福建三明地区被污染土壤的磁学性质及其环境意义

对福建三明某钢铁厂和火电厂附近的污染表土样品进行了多参数的岩石磁学测试分析,包括χ T曲线、磁滞回线、等温剩磁获得曲线等. 三明地区污染表土中的磁性矿物有磁铁矿、赤铁矿和磁黄铁矿. 样品中磁性矿物的平均粒度较粗,为较大的准单畴,甚至多畴,粒度明显大于成土作用所产生的磁性颗粒. 粗粒的磁铁矿颗粒是污染物的主要磁性组分. 虽然磁化率测量可以作为一种简单、快速而且廉价的检测污染土壤的方法,但同时辅以必要的岩石磁学测量将有利于提取更多的污染信息. 对于低磁化率的污染土壤,亚铁磁性硫化物的存在可以作为土壤可能被污染的证据之一.     

中国北方城市大气降尘磁学特征及其环境意义

应用环境磁学方法研究了兰州市区及对照点大气自然降尘的磁学特征. 结果表明, 兰州市大气降尘中磁性矿物含量较高, 主要含有磁铁矿, 并伴有少量磁赤铁矿和赤铁矿, 磁性矿物为准单畴颗粒; 兰州市自然粉尘背景值较高, 但市区污染物以人为源为主, 尤其在冬季采暖期间; 在春、夏季节, 兰州市的污染仍以人为源为主, 与通常认为兰州市污染冬季以燃煤为主, 春、夏季以粉尘为主的模式有较大差异. 近年来, 兰州市空气污染防治已取得了一定成效, 空气质量有了较大改善, 冬季污染在逐年减轻, 而夏季污染变化不大. 环境磁学作为一种简单、快速且无破坏性的研究手段, 可以为城市污染源研究及城市污染防治研究提供许多极有价值的信息.     

天山黄土区与黄土高原表土磁性特征对比及环境意义

本文对黄土高原和天山黄土区表土进行系统的岩石磁学和粒度测试分析,探讨了表土磁性特征及其环境意义,结果表明表土中的强磁性矿物均为磁铁矿和磁赤铁矿,弱磁性矿物为赤铁矿和纤铁矿或针铁矿,黄土高原黄土地层中的磁赤铁矿至少有部分属于风积成因.黄土高原表土中磁化率与频率磁化率呈良好的正相关,气候作用是主导黄土高原表上磁化率增强的主...     

甘肃西山坪遗址岩石磁学性质及其研究意义探讨

对甘肃西山坪遗址剖面样品进行磁化率、频率磁化率、热磁分析、非磁滞剩磁和等温剩磁等一系列岩石磁学实验测试,分析环境磁学参数特征变化,试图探讨西山坪遗址研究意义,为今后深入研究该沉积序列蕴含的古环境记录提供了岩石磁学基础.结果表明：西山坪遗址剖面沉积物中磁性矿物主要以低矫顽力的磁铁矿和磁赤铁矿为主,高矫顽力磁性矿物赤铁矿含量极其有限,越向剖面表层,强磁性矿物含量逐渐增加.磁性矿物颗粒表现出黄土的典型特征,以单畴、准单畴为主,含有一定量的超顺磁颗粒,颗粒度越向剖面表层越细.从物源上看,遗址沉积物主要来自近源的黄土风尘堆积,主要是风成堆积,并混合大量人类活动信息,给今后综合研究岩石磁学与人类活动特征的关系有一定借鉴意义.     

杭州城区土壤的磁性与磁性矿物学及其环境意义

对杭州城区四个不同功能区块土壤进行了系统的环境磁学测定,结果表明城市土壤的磁化率平均值为128×10^-8m³·kg^-1,频率磁化率平均值3.6%(样品数=182),城市土壤呈现明显的磁性增强. 城市土壤的磁化率与频率磁化率呈极显著指数负相关,表明城市土壤磁性增强明显区别于自然成土过程引起的以超顺磁性(SP)颗粒为主的表土磁性增强机理. 统计分析表明,城市土壤磁化率与软剩磁和饱和等温剩磁(SIRM)呈显著直线正相关,说明亚铁磁性矿物是城市土壤剩余磁性的主要载体. 综合等温剩磁获得曲线、热磁曲线、磁滞回线等岩石磁学测定和SEM/EDX分析,城市土壤的磁性矿物以磁铁矿和赤铁矿为主,磁性矿物以假单畴-多畴（PSD-MD）颗粒存在,粒度明显大于成土过程形成的磁性颗粒,这些磁性颗粒主要来自燃料燃烧、汽车尾气等环境污染物. 因此,城市土壤磁测可作为城市土壤污染监测、污染空间分布和污染物来源判断的新手段.     

典型沙漠绿洲城市表土磁性特征及环境指示意义

选取典型沙漠绿洲城市（乌海、石嘴山、银川）表土为研究对象,对其环境磁学性质、土壤质地与重金属含量分布进行系统研究.结果表明,乌海市和石嘴山市表土为典型砂土,银川市为砂壤土.三个城市表土样品均以较粗的MD-PSD颗粒的亚铁磁性矿物（磁铁矿）为主导,磁化率均值分别为152×10^-8、104×10^-8和117×10^-8 m³·kg^-1.乌海市表土磁性矿物含量和磁性颗粒大小都显著高于石嘴山和银川市.重金属（Cr、Cu、Pb、Zn、Fe）的污染负荷指数（PLI）均显示,三个城市表土均存在轻度污染特征.同时磁化率和污染负荷指数在非工业区表现出点状高值分布,在工业区表现为面状高值分布特征.乌海市表土磁参数与重金属的相关系数显著高于石嘴山和银川,表明磁参数对于污染来源单一地区的污染程度评估更具优势.尽管三个城市表土磁学性质存在较大差异,但其磁化率均随污染负荷指数的增加呈现相同程度的递增.磁化率可以作为宁夏平原地区表土重金属污染程度评估的统一有效的代用指标.     

临汾市树叶磁性的时空变化特征及其对大气重金属污染的指示

粉煤灰经工厂废气排放进入大气,对人类健康和生态系统都造成了无法弥补的破坏.本文选取具有高空间分辨率优势的树叶作为收集粉煤灰的载体,对临汾市大气中可吸入颗粒物进行磁学参数和重金属含量监测.结果表明,磁化率最大值出现在工厂污染源附近,磁化率空间分布呈现随污染源距离增加而降低的趋势.工业区收集到的磁性颗粒以低矫顽力、粗粒度的磁铁矿为主.夏季磁性矿物来源单一,主要为人为影响.冬季大气中悬浮的磁性颗粒有部分来自于西北风/北风的自然尘降.同一采样点磁化率随时间变化特征表明,树叶的磁学性质可以灵敏和有效地反映较短时期内大气污染的现状.统计分析表明磁化率和重金属元素(铁,铬,镍,铜,铅,钴)之间存在显著相关性.污染负荷指数用于评估研究区域内重金属各元素综合污染的程度.结果显示,在废弃的旧工业区附近无大气污染指示,但在运营中的工厂集中的地区,大气均受到严重污染.污染负荷指数与表征磁性矿物含量的磁化率呈相关性(r2=0.66),因此树叶的磁性参数可以作为大气重金属污染的替代指标.     

钢铁厂周围不同污染介质的磁学性质及环境意义

为了通过钢铁厂周围不同污染介质的磁学性质研究,实现对环境污染的有效监测,本文系统地采集了河北兴隆和湖南娄底两个钢铁厂周围的树皮和草表面的飞灰、土壤及不同树种的年轮样品.其中前三者用来反映现今污染源,而树木年轮用来追踪长时间尺度的污染历史.通过综合岩石磁学实验分析（包括热磁曲线、磁滞性质和低温实验等）、电子扫描电镜(SEM)和能谱(EDX)以及X射线衍射(XRD)分析,发现钢铁厂周围现今污染源中的主要粗颗粒磁性矿物为磁铁矿、赤铁矿和纯铁.其中8~50 μm的球形磁铁矿颗粒和呈棱角状的铁颗粒是钢铁厂污染物的特征磁性矿物.对不同树种来说,其中香樟树和枫树树木年轮中的磁性矿物以顺磁性物质为主, 不适合用于环境磁学的污染监测.而柳树中的磁性矿物（主要为磁铁矿）与现今污染源的磁性矿物相符.以上研究表明多参数岩石磁学测量并辅以微观分析等手段,可以精确地提取磁性矿物的种类及粒度特征, 判别重工业区污染源,为应用磁学方法来监测环境污染提供依据.     

磁性矿物的磁学鉴别方法回顾

磁性矿物的组成和颗粒粒径的分布决定了岩石或沉积物的基本磁学性质及其所携带的天然剩磁在地质时期内的稳定性.由于自然界中磁性矿物的复杂性和多样性，如何有效的确定磁性矿物的成分和粒径分布一直是岩石磁学的基础和难点.本文对确定磁性矿物成分和粒径分布的常见方法进行了较为详细的总结和分析，并对常见磁性矿物在高温和低温下的磁学性质进行了详细的论述.最后对如何应用综合方法判定样品中的磁性矿物种类以及粒度分布进行了探讨.     

缅甸掸邦地块二叠纪-三叠纪灰岩的岩石磁学初步研究结果

对缅甸东部掸邦地块二叠纪-三叠纪灰岩样品进行了饱和等温剩磁获得曲线及反向场退磁曲线、三轴等温剩磁的系统热退磁、磁化率-温度曲线等岩石磁学测试分析,试图通过岩石磁学方法识别缅甸掸邦地块二叠纪和三叠纪灰岩样品中的磁性矿物种类、含量等信息,为研究样品中主要磁性矿物所携带的特征剩磁分量的磁化年龄等性质提高可靠的基础,从而为进一步研究掸邦地块及滇缅泰地块晚古生代-早中生代的古地理位置等提供有力的证据.结果表明缅甸掸邦地块二叠纪和三叠纪灰岩样品中的主要磁性矿物为磁铁矿,或磁铁矿和针铁矿的组合,少部分三叠纪灰岩样品显示有赤铁矿、磁赤铁矿和针铁矿的组合.     

Magnetic particles in indoor dust as marker of pollution emitted by different outside sources

The potential relation between outdoor pollutants and the quality of indoor air was evaluated. A case study was carried out in the small town of Zyrardow situated south-west of Warsaw, Poland. The indoor dust from 20 apartments from several parts of the town that are anticipated to be exposed to various levels of pollution was investigated: a mildly polluted area (suburban), a heating plant area, a post-industrial area and the city center. For evaluation of indoor dust several magnetic parameters (mass-specific magnetic susceptibility χ, its temperature dependence, anhysteretic remanent magnetization, hysteresis loop parameters) were applied. Analysis of magnetic properties was supplemented by analysis of chemical elements: Cd, Cu, Co, Cr, Fe, Mn, Ni, Pb and Zn. Depending on the location of apartments, large variations in concentration, mineralogy and grain-size of magnetic particles were detected. The thermomagnetic analysis revealed magnetite as a primary magnetic phase. In indoor dust, the Curie temperature of ~760°C and soft hysteresis loops with relatively low coercivity values of ~1.5-5 mT are an attribute of metallic iron. The dust collected from apartments located near the local heating plant area, in contaminated post-industrial and suburban areas contains mainly magnetite and only a small amount of metallic iron. Mass-specific magnetic susceptibility is in the range from 40 to 200 × 10^-8 m³kg^-1 and linearly correlates with concentration of individual heavy metals: Ni, Cr, Co and Zn. Magnetic fraction of dust from the city center mainly consists of magnetite and variable amounts of metallic iron. Magnetic susceptibility shows linear correlations with concentration of Fe and concentration of individual heavy metals (Zn, Ni and Co) considered as traffic-related. The study demonstrates that metallic iron present in indoor dust is a potential marker of trafficrelated sources and it makes it possible to use magnetic methods as a tool for evaluation of traffic-related impact on indoor air levels.     

Spatial character of the gaseous and particulate state compound correlation of urban atmospheric pollution in winter and summer

The spatial/temporal variation information of atmospheric dynamic-chemical processes at observation site points of the "canopy" boundary of Beijing urban building ensemble and over urban area "surface", as well as the seasonal correlation structure of the gaseous and particulate states of urban atmospheric pollution (UAP) and its seasonal conversion feature at observation points are investigated, using the comprehensive observation data of the Beijing City Air Pollution Observation Experiment (BECAPEX) in winter and summer 2003 with a "point-surface" combined research approach. By using "one dimension spatial empirical orthogonal function (EOF)" principal component analysis (PCA) mode, the seasonal change of gaseous and particulate states of atmospheric aerosols and the association feature of pollutant species under the background of the complicated structure of urban boundary layer (UBL) are analyzed. The comprehensive analyses of the principal components of particle concentrations,gaseous pollutant species, and meteorological conditions reveal the seasonal changes of the complex constituent and structure features of the gaseous and particulate states of UAP to further trace the impact feature of urban aerosol pollution surface sources and the seasonal difference of the component structure of UAP. Research results suggest that in the temporal evolution of the gaseous and particulate states of winter/summer UAP, NOx, CO, and SO2 showed an "in-phase" evolution feature, however, O3 showed an "inverse-phase" relation with other species,all possessing distinctive dependent feature. On the whole, summer concentrations of gaseous pollutants CO, SO2, and NOx were obviously lower than winter ones, especially, the reduction in CO concentration was most distinctive, and ones in SO2 and NOx were next. However, the summer O3 concentration was more than twice winter one. Winter/summer differences in PM10and PM2.5 particle concentrations were relatively not obvious, which indicates that responses of PM10 and PM2.5 particle concentrations to the difference of winter/summer heating period emission sources are far less distinctive than those of NOx, SO2, and CO. The correlation feature of winter/summer gaseous and particulate states depicts that both PM10 and PM2.5 particles were significantly correlated with NOx, and their correlations with NOx are more significant than those with other pollutants. Through PCA, it is found that there was a distinctive difference in the principal component combination structure of winter/summer PM10 and PM2.5 particles: SO2 and NOx dominated in the principal component of winter PM10 and PM2.5 particles; while CO and NOx played the major role in the principal component of summer PM10 and PM2.5 particles. For winter/summer PM10 and PM2.5 particles, there might exist the gaseous and particulate states correlation structures of different "combinations" of such dependent pollutant species. Research results also uncover that the interaction processes of gaseous and particulate states were also related with the vertical structure of UBL, that is to say, the low value layer of UBL O3 concentration was associated with the collocation of atmospheric vertical structures of the low level inversion,inverse humidity, and small wind, which depicts summer boundary layer atmospheric character, i.e.the compound impact of the dependent factor "combination" of wind, temperature, and humidity elements and their collocation structure on the variations of different gaseous pollutant concentrations. Such a depth structure of the extremely low value of O3 concentration in the UBL accords with its "inverse-phase" relation with other gaseous pollutant species. The PCA of meteorological factors associated with PM10 and PM2.5 concentrations also reveals the sensitivity of PM10 and PM2.5 concentration to the combinatory feature of local meteorological conditions.     

Heavy Air Pollution in Beijing and Possible Impact on Olympic Athletes

In 2001 the Olympic Games were awarded to the city of Beijing, China's second‐largest industrial center after Shanghai. Although the extreme air pollution in Greater Beijing has already been examined for some time in the scientific literature, it only gained public interest recently. The article summarizes the scientific facts.     

Reconnaissance environmental magnetic study of urban soils, dust and leaves from Bogotá, Colombia

Rock-magnetic investigations of environmental samples, such as soils, dust and leaves, can provide useful information on environmental stress. Aim of this paper is to report on the first magnetic survey carried out on environmental samples from Bogotá, Colombia, which is the fifth most populated city of Latin America. We studied three kinds of samples in order to evaluate their potential as pollution markers: soils, urban dust and leaves of the Sauco (Sambucus nigra) tree. Standard magnetic methods were used to analyze the three groups of samples, with special emphasis on leaves investigated here for the first time for environmental purposes. Samples were collected along two perpendicular transects in an area of the city presumably unpolluted, with two different systems of public transportation. Thermomagnetic curves obtained from soils and atmospheric dust show clearly defined ferrimagnetic phase (probably magnetite) as the main magnetic carrier. Curves of acquisition of isothermal remanent magnetization confirm the ferrimagnetic character of magnetic particles. Frequency-dependent magnetic susceptibility was found between 0 and 10%, suggesting less-important contribution of ultrafine super-paramagnetic magnetite. The apparent contradictory results between soils and the rest of samples may reflect different accumulation period for magnetic particles, being shorter for leaves and urban dust than for soils.     

Magnetic particles in atmospheric particulate matter collected at sites with different level of air pollution

Magnetic measurements of deposited atmospehric dust can serve as an additional parameter in assessing environmental pollution. This method is based on the assumption that atmospherically deposited particles contain significant portion of ferrimagnetic iron oxides of anthropogenic origin, which can be easily detected. Aim of this paper is to identify clearly magnetic fraction of daily samples of particulate matter less than 10 μm (PM10), routinely used for air quality assessment and monitoring. We used combination of thermomagnetic analyses and other physical and chemical methods, including scanning electron microscopy (SEM) and Mössbauer spectroscopy. Our results show that daily samples of PM10, collected at sites with different degree of atmospheric pollution, contain magnetite of spherical shape, which is presumably of industrial origin. Thus, magnetic methods can be applied directly to the same substances, which are used routinely in air quality assessment and monitoring.     

西安市道路灰尘磁学特征及其对环境的响应

西安市道路表面灰尘样品的环境磁学研究显示磁化率(χ)、非磁滞磁化率（χ_ARM）以及饱和等温剩磁（SIRM）均比较高,表明样品中磁性矿物含量较高.其中磁化率（χ）主要受人类活动强度影响,而非磁滞磁化率（χ_ARM）及饱和等温剩磁（SIRM）则由人为活动强度和磁性矿物种类共同决定.κ-T曲线以及等温剩磁（IRM）获得曲线显示样品中磁铁矿和磁赤铁矿等亚铁磁性矿物占主导,并可能含有少量的单质铁,其相对含量与人类活动种类有关：与单纯的交通排放及冶金活动相比,密集的人群流动可带来更多的单质铁矿物.磁畴图谱显示磁性矿物粒径变化不大,以准单畴及多畴颗粒等粗颗粒为主,明显大于成土作用形成的磁性颗粒.综合磁性矿物含量种类以及粒径可辨别污染及污染来源,提供污染监测的磁学手段,并初步进行污染来源划分.     

Vehicle-derived emissions and pollution on the road autovia 2 investigated by rock-magnetic parameters: A case study from Argentina

In this work, we carried out a preliminary study of traffic-derived pollutants from primary sources (vehicles), and on roads (paved area), road borders and surroundings areas. The study is focussed on the identification, distribution and concentration of pollutants and magnetic carriers. Magnetic parameters and their analyses suggest that the magnetic signal of vehicle-derived emissions is controlled by a magnetite-like phase. Magnetic grain size estimations reveal the presence of fine particles (0.1–5 μm) that can be inhaled and therefore are dangerous to human health. Magnetic susceptibility results (about 175 × 10⁻⁵ SI) show a higher magnetic concentration — magnetic enhancement — in the central area of the tollbooth line that is related to higher traffic. In addition, magnetic susceptibility was computed on several roadside soils along a length of 120 km and used to generate a 2-D contour map, which shows higher magnetic values (100–200 10⁻⁵ SI) near the edge of the road. The observed distribution of magnetic values indicates that magnetic particles emitted by vehicles are accumulated and mainly concentrated within a distance of several meters (1–2 m) from the edge of the road. In consequence, the magnetic susceptibility parameter seems to be a suitable indicator of traffic-related pollution. Non-magnetic studies show an enrichment of some trace elements, such as Ba, Cr, Cu, Zn and Pb, that are associated with traffic pollution. Furthermore, statistical correlations between the content of toxic trace metals and magnetic variables support the use of magnetic parameters as potential proxies for traffic-related pollution in this study area.     

Spatial structure and scale feature of the atmospheric pollution source impact of city agglomeration

The spatial structure and multi-scale feature of the atmospheric pollution influence domain of Beijing and its peripheral areas (a rapidly developed city agglomeration) is dissected and analyzed in this paper on the basis of the atmospheric pollution dynamic-chemical process observation data of the urban building ensemble boundary layer of the Beijing City Air Pollution Observation Experiment (BECAPEX) in winter (February) and summer (August) 2003, and relevant meteorological elements and satellite retrieval aerosol optical depth (AOD), etc. comprehensive data with the dynamic-statistical integrated analysis of "point-surface" spatial structure. Results show that there existed significant difference in the contribution of winter/summer different pollution emission sources to the component character of atmospheric pollution, and the principal component analysis (PCA) results of statistical model also indicate that SO2 and NOX dominated in the component structure of winter aerosol particle; instead, CO and NOX dominated in summer. Surface layer atmospheric dynamic and thermal structures and various pollutant species at the upper boundary of building ensembles at urban different observational sites of Beijing in winter and summer showed an "in-phase" variation and its spatial scale feature of "influence domain". The power spectrum analysis (PSA) shows that the period spectrum of winter/summer particle concentration accorded with those of atmospheric wind field: the longer period was dominative in winter, but the shorter period in summer, revealing the impact of the seasonal scale feature of winter/summer atmospheric general circulation on the period of atmospheric pollution variations. It is found that from analyzing urban area thermal heterogeneity that the multiscale effect of Beijing region urban heat island (UHI) was associated with the heterogeneous expansion of tall buildings area. In urban atmospheric dynamical and thermal characteristic spatial structures, the turbulent scale feature of the urban boundary layer (UBL) of architectural complexes had important impact on the multi-scale feature of urban atmospheric pollution. The comprehensive analyses of the variational analysis field of Moderate Resolution Imaging Spectroradiometer (MODIS) AOD-surface PM10 under the condition of clear sky and the correlation resultant wind vector field for pollution source-tracing suggest that the emission sources for winter Beijing atmospheric pollution aerosols particle might be remotely traced to the south peripheral greater-scale spatial range of Hebei, Shandong, Tianjin, etc., and the spatial distribution of the high value area of AOD was associated with that of the high value area of resident family number (heating surface source). The backward trajectory feature of winter/ summer air particles exhibits analogous multi-scale feature, and depicts the difference in the scale feature of the pollution sources spatial distribution in different seasons. The peripheral source trajectory paths of urban atmospheric pollution (UAP) mainly come from the fixed industrial surface source or heating surface source in the outskirt of Beijing, and the diffusion and transport distance of peripheral sources in winter is larger than one in summer. The above conclusions depict the multi-scale spatial influence domain and seasonal features caused by UAP source influence and atmospheric dynamical structure. The high value area of the winter Total Ozone Mapping Spectrometer (TOMS) AOD lay in the Beijing region and its south peripheral area, an S-N zonal pattern, which reflects the dynamical effect of peripheral topographic pattern on the diffusion of regional scale atmospheric pollution sources. Study suggests that the extent of winter atmospheric pollution within the "valley" megarelief in Beijing and periphery was close related with the pollution emission sources of the south peripheral area; and the significant "anti-phase" variation feature of winter AOD and sunshine duration in Beijing and its peripheral areas, and regional scale correlation of low cloud cover, fog days, and aerosols reflects the local climatic effect of aerosol influence in this region. Besides, analysis of the impacts of atmospheric dry/wet deposition distributions within a valley-scale on the regional water body of Miyun reservoir also reveals the possible influence of the multi-scale spatial structure of summer water, soil and atmospheric pollution sources on the water quality of Miyun reservoir.     

Mathematical Modeling of Diffusion and Transport of Pollutants in the Atmospheric Boundary Layer

— The process of dispersion of air pollutants, in a broad sense, can be considered as the net outcome of various mechanisms involved in the transport of air pollutants from the source to the receptor. The major mechanisms are: (1) advection of pollutants by mean air motion, (2) mixing of pollutants by atmospheric turbulence and (3) mass diffusion due to concentration gradients. In addition, the physical and chemical nature of the effluent, the location of the stack and the nature of the terrain downwind from the stack, effect the dispersion of the pollutants. Various physical and mathematical aspects related to the transport and diffusion of air pollutants in the atmospheric boundary layer are discussed here. Further, some aspects of dispersion in a weak wind stable boundary layer are described. Finally, the current issues in the modeling of weak wind boundary layer are illustrated.