北京市大气颗粒物中Cd的地球化学分布特征及其生态风险评估

采集北京市11个区县内的大气颗粒物样品,分析了TSP、PM10、PM2-5的含量分布特征,重金属元素Cd在大气颗粒物中的地球化学分布特征及其生态风险,结果表明：北京市3种粒径的大气颗粒物中PM2-5的超标幅度最大,并且PM10中载带的重金属大部分都集中在PM2-5中。除密云、通州地区外,Cd元素在不同粒级大气颗粒物中浓度的高低表现为 TSP＞PM10＞PM2-5;不同功能区相比,公园中大气颗粒物中Cd元素浓度明显高于农田区和教育区,因此公园的环境质量问题应该引起相关部门的关注。研究区内不同粒径大气颗粒物中Cd元素的非致癌风险较小,但与其他地区相比,海淀区的非致癌风险较高,大气颗粒物超标幅度最大,因此应该重视海淀区的环境健康问题。     

北京市冬季、春季PM_(10)和PM_(2.5)中元素地球化学特征

使用TH1500C智能中流量(80~120 L/min)大气采样器采集了北京市区5个功能区和郊区的大气颗粒物(TSP/PM_(10)/PM_(2.5))样品,利用电感耦合等离子体质谱仪和原子荧光谱仪分析测试了大气颗粒物中Al,Fe,Mn,As,Hg,Cd,和Cr等21种元素,并通过计算元素的富集因子探讨了大气颗粒物中元素的来源。结果表明,冬季大气颗粒物PM10中Cd,Cr,As,Hg的浓度比春季的分别增幅233%,306%,298%和141%;在PM2.5中的增幅分别为442%,309%,310%和256%。Cd,Cr,As,Hg和Se等元素均表现出在PM_(2.5)中富集的趋势,并且其在冬季的浓度明显高于春季。认为冬季燃煤取暖对大气颗粒物中的污染元素贡献较大,主要贡献元素为Cd,As和Hg。     

银川市城郊PM2.5质量浓度日变化规律与组成特性分析

可吸入大气颗粒物是空气中的一种主要的污染物,虽然它在大气中含量很少,但对环境和人体的危害都很大。其中大气颗粒物PM2.5(空气动力学粒径Da≤2.5μm的大气颗粒物)与人体健康状     

贵阳城区大气污染物的时空变化和复合污染特征

选取贵阳市10个空气质量监测站发布的PM2.5、PM10、SO2、NO2、CO和O3实时浓度数据，通过时间序列分析法和插值法研究贵阳市大气污染物的时空变化和复合污染特征。结果表明:（1）贵阳市2014-2018年主要污染物PM2.5和PM10的年平均浓度逐渐下降，光化学污染物O3年平均浓度有所增加，空气质量逐渐转好，环境治理取得明显效果；（2）2018-2019自然年PM2.5、PM10、NO2和O3在春季污染最严重，SO2和CO在冬季污染最严重，反映出污染源、阶段性燃料燃烧和二次离子生成等因素对不同污染物的影响不同；（3）PM2.5和PM10日变化特征为“午峰晚峰”型，峰值发生的时间因季节而异，主要由不同季节人类作息的起止时间不同所致，O3日变化为单峰型，夜间O3浓度较低，从早晨8:00点开始随着太阳辐射的增大和温度的升高，在15:00-16:00点左右达到峰值；（4）PM2.5的空间分布呈现出部分郊区和工业区较高，市中心居民区较低的特征，指示城市建设向郊区推进。O3浓度呈现出市区低、郊区高的空间分布特征，反映郊区植被覆盖好，释放的天然源VOCs促进了O3生成；（5）主要污染物O3与颗粒物PM2.5和PM10在春季造成的复合污染最为严重，在夏季O3与PM10造成一定程度的复合污染，在秋冬季O3浓度最低，O3与颗粒物不产生复合污染；一天之内同一时刻O3与颗粒物不会产生叠加从而造成复合污染。      

黑龙江省松嫩平原南部大气颗粒物地球化学特征及来源解析

研究采集了黑龙江松嫩平原南部28个夏季大气颗粒物样品,分析了不同粒径(TSP、PM10、PM2-5)样品中常量和微量元素含量,对元素浓度含量特征、元素间相关性和空间分布特征进行了分析,并使用富集系数法和因子分析法进行元素来源解析。研究表明：在PM10-100中富集的元素多在地壳中含量很高,重金属元素在PM2-5中高度富集,不同粒径大气颗粒物中各元素质量浓度整体水平为：大庆>绥化>哈尔滨>齐齐哈尔。富集因子分析表明：Fe、K、Ti、Mn、Co的富集因子小于1或非常接近1,Ca、Mg、Ni、Cr的富集因子大于1但仍小于10,Na、Zn、Cu、Cd、Pb、Se的富集因子大于10,表现出较为明显的人为来源特征。参照颗粒物不同源主要标识元素,对各元素进行主因子分析结果表明：松嫩平原南部大气可吸入颗粒物的主要来源是土壤扬尘,此外还有燃煤、垃圾焚烧、汽车尾气、碱尘大气传输、燃油和工业来源。     

北京市大气颗粒物中全氟烷基化合物的粒径分布特征

人为排放的持久性有机污染物倾向于在细级大气颗粒物中富集,但目前国内外关于大气颗粒物中全氟烷基化合物(PFASs)粒径分布在不同国家地区有显著差异,而在我国北京地区PFASs在不同粒径大气颗粒物中的富集能力尚不清楚。本文采用五级大流量主动分级采样器采集了北京市大气颗粒物样品,利用超声萃取结合高效液相色谱-电喷雾负电离源串联质谱测定PFASs含量,探讨了该地区大气颗粒物中PFASs的浓度水平和粒径分布特征,以及大气颗粒物浓度变化对PFASs浓度变化的影响。结果表明:研究区∑PFASs范围为10. 1～62. 9 pg/m3,76. 4%～83. 8%的PFASs集中分布在PM2. 5颗粒物中,其中含量较高的PFOA、PFNA和PFDA在0. 25μm细颗粒物中占比最高,分别为26. 3%～43. 7%、30. 3%～68. 6%和30. 6%～49. 7%; PFOS在0. 25μm细颗粒物中没有检出,主要分布在1～2. 5μm和0. 25～1μm颗粒物中。此外,研究发现北京市霾天大气颗粒物中∑PFASs为晴天的3. 5倍,且不同粒径大气颗粒物浓度变化对PFASs各化合物表现出不同的富集能力,其中PFOA、PFOS、PFNA和PFDA等中链PFASs更易富集。     

太原市大气颗粒物中有机物浓度的分布特征

首次研究了太原市大气颗粒物中的有机物分布特征。收集了太原市不同功能区冬夏两季的大气颗粒样品,经抽提分离取得饱和烃、芳香烃、非烃、沥青质4组馏分。分析结果表明:(1)大气颗粒中有机物浓度在取暖期高于非取暖期;(2)各功能区的有机污染程度不同,太钢工业区>长风剧场商业居民混合区>一电厂化工区、太行文化区。(3)各馏分浓度中沥青质含量普遍高,饱和烃含量最低,非烃、芳香烃馏分居中,且相对较低。(4)太原市整体污染主要为煤的燃烧和工业生产、尾气排放。     

兰州市取暖期可吸入颗粒物中单颗粒矿物组成特征

为研究兰州市2005年冬季大气可吸入颗粒物(PM10)中单颗粒的矿物组成,用能谱扫描电镜识别和统计了兰州市区(东方红广场)和郊区(榆中县)两个采样点的单矿物颗粒。结果在市区样品中识别出方解石、伊/蒙混层、石英、斜长石、伊利石、石膏、绿泥石、高岭石、浊沸石和钾长石等21种矿物,前7种占统计总量的75%以上;郊区样品中识别出20种矿物,以方解石、石英、伊利石、绿泥石、斜长石和伊/蒙混层为主(占70%以上),与市区相比缺少钾石膏、金红石和水铝酸钙而增加了硫酸镁和磷灰石。总体来看,大气PM10中的矿物颗粒可分为粘土类、长石类、碳酸盐类、硫酸盐类、氧化物类和其他六类,以粘土类和碳酸盐类矿物为主(约占60%);冬季市区颗粒物表面的“硫化”现象较郊区严重;这些矿物颗粒主要来自地表土,人为排放和大气中二次化学反应生成的矿物的贡献较小。     

北京西北城区一次重污染过程中PM10的氧化损伤能力研究

为评估大气重污染期间北京市可吸入颗粒物(PM_(10))的毒性,采集2016年3月份一次大气重污染过程中北京市大气PM_(10)样品,应用质粒DNA损伤评价法来研究其氧化损伤能力。结果表明,雾霾期间PM_(10)对DNA的损伤率高于雾霾逐渐消退时期,远高于雾霾前期清洁天,颗粒物对DNA损伤率随剂量的增加而增加。雾霾前后PM_(10)水溶样品的平均TD_(20)值表现为雾霾前清洁天(788.01μg/mL)雾霾消退后期(470.40μg/mL)雾霾期间(55.78μg/mL),说明氧化能力雾霾期间雾霾消退后期雾霾前清洁天。另外通过雾霾前后数据对比得到,暴露毒性指数TI大小顺序为雾霾期间(13 245.06)雾霾消退后期(1 658.87)雾霾前清洁天(254.08),说明雾霾期间PM_(10)对人体危害更大。     

辽宁省典型地区大气颗粒物重金属元素分布特征及对土地质量影响研究

大气颗粒物是大气质量评价中的一个通用的重要指标,近年来,对于大气颗粒物污染这一热点问题开展了大量的研究。文中选取辽宁省沈阳市、锦州市和葫芦岛市等典型地区研究大气颗粒物(TSP、PM10、PM2.5)中Cd等重金属元素的分布特征。结果表明,辽宁省大气可吸入颗粒物中Pb和Zn的含量最高,其次是Cu、Mn、As、Cr、Cd。燃煤、燃油和工业污染源等方面可能是造成这些元素含量较高的主要原因。此外,文中还对大气颗粒物对土地质量的影响研究进行一些有益尝试。研究表明,大气颗粒物中重金属元素含量对土地质量的影响是显而易见的。政府管理部门应该重视对大气颗粒物中重金属元素含量的监控,努力减少其对土地质量的影响。     

兰州市大气飘尘中有机物浓度的变化及其分布特征

本文收集了兰州市区和郊区在取暖期和非取暖期的大气飘尘样品和汽车尾气及烟尘样品。对这些样品中有机物总量以及备馏分，即:饱和烃、芳香烃、非烃和沥青质进行了定量分析，结果表明:（１）大气飘尘中有机物浓度在取暖期高于非取暖期，且市区高于郊区；（２）通过对烟尘和汽车尾气样品中有机物各馏分浓度与兰州市区大气飘尘的样品各馏分浓度的比较，其结果是西团区受工业污染较为严重，盘旋路受汽车尾气的污染较为严重，铁路局受烟尘的污染较为严重；（３）兰州市整体污染主要受到燃煤、汽车排放的尾气和工业生产等污染，但具体某一季节或某一区域，这三者之间污染程度有一定的差异。     

Elements’ Geochemical Characteristics of PM10 and PM2.5 in Beijing During Winter and Spring

From 2012 to 2013, heavy haze frequently hit Beijing in spring and winter. The fine atmospheric particulates can be inhaled by people, and remain in the respiratory tract and lung for quite a long time. The heavy metal elements in the particles are harmful, and even carcinogenic to human bodies. Therefore, it is necessary to master the geochemical characteristics and the temporal and spatial distribution of the heavy metal elements in atmospheric particles. The atmospheric particulates (TSP/PM₁₀/PM_2.5) were collected by using TH1500C intelligent medium volume (80~120 L/min) air samplers in the five functional areas and suburbs of Beijing, respectively in January 2013 (heating period) and April 2013 (non-heating period). The five functional areas were: building materials factory area, residential area, education area, business area and recreation area, each functional area having three sampling sites, and five in suburbs. The sampling height was 1.5 m above the ground and the distance of the sampling sites to roads exceeded 50 m so as to avoid excessive impact of vehicle exhaust emissions. These samples were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Optical Emission Spectrometer(ICP-OES)and Atomic Fluorescence Spectrometer (AFS), by which 21 elements including Al, Fe, Mn, As, Hg, Cd, Cr were tested. Based on the comparisons of the concentration and element content variation of atmospheric particulates of these functional areas in and after the heating period, the spatial distribution of atmospheric particulates and the influence of coal combustion on the concentration and composition of atmospheric particulates were revealed. The elements sources of atmospheric particulates were also discussed by computing the enrichment factor of the elements, providing a scientific basis for the air contaminant treatment in Beijing. The results showed that the total concentration of the 21 elements of PM₁₀ and PM_2.5 in the functional areas of Beijing in winter was higher than that in spring, the most marked among them being the business area. In winter, the concentration of pollution elements in the building materials factory area and the business area in Beijing was extremely high, and the residential area, education area, recreation area and suburbs where people live were much better, among which the education area was the best. The concentration change of particulates in suburbs was quite smaller in winter and spring than that of the urban area. It also showed that the concentrations of Cd, Cr, As and Hg in PM₁₀ increased by 233%,306%,298%,141%,respectively and the increase in PM_2.5 was 442%、309%、310%、256%, respectively. These abovementioned elements show a tendency to accumulate mainly in PM_2.5 whose concentrations in winter were significantly higher than those in spring. It indicates that coal heating during winter makes great contributions to the polluting elements in atmosphere and the main polluting particulates are Cd, As and Hg.     

北京市西北城区大气可吸入颗粒物中饱和烃的分布特征

利用气相色谱、气相色谱-质谱分析法从北京市西北城区四个季节大气可吸入颗粒物（PM10）中检测出种类丰富的饱和烃,主要包括正构烷烃、萜烷及甾烷等系列化合物。利用饱和烃的多项参数（如主峰碳数、碳优势指数CPI、藿烷22S/(22S+22R)比值等）对大气PM10中可溶有机物的来源及分布作了探讨。北京市西北城区PM10中正构烷烃的主峰碳数均介于23和27之间,而CPI值介于1和3之间,表明北京市西北城区PM10中的饱和烃均不同程度地受到了高等植物等现代生物和化石燃料（石油、煤等）不完全燃烧产物两种来源的影响,其中在春、夏季以高等植物、花粉、微生物等生物来源占比重较大,而在秋、冬季,尤其在冬季,化石燃料的不完全燃烧造成的污染比较明显。萜烷类物质的检出,表明北京市西北城区四个季节PM10中部分饱和烃来自于石油等化石燃料的不完全燃烧。甾烷类物质的检出,表明北京市西北城区四个季节PM10中部分饱和烃是来自于车辆释放的机油等。     

Characterization of ambient aerosols in Northern Thailand and their probable sources

The present study examines variation of ambient aerosol mass and number concentrations in Chiang Mai, Thailand during winter. Aerosol particle samples were collected and measured at four different sites, representative of urban, industrial, residential and rural areas during daytime between December 2003 and January 2004. Average 10 h particulate matter (PM) mass concentrations were found to be in the range of 75–290 ì g/m³, with average value of 149 ± 45 ì g/m³. Urban and industrial areas appeared to have higher PM loading than residential and rural areas. Number concentration and size distribution of particles in the range of 0.3–10.0 ìm did not exhibit any marked variation between sites. Relatively stable number concentrations were reported. Temporal variation of number concentrations was not clearly significant. No short term peak observed during rush hours. During sampling period, the average number concentration for 0.3–0.5, 0.5–1.0, 1.0–5.0 and 5.0–10.0 ìm were 6.60 × 10⁶, 1.18 × 10⁶, 2.11 × 10⁵ and 1.12 × 10⁴/m³, respectively. Particles with diameter smaller than 1.0 ìm accounted for over 90 % of the total number concentration. Concentrations of major metals were determined by atomic absorption spectrophotometer (Pb, Fe, Al, Si, Cr, Cd, Ni, Zn) and flame photometer (K, Na and Ca). Data obtained were used to identify probable sources via a multivariate analysis. Si, Na, Fe, Ca, Al and K were the six dominant elements in the airborne PM. Principle component analysis was carried out and major sources of airborne PM in Chiang Mai were determined, namely, (1) long distance sources such as sea spray, earth soil and industrial combustion, (2) short-distance sources such as crustal re-suspension, vehicular related emissions and vegetation burning, and (3) the unknown distance sources with low influence of traffic emissions.     

X-ray Diffraction of Dust Particles in Spring Beijing

X-ray diffractometry was utilized to study the mineralogical characteristics of the inhalable particles (PM10) sampled during two dust storms in Beijing city on March 18th and May 21st, 2008. We confirm, for the first time, that there stably exists ammonium chloride in the atmosphere when temperature is low. The total sulfates particles were affected by relative humidity. Both species and concentration of sulfates decreased first and then grew back by the end of each dust storm. Koninckite, a phosphate mineral never reported as particulate aerosol before, was identified. Meanwhile, our result shows that a chemical modification on dust minerals occurs during long range transportation. PM10 samples collected during the period of dust storms were dominated by crustal minerals such as quartz, illite/ smectite, illite, chlorite, feldspar and calcite, and were notably higher in concentration than that in normal periods of time. The amounts of total sulfates, calcite and feldspar altered in each dust storm. It is derived from 24-hour isentropic backward trajectories that two dust events in spring 2008 originated in different sources.     

兰州市城关区采暖期大气PM2.5成份分析及对子代小鼠的影响研究

为了解兰州市采暖期大气PM_2.5污染情况及其主要重金属和多环芳烃（PAHs）含量,并同时研究其对小鼠胎儿出生质量的影响,对兰州市城关区2015年11月至2016年3月大气PM_2.5进行重金属元素和PAHs的成份分析,同时将处理好的PM_2.5通过气管滴注对30只成功受孕10d的昆明小鼠（随机分成4个剂量组,每组6只）进行染毒（PM_2.5剂量：0、50、100、200μg·ml^-1·d^-1）,直到子鼠出生,分析窝产仔量和子鼠体重、心体比、肺体比等指标进而对子鼠出生质量进行评估。结果表明,兰州市城关区2015年采暖期大气PM_2.5总日均浓度符合国家标准,但有48d超过国家标准,最高浓度达到151μg·m^-3,主要的重金属和PAHs分别为铅和萤蒽。动物实验结果表明,PM_2.5染毒剂量越高,子鼠体重越轻,下降的幅度越大。与零剂量组比较,PM_2.5剂量组子鼠的心体系数和肺体系数显著降低,但窝产仔量和性别无明显差异。这表明采暖期大气PM_2.5可能会对妊娠期雌鼠产生作用,影响子代小鼠的出生质量和发育情况,这或许与其重金属和PAHs成分有关。     

北京市大气可吸入颗粒物的化学成分和来源

2007年3月至2008年5月,在北京市成府路东口设立采样点,共采集监测周期为一周的PM2.5(直径小于2.5μm的大气可吸入颗粒物)样品56个,用HR-ICP-MS方法测量了15种元素的含量,并在此基础上应用主因子分析法对PM2.5中这些元素的来源进行探讨。同时,在2008年奥运会和残奥会期间开展了24h时间间隔的密集采样,特别分析了机动车限行期间细颗粒污染物的浓度特征。结果表明,2007年春季至2008年春季期间北京市大气PM2.5平均浓度为72.9μg/m3,超过美国环保局（USEPA）制定的PM2.5年平均浓度限值15μg/m3的近5倍。机动车限行期间北京成府路东口采样点大气PM2.5的平均浓度为40.7μg/m3。通过因子分析方法确定北京PM2.5的3种可能来源：①交通排放、工业排放和燃煤,特征元素为Cu、Zn、As、Sn、Sb、Cd、Pb;②本地扬尘和远源沙尘细颗粒;③可能与成土母岩风化有关的土壤颗粒的再悬浮和/或迁移,其方差贡献率分别为41.2%、31.4%和12.2%。