Atmospheric pollution assessment near potential source of natural aerosols in the South Gobi Desert region,China

ABSTRACT

Rapid economic growth, a high degree of urbanization and the proximity of a large number of desert and semidesert landscapes can have a significant impact on the atmosphere of adjacent territories, leading to high levels of atmospheric pollution. Therefore, identifying possible sources of atmospheric pollution is one of the main tasks. In this study, we carried out an analysis of spatial and temporal characteristics of five main atmospheric pollutants (PM_2.5, PM₁₀, SO₂, NO₂, and CO) near potential source of natural aerosols, affecting seven cities (Wuhai, Alashan, Wuzhong, Zhongwei, Wuwei, Jinchang, Zhangye), located in immediate proximity to the South Gobi deserts. The results, obtained for the period from 1 January 2016 to 31 December 2018, demonstrate total concentrations of PM_2.5 and PM₁₀ are 38.2 ± 19.5 and 101 ± 80.7 μg/m³ exceeding the same established by the Chinese National Ambient Air Quality Standard (CNAAQS), being 35 and 70 μg/m³, respectively. Based on the data from Moderate Resolution Imaging Spectroradiometer (MODIS) for the whole period, Clean Сontinental (71.49%) and Mixed (22.29%) types of aerosols prevail in the region. In the spring and winter seasons maximum concentrations of pollutants and high values of Aerosol Optical Depth (AOD) in the region atmosphere are observed. PM_2.5 and PM₁₀ ratio shows the presence of coarse aerosols in the total content with value 0.43. The highest concentrations of pollutants were in the period of dust storms activity, when PM_2.5 and PM₁₀ content exceeded 200 and 1000 µg/m³, and AOD value exceeded 1. UV Aerosol Index (UVAI), Aerosol Absorbing Optical Depth (AAOD), and Single Scattering Albedo (SSA), obtained from Ozone Monitoring Instrument (OMI), demonstrate the high content of dust aerosols in the period of sandstorms. Analysis of backward trajectories shows that dust air masses moved from North to Northwest China, affecting large deserts such as Taklamakan, Gurbantunggut, Badain Jaran, Tengger, and Ulan Buh deserts.     

具有尘带的椭圆星系的红外辐射特性

IRAS在12,25,60和100μm的巡天,给我们提供了研究各类星系红外辐射特性的可能。为了研究具有尘带的E和SO星系的红外辐射特性,我们利用了E.Sadler给出的完备的E和SO星系表。在该星系表中共列出248个夭体,其中38个被证记为IRAS点源,且又有确切的60和100μm的流量值。在这38个天体中有6个被列在K.Ebneter和B.Balik最新发表的具有全带的椭圆星系表中。我们以这6个星系作为具有尘带的E和SO星系的样本,其它32个没有尘带的E和SO星系即作为对照样本。为了讨论具有尘带的椭圆星系的红外辐射特性,我们利用非参数Mann-Whitney检验,对这两个样本的LIR和FIR/FB的分布作了讨论,结果是在对于置信度α=0.05的水平上,我们不能拒绝另一假设:这两个样本的LIR和FIR/FB的分布是相同的。对于同时具有25,60和100μm确切流量的E和SO星系我们讨论了它们的双色图,结果发现,不具尘带的E和SO星系都处于Rowan-Robinson.et al所指出的正常星系区,而一些具有尘和带的ESO星系,则远离这一区域,它们是LINER和SEYFERT星系。     

Oxygen isotope compositions of quartz grains (4–16 μm) from Chinese eolian deposits and their implications for provenance

Oxygen isotope compositions were measured in quartz grains extracted from a 7.0 Ma red clay-loess sequence at Lingtai and six late Pleistocene loess sediments (Malan loess). Results show that the changes in oxygen isotope compositions of Malan loess are basically controlled by the geochemical characteristics of the source materials, while the effect of weathering process after dust deposition could be minor. The oxygen isotope distribution of quartz grains from red clay at Lingtai is similar to that of the overlying loess-paleosol sequence, thus indicating that the red clay at Lingtai has the same eolian origin as the loess-paleosol deposits. Furthermore, the oscillations of the isotope compositions in 4–16 μm-sized quartz grains may reflect the changes, to some extent, of the climatic systems of the source region.     

纤粒矿物粉尘体外细胞毒性研究

采用体外细胞培养技术,观察兔肺泡巨噬细胞死亡率,用丙二醛（ＭＤＡ）的含量变化、乳酸脱氢酶（ＬＤＨ）及超氧化物歧化酶（ＳＯＤ）的活性变化来评价来自１２个矿６床的６种矿物的１２种结晶习性的矿物粉尘的细胞毒性,探讨其使巨噬细胞受损的机制。结果显示：沸石、硅灰石无细胞毒性,而其他的纤维状及片粒状矿物粉尘则表现出不同程度的细胞毒性,说明矿物粉尘的细胞毒性与矿物粉尘的形态有一定关系,但主要由矿物粉尘的特性所决     

成都市近地表大气尘的矿物学特征及其环境指示意义

通过对成都市近地表大气尘X射线衍射、电镜扫描分析等研究显示:其主要由石英、长石、伊利石、绿泥石、方解石、石膏等矿物组成;就其形状看有致密的不规则粒状、片状单矿物、不规则粒状聚合体、浑圆形球状飘珠、聚合体放大观察可见片状的粘土矿物和细小的粒状单矿物,偶见藻类;矿物形貌特征及矿物组成空间分布特征的研究显示:球形状飘珠及伊利石、绿泥石、石膏的空间分布特征与工业布局和表层土壤的pH值密切相关,成都市近地表大气尘主要为地表扬尘和工业烟尘的混合物;与土壤的矿物组成比较可见,近地表大气尘重金属污染除土壤贡献外,还有其他污染贡献;石膏在本次研究中平均含量高达8.2%,推测可能成为成都市往年燃煤量大而无明显酸雨现象的原因之一。     

GIS辅助的吴淞工业区铺设道路扬尘估算

本文以上海市的吴淞工业区为研究对象,借鉴美国EPA提出的AP-42方法,利用动力学粒径谱仪的粒径分析结果对公式系数进行修正,在GIS手段的辅助下对吴淞工业区铺设道路不同粒径的扬尘量进行估算,最终由V isualBasic语言和MapObjects2.0组件建立的铺设道路扬尘管理信息系统表明GIS的使用有利于加强扬尘污染的研究和控制。     

Mass Concentration and Mineralogical Characteristics of Aerosol Particles Collected at Dunhuang During ACE-Asia

Measurements were performed in spring 2001 and 2002 to determine the characteristics of soil dust in the Chinese desert region of Dunhuang, one of the ground sites of the Asia-Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The mean mass concentrations of total suspended particle matter during the spring of 2001 and 2002 were 317 μg m?3 and 307 μg m?3, respectively. Eleven dust storm events were observed with a mean aerosol concentration of 1095 μg m?3, while the non-dusty days with calm or weak wind speed had a background aerosol loading of 196 μgm?3 on average in the springtime. The main minerals detected in the aerosol samples by X-ray diffraction were illite, kaolinite, chlorite, quartz, feldspar, calcite and dolomite. Gypsum, halite and amphibole were also detected in a few samples. The mineralogical data also show that Asian dust is characterized by a kaolinite to chlorite (K/C) ratio lower than 1 whereas Saharan dust exhibits a K/C ratio larger than 2. Air mass back-trajectory analysis show that three families of pathways are associated with the aerosol particle transport to Dunhuang, but these have similar K/C ratios, which further demonstrates that the mineralogical characteristics of Asian dust are different from African dust.     

土壤、大气尘中晶体的组成及其物源指示意义——以长沙、株洲和湘潭地区为例

基于长沙、株洲和湘潭地区大气尘(可吸入颗粒和近地表积尘)和表层土壤的X-射线衍射(XRD)分析数据,采用微量相鉴定方法获得的结果显示,大气尘和表层土壤中包含石英、石膏、方解石、白云石、硫酸镉等自然矿物及SiS_2、NiTi、Cd_3As_2、FeOCl等非自然源晶体。比较了长沙、株洲、湘潭地区大气尘与表层土壤的晶体组成,分析了大气尘矿物及非自然源晶体的空间分布,探讨了其环境指示意义。     

Variations in dust event frequency over the past century reflected by ice-core and lacustrine records in north China

In this paper, we analyzed the variations of dust proxies in the Dunde, Malan and Chongce ice cores from the northern Tibetan Plateau and the Hongjiannao lacustrine sediment core from north Shaanxi Province, and found that they all showed a general decrease trend over the past century. Owing to the fact that all these ice cores and lacustrine core were retrieved from the margins and/or the leeward sides of the major areas of dust events in north China, their records could suggest that the dust event frequency in north China declined over the study period. This decrease trend might be attributed to increasing precipitation and weakening westerly. However, human activities have made the areal extent of desertification expand acceleratingly in north China. This status could make it possible that dust events would occur on a large spatial scale under the future climate change, which would be a big environmental issue we shall face.