飘散致敏花粉与大气颗粒物研究进展

大气颗粒物污染已经成为对中国环境质量影响的一大关键因素,调查显示,全世界约有11亿多的人口正遭受着大气污染的侵害。城市化进程的推进,使人群过敏和花粉污染现象日趋严重,花粉颗粒能够粘附大气颗粒物并与颗粒物产生交互作用,从而导致花粉致敏性加强。大气颗粒物复杂的组分加之特殊的粒径尺寸,人群很容易经呼吸道吸入这些大气细/超细颗粒物,对呼吸系统造成严重的氧化损伤,进而影响健康。鉴于飞散花粉和颗粒物危害极大,但其具体协同作用机制尚不明确,该文就国内外目前的研究现状做一总结,为进一步开展相关实验提供参考。     

济南地区春季大气中细颗粒物分布状况及形态的透射电镜实验研究

利用透射电镜观察分析了济南地区春季大气中细颗粒物显微形态及粒径分布状况,利用统计回归分析方法绘制了细颗粒物粒径与数量分布状况关系曲线及相应的柱状图.每例样品的采样时间为24小时,连续十天采样,统计分析结果表明:大气中细颗粒物粒径主要分布在0 μm～1μm范围之间,其次为1μm～2μm之间,实验结果对于研究大气中PM2.5及大气污染状况具有一定的参考价值,实验方法值得推广应用.     

上海市大气颗粒物中有机碳（OC）与元素碳（EC）的粒径分布

分析了上海市嘉定区不同粒径大气颗粒物(0.49、0.49～0.95、0.95～1.50、1.50～3.00、3.00～7.20、7.20μm)中OC和EC质量浓度的粒径分布特征;讨论了不同粒径大气颗粒物中二次有机碳EC示踪法中(OC/EC)pri的选定方法,用改进后的EC示踪法估算出上海市嘉定区大气颗粒物中的二次有机碳(SOC)质量浓度的粒径分布;通过OC和EC的相关性定性分析了上海市嘉定区大气颗粒物的主要来源.上海市嘉定区大气颗粒物中OC和SOC的质量浓度呈双峰分布,峰值出现在0.49μm与3.00μm的粒径段,EC出现双峰或三峰分布,与OC相比,更集中在0.49μm的粒径段.细颗粒(3.00μm)中OC和EC分别占总OC和EC质量浓度的59.8%～80.0%和58.1%～82.4%,OC和EC的质量浓度主要集中在3.00μm的颗粒物中.不同粒径颗粒物中SOC占相应粒径段内OC浓度的15.7%～79.1%,其中细颗粒物(3.00μm)和粗颗粒物(3.00μm)中SOC质量浓度占相应粒径段中OC的41.4%和43.5%.OC、EC和SOC的粒径分布显现出明显的时间依存性.OC和EC的相关性分析表明,上海嘉定区大气颗粒物的污染源主要以轻型汽油车尾气为主.     

南京北郊大气颗粒物的粒径分布及其影响因素分析

在南京北郊使用FA-3型9级采样器对2014年1~11月颗粒物的粒径分布进行了采样分析.首先将FA-3与中流量分级采样器(KC-120H)和环境保护局在线监测仪器的同期监测结果进行对比,数据相关系数均在0.95以上,对细粒子FA-3分别偏低13.9%和16.6%,而对PM_(10)偏高15.2%和13.3%,但采样偏差在大气采样可接受范围之内,说明其可以对大气颗粒物进行准确分级和采样.南京北郊颗粒物污染严重,PM_(1.1),PM_(2.1)和PM_(10)的年平均浓度分别为(65.6±37.6)、(91.0±54.7)和(168.0±87.0)μg·m-3,污染以细粒子为主,且大部分在1.1μm以下;颗粒物粒径呈双峰分布,峰值位于0.43~0.65μm和9~10μm粒径段;中值粒径为1.83μm,为积聚模态污染.颗粒物粒径分布在冬季细粒径段较高,春季粗粒径段较高,夏季细粒径段降低并不明显,粗粒径段明显低于其他季节;颗粒物浓度的昼夜变化在粗粒径段差异很小,在细粒径段基本表现出夜晚大于白天的特征.除了夏季,降水对各个粒径范围的颗粒物都有清除作用,且在细粒径段表现得更为明显;霾发生时随着霾等级的加重,0.43~2.1μm粒径段颗粒物浓度逐渐增加,该粒径段颗粒物质量浓度与能见度呈显著负相关.以相对湿度70%为界,颗粒物粒径分布发生了明显变化,湿度大于70%后,小于0.43μm粒径段颗粒物质量浓度显著降低,而0.43~2.1μm粒径段明显上升,颗粒物的吸湿增长应是主要原因.南京北郊的气团来源可以分为四类,其中西北方向快速输送的气团最为洁净,细粒径颗粒物浓度明显低于其它方向;本地和周边近距离输送的气团污染最重,粗细粒径颗粒物浓度都较高,其传输距离短,风速小,发生污染的概率最大,达到73.9%,对南京市的空气污染贡献较大.     

纳米颗粒物采样技术及其在大气监测中的应用

细粒径的颗粒物、尤其是空气动力学粒径1.0μm以下的纳米颗粒物是导致灰霾天气的主要原因之一.日本专利技术"纳米颗粒物采样系统"利用惯性纤维过滤分级纳米颗粒物,用一套系统实现对大气颗粒物在全粒径范围内的同步、连续分级监测,可同时获得多个粒径范围的颗粒物浓度和颗粒物化学成分含量,应用表明,该技术特点鲜明,在大气复合污染监测研究领域具有推广价值.     

上海工业区大气颗粒物中硫的化学形态和分布

用低压冲击式采样器 (DLPI) 采集了上海工业区和郊区大气中28nm~9.92μm粒径范围的颗粒物样品,用同步辐射X射线吸收近边结构谱(XANES)和X射线荧光分析(SRXRF) 对样品中硫的化学形态和含量进行了研究.结果表明,粗颗粒物和细颗粒物中的硫,大部分以硫酸盐形式存在;超细颗粒物中除了硫酸盐硫之外,一部分硫以低价的还原态形式存在,可能的化学形态为金属硫化物、噻吩类有机硫化物.细粒子中硫的质量浓度高于粗颗粒,约 70%的硫分布在细粒子中.硫的质量浓度呈多模态分布.工业区的超细颗粒物峰值出现在0.091~0.154μm;细颗粒的分布为积聚模,峰值出现在0.38~0.611μm;粗颗粒分布为粗模态,在1.59~3.98μm和6.57~9.92μm出现2个峰值.郊区的超细颗粒物中硫的质量分布不存在峰值;积聚模出现两个亚模态,分别为峰值在0.261~0.380μm的“凝结模态”和峰值在0.611~0.945μm的“液滴模态”;粗模态峰值在2.38~6.57μm.污染来源和颗粒物形成、转换机制以及不同采样时间的气象条件差异决定了2个地区颗粒物中硫的分布特性,工业区颗粒物中硫的来源有海盐源的贡献,而郊区较少受海洋源的影响.     

杭州市大气颗粒物浓度及组分的粒径分布

分别于2008年11月及2009年4~5月及10月采集了杭州大气颗粒物样本,测定了杭州市大气颗粒物及其化学组分[元素碳(EC)/有机碳(OC)、11种水溶性离子、20种元素]的浓度,并研究了其粒径分布特征.结果表明,杭州市大气颗粒物质量浓度、EC和OC的质量浓度、9种离子(SO42-、NO3-、K+、Na+、Cl-、Ca2+、Mg2+、NO2-、F-)浓度的粒径分布均显双峰结构,峰值分别出现在<0.49μm的细粒径段与3.00~7.20 μm的粗粒径段; OC、EC、SO42-、NO3-、NH4+以及主要来自人为源的元素(Cu、Zn、As、Se、Sb、Cd)主要集中在<3.0μm的细颗粒物中;杭州市大气细颗粒物中二次污染严重,细颗粒物主要受工业、交通等人为源影响.     

霾与非霾期间汞在不同粒径颗粒物上的分布特征

在我国高速经济增长过程中,霾污染日趋突出,同时大气汞污染也十分严重,而颗粒汞对于汞在大气中的循环演化意义重大.为了探讨霾污染期间汞在不同粒径颗粒物中的分布特征,采用Nano-moudi 12级(6.2~9.9μm、3.1~6.2μm,1.8~3.1μm、1.0~1.8μm、0.56~1.0μm、0.32~0.56μm、0.18~0.32μm、0.10~0.18μm,0.056~0.10μm、0.032~0.056μm、0.018~0.032μm、0.010~0.018μm)大气颗粒物采样器,对上海霾与非霾期间不同粒径大气颗粒物中的汞进行分析.结果表明,颗粒态汞含量与颗粒物含量正相关;采样期间霾天颗粒态汞平均浓度0.31 ng·m-3是非霾天颗粒态汞平均浓度0.11 ng·m-3的2~3倍;霾和非霾天颗粒态汞浓度以及颗粒物质量浓度随粒径分布呈双峰型,霾期间峰值分别出现在0.56~1.0μm粒径段和3.1~6.2μm粒径段,而非霾期峰值分别出现在0.32~0.56μm和3.1~6.2μm粒径段;霾天较非霾天颗粒态汞和颗粒物的粒径分布均出现了向大粒径方向偏移;颗粒态汞主要分布在粒径≤1μm粒子上,能够长时间停留和长距离输送;非霾期间颗粒态汞在颗粒物中的平均含量为0.029 ng·μg-1,而霾期间为0.015 ng·μg-1;霾污染过程中其他污染物迅速成长,而汞成长较慢;霾天积聚核模态粒子中颗粒态汞质量浓度为2.06 ng·m-3,而非霾天为0.55 ng·m-3,积聚态颗粒物的大幅增加,是灰霾形成的主要原因.本地源燃煤等的排放以及风沙扬尘的增加和外地源的输送是导致霾天污染严重的重要原因.     

石家庄地区大气细粒子增长特征初步研究

为研究石家庄地区大气细粒子的微物理特征,2010年5月在石家庄市气象局观测站,对大气颗粒物、NOx和SO2进行了外场观测.结果表明:石家庄地区粒径小于1.0μm的大气颗粒物中,0.01~0.1μm粒径范围的粒子所占比例高达89.3%,大气细粒子污染较为严重.0.01~0.02μm和0.02~0.1μm粒径范围的颗粒物具有大致相似的变化规律,且与0.1~1.0μm粒径范围的粒子数浓度变化趋势明显不同.通过对典型粒子增长事件的研究发现,0.01~0.02μm的粒子数浓度在上午8:00左右会急剧升高,并达到全天的最大值.其后,0.01~0.02μm的颗粒物粒径会不断增长,由于增长消耗,其数浓度会迅速下降,使得0.02~0.04μm的粒子数浓度在上午12:00前会迅速升高.通过对气象要素和污染气体的分析,发现在相对湿度较低、风速风向变化不大,太阳辐射增加的情况下,SO2气相成核参与颗粒物增长的可能性较大.     

南京江北新区大气颗粒物化学组分的粒径分布特征

为探究南京江北新区大气颗粒物化学组分的污染特征,于2013～2014年进行了分级颗粒物样品的采集,开展了颗粒物化学组分的粒径分布和季节变化研究.结果表明,细粒径段的9种水溶性离子总浓度在秋冬季高于春夏季,而粗粒径段冬季最高.冬季颗粒物中[NO^-₃]/[SO₄^2-]在粗粒径段最低;春、夏和秋季其粒径分布趋势一致.水溶性离子均呈双峰型分布, 4个季节的NO^-₃均在0.65～1.1μm出现峰值;夏秋季细粒径段的SO₄^2-于0.43～0.65μm出现峰值,冬季峰值位置向更粗粒子的方向移动;而Na⁺和Cl^-主要存在于粗粒子中.由阴阳离子电荷当量表明,大气粗、细粒子分别呈碱性和弱碱性.有机碳(OC)和元素碳(EC)主要存在于细粒径段,均呈双峰型分布;秋冬季细粒径段中的二次有机碳(SOC)远高于春夏季.由比值判断法进一步表明,南京江北新区颗粒物中的碳质组分主要来源于燃煤和生物质燃烧排...     

Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere

Ambient coarse particles (diameter 1.8-10 μm), fine particles (diameter 0.1-1.8 μm), and ultrafine particles (diameter < 0.1 μm) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 ± 2.18, 8.82 ± 3.52, and 2.02 ± 0.41 μg/m³, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.     

上海大气超细颗粒物和工业纳米颗粒的表征及细胞毒性的比较研究

采集了上海市石洞口地区2010年春季不同粒径大气颗粒物样品,使用ICP-AES和FESEM技术分析了颗粒物的化学组成和微观特征,比较了不同粒径的大气颗粒物与3种工业纳米颗粒物的生物活性.结果表明,在染毒剂量为25、50、100和200μg.mL-1时,大气颗粒物水溶组分和不溶组分及工业纳米颗粒均可以抑制A549细胞生长活性并能诱导细胞产生活性氧(ROS),且大气细颗粒水溶组分生物活性最强,在上述染毒剂量下对细胞生长活性的抑制率分别达到13.31%、18.15%、20.43%和23.78%.在纳米尺度的颗粒物染毒组分中,纳米NiO的生物活性最强,在上述染毒剂量下对细胞生长活性的抑制率分别达到11.81%、15.12%、17.62%和19.44%.因此,大气细颗粒物水溶组分是最主要的毒性成分.     

隧道大气细颗粒物及其元素的粒径分布特征

对比研究了隧道和大气环境中不同粒径细颗粒物 (切割粒径分别为0.03,0.06,0.108,0.17,0.26,0.40,0.65,1.0,1.6和2.5 μm) 中S,K,Ca,Ti,Mn,Fe,Zn,Pb,Al,Si,Cu和V等12种痕量元素的浓度. 结果表明:隧道中不同粒径细颗粒物的数浓度和质量浓度在上下班高峰时段出现明显峰值,且隧道细颗粒物在0.108 μm粒径处的数浓度和在2.5 μm粒径处的质量浓度分别是大气环境对照值的15.2和40.0倍;在隧道传输过程中质量浓度增加的痕量元素有 Si,Ca,Fe,Al,Ti,Zn,Mn,Cu和V,减小的有S,Pb,Zn和K;地壳元素(Si,Ca,Fe,Al和Ti)的质量浓度总和占隧道细颗粒物中痕量元素质量浓度总和的87%,表明土壤扬尘仍是隧道大气细颗粒物的主要来源.      

上海大气中花粉与颗粒物的复合污染特征

于2009~2010年,利用风标式花粉采集器,采集了上海不同区域春、秋、冬季的飞散花粉和大气颗粒物样品,并于春季(2010年4月)利用重力花粉采集器在不同高度采集了飞散花粉样品,以及不同区域悬铃木的花粉.对风标花粉采样器采集的样品进行溶酸处理后进行花粉鉴定;对重力法采集的花粉样品染色后直接进行观察.利用高分辨的扫描电镜(SEM)对悬铃木花粉上吸附的大气颗粒物进行了微观表征.结果显示,上海春季大气中的花粉以木本植物花粉为主.不同区域悬铃木花粉上所吸附的颗粒物组分有所差异.冬季和春季大气颗粒物(总悬浮颗粒物)中的SO42-的浓度均为所检测离子(Na+、K+、Ca2+、Mg2+、NH4+、NO3-、SO42-、Cl-)中浓度最高的,NO3-、SO42-、NH4+在冬季样品中要比春季样品中的浓度高.上海大气颗粒物中的地壳元素的质量浓度从高到低为Ca >Na>Mg>K.     

Oxidative capacities of size-segregated haze particles in a residential area of Beijing

The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental efects on visibility and public health. To discover the potential health efects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements(As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, Tl, and Zn) in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the watersoluble trace elements were found to mainly concentrate in the fine particle size of 0.56–1.0 μm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.     

Studies on relationships between air pollutants and allergenicity of Humulus Scandens pollen collected from different areas of Shanghai

Pollen pollution and allergy are becoming prominent issues in China. However, few studies on pollinosis have been reported. As an allergen in the atmosphere, allergenic Humulus scandens pollen was collected from four districts of Shanghai, including Wusong (WS), Jiading (JD), Xujiahui (XJH) and Songjiang (SJ). The mass concentrations of SO₂, NO₂, O₃, PM_10, and PM_2.5 (particulate matter with air dynamic diameter less than 10 and 2.5 µm, respectively) near the four sampling sites were also recorded during Humulus scandens pollen season. The allergenicity of the Humulus scandens pollen was assessed by using of a rat model and enzyme linked immunosorbent assay (ELISA). Relationships between the allergenicity and air pollutants were correlated. Our results demonstrated that the biological viability of the pollens collected from the four districts exhibited no significant differences. ELISA and dot blotting results further demonstrated that the serum of sensitized rats exhibited much higher immune-reactive response than that of control groups. Western blotting showed that the 15 KD (1KD = 1000 dalton) proteins of Humulus pollen led to the allergic response. The allergenic intensity of Humulus pollen protein from different samples followed the pattern: WS > JD > XJ > SJ. There was a negative relationship between the allergenicity of Humulus pollens and PM₁₀ (R = -0.99) / PM_2.5 (R = -0.73), and a positive relationship with O₃ (R = 0.92). These data clearly showed that PM₁₀ and PM_2.5 could enhance Humulus pollen protein release, and O₃ could aggravate the allergenicity of the Humulus pollen.     

Sources and characteristics of the atmospheric aerosol near Damascus,Syria

Coarse (>2 μm) and fine (<2 μm) atmospheric particulate material was collected in the Zabadani Valley, near Damascus, in August 1985, and analyzed for sulfate, nitrate, and about 40 elements. Individual particles were analyzed for chemical and morphological parameters. Particle number concentrations and size distributions were also measured. The physical aerosol characteristics, and particularly the chemical composition indicate that the airborne particles in this arid region are predominantly due to desert soil dispersion, but that there is also some contribution from anthropogenic sources. The crustal elements exhibit atmospheric concentrations which are comparable to those in urban and industrial areas. The anthropogenic elements, on the other hand, are clearly less abundant in the Zabadani Valley than in industrialized regions. The individual particle analysis indicated that there are two major soil dust components with respectively a shale-like and a limestone composition. The data set with the bulk atmospheric concentrations (sum of coarse and fine) was subjected to chemical mass balance receptor modeling in order to assess the impact of the various plausible aerosol sources. It was found that desert soil dispersion is responsible for at least 90% of the total suspended particulate mass concentration, and that the shale and limestone components contribute in about equal proportions.     

不同粒径大气颗粒物中多环芳烃的含量及分布特征

采集了北京城乡结合部与郊区2003年4个季节的不同粒径大气颗粒物样品 ,运用GC/MS分析了其多环芳烃组成 .结果表明 ,17种PAHs总量为 0.84～15.223ng/m³,城乡结合部含量是郊区的1.07～6.60倍 .PAHs总量的季节性变化表现为冬季>秋季>春季>夏季,且随颗粒物粒径减小,含量逐渐增大,大约有68.4%～84.7%的PAHs吸附在≤2.0μm颗粒上.2～3环PAHs呈双峰型分布,4～6环PAHs呈单峰型分布 ,PAHs分子量越大 ,MMD值越小 ,燃煤取暖与低温是导致冬季PAHs污染增高的主要因素.     

上海市PM2.5的物理化学特征及其生物活性研究

采集了上海市区和郊区春季和夏季的大气PM_2.5样品,分析了市区和郊区春夏2季PM_2.5质量浓度变化的规律,使用PIXE(Proton Induced X-ray Emission)分析技术获得S、K、Ca、Ti、Cr、Mn、Fe、Ni、Cu、Zn、As、Se、Br、Sr、Pb等15种元素的质量浓度.结果表明,上海PM_2.5中化学元素的质量浓度在春季　(5?038.6 ng·m^-3) 比在夏季 (3?810.6 ng·m^-3) 高,春季郊区(2?528.9 ng·m^-3) 和市区(2?509.7 ng·m^-3) PM_2.5中化学元素的质量浓度相当,夏季市区样品 (1?674.2 ng·m^-3) 中化学元素质量浓度的总量比郊区(2?136.3 ng·m^-3) 的低,但来自人为污染的化学元素 (Cr、Mn、Ti、Ni、Cu、Zn、As、Br、Sr、Pb) 在市区PM_2.5中的含量较高;场发射扫描电镜 (FESEM) 分析显示,上海PM_2.5主要由烟尘集合体、燃煤飞灰、矿物颗粒、生物质颗粒和不明物质组成,质粒DNA评价揭示上海市区PM_2.5比郊区的具有更强的生物活性,主要原因可能在于市区样品中含有较高的重金属元素和较多的烟尘集合体．     

上海城区和临安本底站PM_(2.5)的物化特征及来源解析

2008年4月在上海城区(徐家汇)和浙江临安大气污染本底站2个地区同步采集PM2.5样品,利用场发射扫描电镜(FESEM/EDS)和同步辐射相关技术对两地PM2.5的微观形貌、化学元素组成及来源,以及重金属元素Zn的价态进行了分析.结果表明,徐家汇、临安的PM2.5平均质量浓度分别为(131.6±65.2),(83.5±22.9)μg/m3.徐家汇地区PM2.5主要由烟尘、飞灰、矿物质等组成;临安地区PM2.5中主要为不规则形貌颗粒物.上海城区PM2.5中重金属元素的浓度明显高于临安地区样品.同步辐射X射线吸收近边结构谱的结果显示,两地PM2.5中的Zn元素都以ZnSO4为主要存在形式.富集因子法分析19种元素中,除K、Ca外,其他元素在PM2.5中富集程度上海均高于临安地区.