The compositions, sources, and size distribution of the dust storm from China in spring of 2000 and its impact on the global environment

The average mass concentration of the aerosols in Beijing during the dust storm in the spring of 2000 was ~6000 mg·m^-3, ~30 times as high as that in the non-dust storm days. The enrichment factors of the pollution elements As, Sb and Se were higher than those in the non-dust storm days. This indicated that As, Sb and Se resulted from the pollution sources of those areas, through which the dust storm passed during their long-range transport, in addition to the local pollution sources in Beijing. The enrichment factors of the Pb, Zn, Cd and Cu were much less than those in the non-dust storm days, suggesting that the local pollution sources in Beijing area contributed to them mostly. The enrichment factors of elements Al, Fe, Sc, Mn, Na, Ni, Cr, V and Co were close to 1, showing that these elements originated from crust. The concentration of S in the dust storm was ~10 mg·m^-3, 4 times as high as that in non-dust storm. S in the aerosols resulted from the adsorption of gaseous SO₂ and the consequent transformation on it. The aerosols of the dust storm contained 16.1% and 76.9% of fine particles with the sizes less than 2.1 and 9.0 mm, respectively, while it had a large number of coarse particles. It was noted that a considerable portion of Fe(Ⅱ) was detected from the dust storm. Fe(Ⅱ) could easily dissolve in seawater to be nutrient for phytoplankton and would lead to the increase of the emission of dimethylsulfide (DMS) from the ocean. The feedbacks of Fe coupled with S in atmosphere might be the important mechanism that would affect the primary productivity in Pacific and/or the global climate change.     

北京大气污染区域分布及变化趋势研究

本文利用2000-2005年北京市8个国控点PM10、SO2、CO、NO2和NOX等污染物浓度数据,分析了北京各区域大气污染分布与季节变化特征,以及近几年大气污染变化趋势.方法以主成分分析为主,辅以时间序列分析.分析结果显示：北京大气污染存在明显的时空差异,第一、二主分量可以很好地表征城市大气污染属性,所有污染物对第一主分量贡献都为正值,能够清楚区分大气污染程度,以及城市与区域背景的异同,第二主分量可以区分城市污染的源排放特征.基于此标准,全市范围内大气污染划分为燃煤型、机动车排放型、过渡型以及环境背景等四种污染类型.     

Oxidative stress on plasmid DNA induced by inhalable particles in the urban atmosphere

Plasmid DNA assay is a newly-developed in vitro method to investigate bioreactivity of particles. In this paper, this method was used to study the bioreactivity of PM10 (particulate matter with aerodynamic diameter of less than 10 μm) and PM2.5 (particulate matter with aerodynamic diameter of less than 2.5 μm). Samples and dust storm particles were collected in 2001 in an urban area, a satellite city and a clean air area in Beijing. A big difference was found for oxidative DNA stress induced by different particulate matter (PM) samples, with the TM50 (particle mass causing 50% damage to DNA) values varying by a factor over 10. This was closely dependent on the sizes of particles as well as the variation in relative proportion of mineral matter. PM2.5 samples generally impose larger oxidative stress on plasmid DNA than PM10 samples. Airborne particles collected during dust storm episodes, usually with a higher proportion of mineral matter, have a much lower oxidative capacity than those collected during non-dust storm episodes. PM samples and their water-soluble fractions usually have similar bioreactivities, demonstrating that oxidative capacity of Beijing airborne particles is mainly sourced from their water-soluble fractions.     

Inorganic chemical composition and source signature of PM2.5 in Beijing during ACE-Asia period

Aerosol samples for PM2.5 were collected in Beijing for 38 consecutive days from March to April 2001 using an IMPROVE Sampler. Concentrations of 20 elements in PM2.5 were determined using a PIXE method. Results show that the average mineral dust concentration of PM2.5 was 14.6 Ilg/m3 during the observation period. On the sand-dust event days of March 21 and April 10, dust PM2.5 mass concentrations were 62.4 and 54.1 μg/m^3, respectively.These demonstrate that fine particle pollution by dust event in Beijing was very severe. The enrichment factors of S and Cu reached minimums on the dusty days and were high on the non-dusty days. It is considered that enrichment factors of elements in PM2.5, which are associated with human activities, can probably provide an effective method to distinguish local sources from external sources of dust. Factor analysis on the chemical composition in PM2.5 shows that sources of crustal matters, anthropogenic emission, and oil combustion contributed to PM2.5 levels in air in the springtime of 2001 in Beijing.     

Coupling and feedback between iron and sulphur in air-sea exchange

Iron in surface seawater has been demonstrated to be the limiting nutrient factor for primary productivity in certain oceanic regions where other major nutrients are abundant[1—5]. The available Fe to the phytoplankton in seawater is related to the uptake of carbon dioxide through the ocean and, in turn, to the global greenhouse effect[6—11]. Recent reports showed that the available Fe in the seawater is closely correlative to nitrogen fixation in the ocean[12—17]. Understanding which Fe s…     

石家庄市大气颗粒污染物主要成分及其来源分析

总悬浮颗粒物(TSP)是对环境与人体健康造成危害的主要物质。因此,本文对石家庄市大气悬浮颗粒物的时空分布和组成进行分析,探究了导致石家庄市产生雾霾的物质及其来源。结果表明:(1)研究区PM_(10)和PM_(2.5)平均浓度差异性较小,且高于《环境空气质量标准》(GB3095-2012)中所规定的年平均二级浓度限值;(2)西南高教的PM_(10)浓度相对较小;(3)石家庄市冬季TSP、PM_(10)和降尘的浓度均高于夏季;(4)TSP和PM_(10)二者所含重金属种类和含量高低顺序基本一致,由高到低依次为Ca、Al、Fe、Zn、Pb、Cu、Ni、Cr、Cd;(5)冬季(雾霾期)与夏季(非雾霾期)污染物主要化学组分基本一致,但冬季各元素含量明显高于夏季。     

Territorial Features of Atmospheric Environment in Beijing and Impact of Dust-storm

1Introduction　TheenvironmentproblemsontheEarthcanbeclassifiedasthreekinds ,whicharecalledasthelocalenvironment,terri torialenvironmentandglobalenvironmentproblems ,respec tively .Nowthekindsofanthropogenicactivityhaveledtotheseriousterritorialenvironmentproblemsallovertheworld .Recently ,theterritorialenvironmentproblemsinChinahavebeengraduallyrecognized .　Nowalthoughtheseparateseriouspollutionshavebeende creasedbyremovingandcontrollingthestrongpollutionsources ,theterritorialpollutionprobl…     

兰州皋兰山顶春季大气气溶胶的监测与分析

对兰州皋兰山顶春季大气气溶胶连续采样，得到了大气背景、浮尘、扬沙、沙尘暴等不同天气条件下的气溶胶质量浓度．通过沙尘天气的过程分析，得到不同沙尘天气条件下，TSP浓度的时间变化规律．与兰州大学小二楼顶的监测数据进行比较分析，可以看出兰州市的污染状况和TSP的时空分布．通过各类沙尘天气不同粒径气溶胶粒子的浓度分析，发现气溶胶粒子粒径的分布规律和气溶胶来源不同．     

北京市夏季大气气溶胶 PM2.5和 PM10成分特征?

对北京市城区2012年夏季大气对气溶胶进行每日PM2.5和PM10石英膜采样,得到了可溶性离子质量浓度和16种元素的质量浓度,并结合气象观测值进行了分析.结果显示,采样期间,PM2.5质量浓度为9.58~210.42μg·m-3,平均值102.81μg·m-3;PM10质量浓度为33.75~288.33μg·m-3,平均值159.66μg·m-3.PM2.5和PM10质量浓度都与采样点能见度、风速呈负相关,与相对湿度呈正相关.质子荧光分析(PIXE)结果显示,S、K、Ca和Fe在PIXE可分析元素中含量较高,在PM2.5和PM10都占89%.且元素Ca、Ti、Sc、Cr、Fe主要存在于粗粒子(PM2.5~10)中,而元素S、Cu、Zn、As、Br、Pb主要存在于细粒子(PM2.5)中.富集因子分析表明,元素K、Ca、Ti、V、Mn、Ni主要为地壳来源,元素S、Cl、Cu、Zn、As、Br、Pb主要来自于人为源.SO2-4、NO-3、NH+43种可溶性离子总质量浓度占PM2.5浓度的43.5%,占PM10浓度的25.4%.     

Speciation of the elements and compositions on the surfaces of dust storm particles： The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The major species of iron on the surface were oxides, sulfate, silicate,FeOOH and minor part sorbed on SiO2/Al2O3. Sulfate is the dominant species of sulfur on the surface. SiO2 and Al2O3 are the main components of Si and Al on the surface respectively.One of the most important findings was that the Fe(Ⅱ) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 20, 2002, while Fe2(SO4)3,one of the Fe(Ⅲ) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe enriched on the surface of aerosol particles. Fe(Ⅱ) accounted for 1.3%-5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to support the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.     

沙尘天气过境前后北京大气污染物质量浓度的变化

影响北京的沙尘天气可分为沙尘暴、浮尘和扬沙3种类型。沙尘暴和浮尘天气发生前后的污染物类型和质量浓度ρ有明显的差异，属2类不同性质的污染。在沙尘天气发生之前，大气中SO2，NO2等气态污染物的ρ往往较高，在大气逆温的情况下污染尤其严重，并且与颗粒物的ρ相关性较好；随着沙尘天气的爆发，颗粒物的ρ骤然增加，但伴随沙尘天气出现的大风使SO2，NO2等污染物的ρ显著下降，大气污染转变为由降尘过程造成的相对单一的颗粒物污染，属典型的沙尘污染。     

基于单颗粒质谱技术的石家庄市2016年秋季空气重污染成因分析

利用单颗粒气溶胶质谱仪并综合地面空气污染监测数据、常规气象观测数据、卫星遥感火点监测资料和气流后向轨迹,分析了2016年石家庄市秋季出现的两次空气重污染过程的演变特征及主要影响因素。结果表明：机动车尾气和地面扬尘是PM_2.5的重要来源。高低空稳定的天气形势配置是两次重污染过程形成的直接原因。在这些天气形势下,湿度高、风速小、气压低、逆温层厚、混合层高度低是造成两次重污染过程的重要原因。同时东南和西南方向周边污染物的输送对重污染天气的形成发展也有一定的贡献。     

MSA in Beijing aerosol

Methane sulphonate (MSA) and sulfate (SO4^2-),the main oxidation products of dirnethyl sulfide (DMS), arethe target of atmospheric chemistry study, as sulfate aerosolwould have important impact on the global climate change. It is widely believed that DMS is rnainly emitted from phyto-plankton production in marine boundary layer (MBL), andMSA is usually used as the tracer of non-sea-salt sulfate (nss-SO4^2-) in marine and coastal areas/MSA/SO4^2- = 1/18) Manyobservations of MSA were in marine and coastal aerosols. Toour surprise, MSA was frequently (＞60%) deteeted in BeijingTSP. PM10, and PM2.5 aerosols, even in the samples collectedduring the dust storm period. The concentrations of MSAwere higher than those measured in marine aerosols. Factoranalysis, correlation analysis and meteorology analysis indi-cated that there was no obvious marine influence on Beljiagaerosols. DMS from terrestrial emissions and dimethyl sulphoxide (DMSO) from industrial wastes could be the twopossible precursors of MSA. Warm and low-pressure airmasses and long time radiation were beneficial to the forma-tion of MSA. Anthropogenlc pollution from regional andlocal sources might be the dominant contributor to MSA inBeijing aerosol. This was the first report of MSA in aerosolscollected in an inland site in China. This new finding wouldlead to the further study on the balance af sulfur in inlandcities and its global bingcoehemical cycle.     

某铀尾矿库区夏季大气颗粒物污染特征研究

采集了某铀尾矿库区夏季大气颗粒物（TSP、PM2.5）,检测分析了颗粒物质量浓度及铀、重金属（Pb、Cd、Cu）含量,结果表明：TSP的质量浓度为53.9μg/m3,PM2.5的质量浓度为28.0μg/m3,TSP与PM2.5的质量浓度的相关系数R=0.832 2;TSP中铀的含量为0.078μg/m3,PM2.5中铀的含量为0.025 6μg/m3;TSP中Pb、Cd、Cu的含量分别为0.111 2μg/m3、0.014 9μg/m3、0.179 7μg/m3,PM2.5中Pb、Cd、Cu的含量分别为0.063 9μg/m3、0.007 4μg/m3、0.038 1μg/m3;TSP中重金属含量由高到低的顺序是Cu＞Pb＞Cd,PM2.5中重金属含量由高到低的顺序是Pb＞Cu＞Cd。     

系统聚类方法对大气污染地区的划分

当前国内经济快速发展的同时带来了环境质量下降等问题,地区间发展落脚点不同,受到的大气污染程度不同。从主要的大气污染监控物PM2.5、PM10、一氧化碳、二氧化碳、臭氧和二氧化硫6个方面构建大气污染地区分类的聚类评价指标体系,建立地区分类的聚类分析模型。并以北京、上海、海口、西安、佛山、酒泉、拉萨和重庆8个城市为例,应用评价指标的数据进行聚类分析,根据聚类结果提出具有针对性的环境保护建议.     

Size distribution and element composition of dust aerosol in Chinese Otindag Sandland

Dust aerosol is one important component of atmos-pheric aerosols, and plays important roles in the Earth’s climate system and the biogeochemical cycle. Large amounts of dust aerosols produced from windblown soils and deserts are emitted annually into the atmosphere and transported over long distance to downwind land and ocean areas[1]. The deserts and desertification soils in northern China are important sources of East Asia dust aerosols. It is estimated that 800 Mt of dust aerosols emit-t…     

环境空气质量标准修订后城市空气质量变化趋势及污染特征分析 ——以济南市为例

2012年环境空气质量标准修订后,大气污染物监测指标与频次发生变化,在一定程度上影响了城市空气质量评价及污染特征判定。为进一步促进城市空气质量改善,为地方环境管理与决策提供科学支撑,通过运用统计分析、趋势检验及相关分析等方法研究了济南市执行新环境空气质量标准后,各时段城市空气质量及6项污染物浓度变化趋势,在此基础上识别了空气污染特征。结果表明：自2013年起,PM10、PM2.5浓度不断下降,SO2、CO持续达标,近3年间全市无污染天数占50%左右;从季节变化来看,冬季大气污染最为严重,夏秋两季空气环境质量较好;PM10、PM2.5与NO2长期处于超标水平,O3污染愈加严重。可见济南市环境空气质量虽日趋改善,但以PM10、PM2.5和O3污染为代表的复合型大气污染特征已经形成。     

某企业周边环境降尘中的重金属含量及生态风险分析

目的 研究宝鸡市某企业周边环境降尘中的重金属元素污染状况及生态风险分析,为环境保护管理部门正确决策提供科学依据.方法 在某企业周边布设6个降尘点位进行采样,用原子吸收法测定采样中的Pb,Zn,Cu,Cd,Cr,Ni和Fe七种金属元素含量,再采用富集因子法对金属元素的来源进行分析,并采用潜在生态风险指数法对周边环境进行生态风险评价.结果 某企业周边环境降尘中7种重金属分析结果表明,Cd和Pb超标最为严重,其均值分别是陕西省土壤相应元素背景值的661倍和196倍多;其次是Zn和Cu分别是陕西省土壤相应元素背景值的76倍和7倍多.富集因子计算结果表明,该企业周边环境6个点位的降尘中的重金属元素均已极强富集,该区域环境已受严重污染.潜在生态风险指数法评价结果表明,该企业周边环境降尘中重金属已经达到严重污染水平,周边环境存在严重潜在生态危害.结论 某企业周边环境降尘中重金属已经达到严重污染水平,该周边环境存在严重潜在生态危害.     

西安冬季高层公寓室内外颗粒物浓度水平与变化

 以西安市冬季某研究生高层公寓为监测对象, 通过1 min 时间间隔同步监测, 研究了不同楼层室内外空气中颗粒物PM1、PM_2.5、PM₁₀以及总悬浮颗粒物TSP 的质量浓度、分布状况与变化特征。结果表明, 西安市冬季高层公寓存在严重的颗粒物污染, 室内粗颗粒物PM₁₀质量浓度为(65.5±20.0)~(142.0±16.9)μg/m³, 略低于室内空气质量标准, 但室内细颗粒物PM_2.5及超细颗粒物PM1分别为(52.2±14.3)~(111.5±12.2)μg/m³和(50.6±13.9)~(108.7±11.9)μg/m³, 其中PM_2.5质量浓度占总悬浮颗粒物TSP 的50%以上;室外以粗颗粒物PM₁₀为主, 楼层高度与颗粒物质量浓度之间无显著关联。     

衡阳市区空气颗粒物的污染特征研究

2014年4~5月在衡阳市区四个典型的城市功能区设置采样点,共采集了47个大气样品,对空气颗粒物（ TSP、PM2.5）的污染状况进行调查,分析其中的重金属（ Pb、Cd、Cu、As、Hg）含量及其形态分布.结果表明,大部分采样点PM2.5浓度超过国家环境空气质量标准（ GB3095—2012）中的二级浓度限值,部分地段TSP浓度超标;空气颗粒物中重金属元素质量含量大小的顺序为：Pb＞Cu＞As＞Cd＞Hg,这些重金属元素更容易富集在细颗粒物PM2.5上;形态分析表明,As、Hg主要以残渣态存在, Pb、Cd、Cu则以可交换态和残渣态存在较多.