also relatively high in comparison to countries where leaded gasoline has been phased-out.     

上海市降尘自动监测系统研发与应用

大气降尘量是重要的环境指标之一,可以较客观地反映和评价城市局部地区扬尘污染水平,对评价城市区域环境空气质量、分析大气污染来源和变化具有重要意义。国内外大气降尘监测普遍采用传统的手工监测方法,手工法因时效性差、效率低、能耗大、质控难、误差大等原因已不适应现代环境管理的需求。随着科技与网络的发展,自动监测方法成为发展趋势。文章主要阐述了上海市降尘自动监测技术的研发过程及实际应用,介绍了自主研发的降尘自动监测仪的原理、关键技术和系统组成。通过粉尘舱内实验、降尘自动监测方法与手工重量法比对测试及为期一年的试点应用,分析了降尘自动监测方法的精密度、准确度、相对误差及适用性,并探讨了降尘自动监测的应用前景。     

Impact of overland traffic on heavy metal levels in highway dust and soils of Istanbul, Turkey

The purpose of this study was to investigate the impact of overland traffic on the spatial distribution of heavy metals in urban soils (Istanbul, Turkey). Road dust, surface, and subsurface soil samples were collected from a total of 41 locations along highways with dense traffic and secondary roads with lower traffic and analyzed for lead (Pb), zinc (Zn), and copper (Cu) concentrations. Statistical evaluation of the heavy metal concentrations observed along highways and along the secondary roads showed that the data were bimodally distributed. The maximum observed Pb, Zn, and Cu concentrations were 1,573, 522 and 136 mg/kg, respectively, in surface soils along highways and 99.3, 156, and 38.1 mg/kg along secondary roads. Correlation analysis of the metal concentrations in road dust, surface and 20-cm depth soils suggests the presence of a common pollution source. However, metal concentrations in the deeper soils were substantially lower than those observed at the surface, indicating low mobility of heavy metals, especially for Pb and Zn. A modified kriging approach that honors the bimodality of the data was used to estimate the spatial distribution of the surface concentrations of metals, and to identify hotspots. Results indicate that despite the presence of some industrial zones within the study area, traffic is the main heavy metal pollution source.     

南京市重金属污染综合防治管理经验初探

分析了目前重金属污染综合防治管理的现状及存在的问题,介绍了"十二五"期间南京市重金属污染综合防治管理经验。指出明确的重金属污染物减量化目标、系统的管理模式设计和科学的政策手段是该市重金属污染综合防治取得成效的关键,包括采取的主要干系人协调合作模式,以及加强组织领导、强化污染源头控制、落实企业主体责任、防范场地环境污染、提升环境监管能力、加强制度标准建设等政策手段,并对今后的工作方向提出了具体建议。     

南京市城区环境空气中总悬浮颗粒物的源解析

应用受体模式的化学质量平衡法（ＣＭＢ），对南京市城区７个环境监测点环境空气中的总悬浮颗粒物（ＴＳＰ）进行污染源的源解析，得出４类主要污染源对ＴＳＰ的平均贡献率，建筑尘３９．８％、煤烟尘２５．７％，土壤尘１９．２％，冶炼尘１．８％，同时，对该市城区的地面尘也进行了源解析，表明地面尘与环境中ＴＳＰ的构成相近。