北京西北城区与清洁对照点夏季大气PM_(10)的微观特征及粒度分布

应用高分辨率场发射扫描电镜 (FESEM )和图像分析技术研究了北京西北城区和清洁对照点非取暖期(2 0 0 1年夏季 )大气单个颗粒物的形貌特征以及PM10 和PM2 5的数量 粒度和体积 粒度分布 .研究表明 ,烟尘集合体在 2个采样点都普遍存在 ,具有区域性污染的特征 ;不规则状矿物颗粒物多见于市区PM10 样品中 ,而长条状石膏颗粒多出现在清洁对照点颗粒物样品中 ;在清洁对照点还观察到了生物质颗粒 .PM10 的数量 粒度分布呈双峰分布 ,主峰为 0 2～ 0 5 μm ,次峰为在 1～ 2 5 μm .但PM10 的体积 粒度分布呈单峰分布 ,在 1～ 2 5 μm粒度范围内 .综合分析得出 ,虽然粗颗粒 ,主要是矿物颗粒 ,在数量上对PM10 贡献很小 ,但是对总体积 ,因此对总质量的贡献可能很大 .但在PM2 5中 。

可吸入颗粒物PM_(10)对细胞间隙连接通讯的抑制作用

[目的 ]研究直径≤ 1 0 μm的可吸入大气颗粒物 (PM1 0 )对细胞间隙连接通讯的影响 ,探讨PM1 0 的非遗传毒性作用。 [方法 ]用大流量采样器 ,采集城区交通干道旁约 1 8m高度处大气中的PM1 0 。超纯水超声提取、低温真空冷冻干燥制备PM1 0 悬液。采用细胞代谢协同试验和染料划痕试验观察PM1 0 对中国仓鼠肺成纤维V79细胞以及人肺成纤维细胞间隙连接通讯的影响。 [结果 ]PM1 0 抑制V79细胞的代谢协同作用 ,使V79- 细胞的存活率增高 ,在 1 0～ 1 0 0mg/L剂量范围内 ,与对照组比较 ,克隆形成数明显增高 ,有剂量 反应关系 (r=0 94,P <0 0 5)。细胞划痕实验结果显示 ,在PM1 01 0～ 1 0 0mg/L剂量范围内 ,在人肺成纤维细胞中荧光染料扩散距离随剂量的增加而减小 (7 5～ 2 1 61mm) ,与对照组(2 6 56mm)比较 ,差异显著。 [结论 ]PM1 0 能抑制细胞间隙连接通讯 ,提示可能在癌症的发生过程中起促进作用。

可吸入颗粒物(PM_(10))空间特点与城市热岛格局的关系分析

采用成都市可吸入颗粒物(PM10)小时浓度的空间分布实例,结合NOAA/AVHRR(National Oceanic and Atmospheric Administration/Advanced Very High Resolution Radiometer)遥感数据所获的城市热岛温度场格局图,结果发现:下午环形热岛出现时城市中心区的PM10浓度较低,二、三环路附近的浓度相对较高,城区西南部尤其明显。分析认为,环形热岛改变了城市近地层的温度场和流场结构,在城郊结合部造成"双重循环",容易导致污染物在这些地方聚集。

Mineralogical characterization of airborne individual particulates in Beijing PM10

This work mainly focuses on the mineralogical study of particulate matter（PM10） in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray（SEM/EDX） was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc（ZnCl2） were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.

Chemistry and particle size distribution of respirable coal dust in underground mines in Central Eastern Europe

Despite international efforts to limit worker exposure to coal dust,it continues to impact the health of thousands of miners across Europe.Airborne coal dust has been studied to improve risk models and its control to protect workers.Particle size distribution analyses shows that using spraying systems to suppress airborne dusts can reduce particulate matter concentrations and that coals with higher ash yields produce finer dust.There are marked chemical differences between parent coals and relatively coarse deposited dusts(up to _(500)μm,DD_(500)).Enrichments in Ca,K,Ba,Se,Pb,Cr,Mo,Ni and especially As,Sn,Cu,Zn and Sb in the finest respirable dust fractions could originate from:(i)mechanical machinery wear;(ii)variations in coal mineralogy;(iii)coal fly ash used in shotcrete,and carbonates used to reduce the risk of explosions.Unusual enrichments in Ca in mine dusts are attributed to the use of such concrete,and elevated K to raised levels of phyllosilicate mineral matter.Sulphur concentrations are higher in the parent coal than in the DD_(500),probably due to relatively lower levels of organic matter.Mass concentrations of all elements observed in this study remained below occupational exposure limits.

Black Carbon Instead of Particle Mass Concentration as an Indicator for the Traffic Related Particles in the Brussels Capital Region

The Brussels Capital Region has difficulties in meeting the stringent EU daily limit value for PM10 in all its measuring sites. Postponing the attainment of the deadline was not granted by the EU Commission, mainly due to insufficient judged measures to reduce road traffic emissions. However, a thorough analysis of the data makes clear that neither the particle mass concentration (PM10 and PM2.5) nor the particle number concentration are specific metrics for evaluating the particle pollution originated by traffic. In fact, increased formation of secondary aerosol, together with adverse meteorological conditions and the (re) suspension of the coarser fraction are by far the three main explanations for the numerous PM10 exceeding values. From our experience, amongst the particles measured, only the results for Black Carbon (BC), mainly present in the lower submicron range, are reflective of the direct influence of local traffic. Measured at two traffic sites along with PM mass and number concentrations, the data for Black Carbon show a striking correlation with nitrogen monoxide, a parameter strongly related with the proximity of the local traffic. The correlation factor between Black Carbon data and NO or NOX is much higher than between Black Carbon and the PM mass or number concentration. Therefore the assessment of traffic related particles should consider Black Carbon rather than PM10 or PM2.5.

Source Apportionment of Ambient PM_(10) in the Urban Area of Longyan City,China:a Comparative Study Based on Chemical Mass Balance Model and Factor Analysis Method

In order to identify the day and night pollution sources of PM10 in ambient air in Longyan City,the authors analyzed the elemental composition of respirable particulate matters in the day and night ambient air samples and various pollution sources which were collected in January 2010 in Longyan with inductivity coupled plasma-mass spectrometry（ICP-MS）.Then chemical mass balance（CMB） model and factor analysis（FA） method were applied to comparatively study the inorganic components in the sources and receptor samples.The results of factor analysis show that the major sources were road dust,waste incineration and mixed sources which contained automobile exhaust,soil dust/secondary dust and coal dust during the daytime in Longyan City,China.There are two major sources of pollution which are soil dust and mixture sources of automobile exhaust and secondary dust during the night in Longyan.The results of CMB show that the major sources are secondary dust,automobile exhaust and road dust during the daytime in Longyan.The major sources are secondary dust,soil dust and automobile exhaust during the night in Longyan.The results of the two methods are similar to each other and the results will guide us to plan to control the PM10 pollution sources in Longyan.

Elemental Composition of PM2.5 and PM10 in the Industrial Area of Yopougon, Abidjan, Côte d’Ivoire

This paper describes the evaluation of trace element composition of atmospheric aerosol particles (PM2.5 and PM10) and their influence on air quality in the largest industrial area of Abidjan city, C?te d’Ivoire. Multi-week sampling was conducted in an urban site (industrial area) in Abidjan from April 2018 to July 2019. The mean mass concentration was 48.83 ± 15.24 μg/m3 for PM2.5 and 77.34 ± 10.91 μg/m3 for PM10, with significant temporal variability. The average ratio of PM2.5/PM10 was 0.64 ± 0.21. The concentration of BC in PM2.5 and PM10 was respectively 52.32 ± 7.48 μg/m3 and 52.26 ± 12.07 μg/m3. Twenty-two elements: Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Zr and Pb were analysed by Energy Dispersive X-ray Fluorescence (EDXRF). Elemental composition data were modeled using principal component analysis (PCA) with varimax rotation to determine two (2) and four (4) dominant source categories contributing to PM2.5 and PM10 respectively. In the case of fine particles PM2.5, the possible sources were Industrial activities and non-exhaust emissions, exhaust emissions. The PM10 sources were industrial activities and non-exhaust emissions, industrial processes, mineral dust, and waste combustion.

Incense smoke(IS)inhalation exposure system:Physicochemical characterization,IS particle deposition and clearance in human airway using MPPD model

Incense smoke(IS)is source of indoor air pollution and key risk for diverse human diseases.Less in-formation is available regarding controlled IS rodent inhalation exposure system and IS particulate matter(PM)deposition in human airways.Study aimed to demonstrate stable ISPM physicochemical parameters of 10 incense products inside the customized whole body inhalation exposure chamber(without animal)connected to smoke generation unit via aerosol mixing device.IS analyzed for size segregated PM emission,ISPM in vitro aerodynamics(MMAD and GSD determination),fine and ultrafine particle's SEM,SEM-EDX and PAH analysis.Using real life exposure scenario by utilizing MMAD,GSD and PM concentration after Tier 1 exposure assessment as key input parameters,ISPM dosimetry in infant(3 months)and adult(21 years male and female)human airways was calculated using multiple-path particle dosimetry(MPPD 3.04)modeling.Mass median aerodynamic diameter(MMAD)and geo-metric standard deviation(GSD)ranged between 0.55 and 2.10μm and 1.22 to 1.77(polydisperse)respectively.PM1.0 and PM0.1 showed multiple morphology and presence of heavy and trace elements.PAH like acenaphthylene,anthracene,fluorene,naphthalene and phenanthrene were detected(0.84-143.17μg/g).MPPD results showed higher ISPM deposition in pulmonary region and lowest in trachea bronchial region.ISPM deposition in tissue was higher in lower,peripheral lung as compared to upper and central lung tissue.Whole body inhalation exposure system showed stable IS atmosphere(physi-cochemical parameters)indicating the device suitability in future inhalation studies.MPPD ISPM deposition fraction and clearance data showed deep lung penetrating and retention behavior with higher risk in infant followed by female and then male.These modeled particle deposition and clearance data may be useful in risk assessment analysis of IS.

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 2 2S/(2 2S +2 2R)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 2 3和 2 7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。

北京市不同尺度大气颗粒物元素组成的特征分析

在 2 0 0 0年 2个典型季节分别采集不同尺度的颗粒物样品 ,分析其中 2 2种无机元素的含量。利用这些数据较详细地研究了北京市颗粒物的元素组成特征。数据分析结果表明 ,北京市大气颗粒物中的元素主要分为地壳元素、污染元素和双重元素三大类。利用不同污染元素在各种尺度颗粒物中的富集因子 。

沙尘天气对我国城市空气质量影响的范围与强度分析

近年来 ,可吸入颗粒物已成为影响我国城市空气质量的首要污染物。该文分析了城市中颗粒物的不同来源 ,根据对沙尘天气的发生过程监测 ,结合我国重点城市空气质量统计数据 ,提出了沙尘影响指数的概念。根据沙尘影响指数对不同类型城市空气中的可吸入颗粒物来源和沙尘影响程度进行了分析 ,力求明确沙尘天气与空气质量的关系。根据 2 0 0 1年和 2 0 0 2年 3月最新的沙尘天气监测数据和特定的沙尘天气过程 ,按照沙尘来源和沙尘影响范围将沙尘影响地区进行了分区 ,分析不同区域内的起沙机制和沙尘来源 。

HEPA空气净化器对学校室内颗粒物的净化效果研究

为了解HEPA(high efficiency particle air filter,高效空气过滤器)空气净化器在小学教室和寝室的净化效果,于2019年3—4月在北京市一所全寄宿小学开展了一项HEPA空气净化器的交叉干预研究.记录干预组、非干预组室内和室外PM2.5、PM 10、PM 1的浓度,计算空气净化器的净化率;采用多元线性回归模型探索净化效果的影响因素.结果表明:①空气净化器对PM2.5、PM 10、PM 1的净化率分别为41.3%[Q 1~Q u(下四分位数~上四分位数,下同):0~53.1%]、40.7%(10.5%~46.2%)和34.9%(9.6%~40.3%),其中对PM2.5的净化率最高;寝室的净化率高于教室的净化率.②当室外PM2.5浓度为[115,150)μg/m^3时对PM2.5的净化率最高,为52.83%(50.26%~56.13%),PM 10和PM 1亦有类似结果.③多元线性回归分析表明,室外PM2.5浓度<35μg/m^3时,开门通风和室内人员活动分别使室内PM2.5浓度下降3.73μg/m^3〔95%置信区间(95%CI):(0.60μg/m^3,6.86μg/m^3)〕和升高3.4μg/m^3(0.22μg/m^3,6.58μg/m^3);室外PM2.5浓度为[35,150)μg/m^3时,空气净化器使室内PM2.5浓度下降33.36μg/m^3(16.47μg/m^3,50.25μg/m^3);室外PM2.5浓度≥150μg/m^3时,空气净化器和开门通风分别使室内PM2.5浓度下降48.87μg/m^3(25.62μg/m^3,72.12μg/m^3)和升高37.65μg/m^3(5.60μg/m^3,69.69μg/m^3).研究显示:空气净化器可同时降低室内PM2.5、PM 10、PM 1的浓度;当室外PM2.5浓度<35μg/m^3时,不需开启空气净化器;当室外PM2.5浓度为[35,150)μg/m^3时,空气净化器有较好的净化效果,偶尔开窗通风不影响空气净化器的净化效果;当室外PM2.5浓度≥150μg/m^3时,开启空气净化器时应关闭门窗,以免影响其净化效果.

北京西北城区2002年春季大气可吸入颗粒物的粒度分布特征

本文应用高分辨率场发射扫描电镜(FESEM)获得北京西北城区2002年春季可吸入颗粒物显微形貌图片,并利用数字图像粒度分析系统得到可吸入颗粒物中烟尘集合体、燃煤飞灰、矿物等三种主要颗粒的数量-粒度分布数据。结果表明,北京市西北城区2002年春季可吸入颗粒物的粒径主要分布在1～2 5μm之间,其次在2 5～10μm之间,矿物颗粒占总颗粒数量的82 25%。对矿物颗粒的数量-粒度分布和体积-粒度分布进行对比表明,小于5μm的颗粒虽然在体积上只占20%,但在数量上却达90%。因为颗粒越细,其比表面积越大,吸附的有害物质也越多,所以细颗粒物今后应深入研究。

户外空气中可吸入颗粒物对出生体重的影响

目的研究空气污染物可吸入颗粒物(PM10)对新生儿出生体重的影响。方法利用某地所有助产机构的2003～2005年围产保健数据和2002～2005年该地区各空气污染监测点监测的每日可吸入颗粒物(PM10)浓度数据,根据末次月经和分娩日期计算每位产妇孕期暴露于可吸入颗粒物(PM10)的水平,从而分析孕期接触可吸入颗粒物(PM10)对新生儿出生体重的影响。结果不同的胎儿性别、母亲年龄、母亲职业、母亲原地址、孕期高危情况、孕次分组间出生体重有显著性差异;在不同孕期,<67.6μg/m3、67.6～162.4μg/m3和>162.4μg/m3的3个可吸入颗粒物(PM10)暴露组间出生体重有显著性差异。多元线性回归分析显示,可吸入颗粒物(PM10)的浓度每增加10μg/m3,新生儿出生体重会减少2.2～2.7g。结论影响新生儿出生体重的因素有很多,其中户外空气中较高可吸入颗粒物(PM10)污染是一个重要因素,与新生儿低出生体重有关。

大气气溶胶中铊污染问题的研究进展

铊(Tl)是典型的毒害重金属元素之一,也是我国《重金属污染综合防治"十二五"规划》兼顾防治的重金属污染物之一。铊对生物体的毒性大于铅、镉和汞等元素。大多数铊化合物的熔点、沸点较低,在含铊硫化物矿高温焙烧过程中易挥发,容易以气溶胶的形式通过炉气进入大气环境中。本文对近年来大气气溶胶中铊污染问题的研究现状和进展进行了总结评述。

大气可吸入颗粒物对环境和人体健康的危害

简要介绍了大气可吸入颗粒物PM10 (空气动力学直径小于或等于 10 (μm )的基本特性及污染现状。从能见度、温度、酸雨等方面 ,阐述了可吸入颗粒物对环境产生的严重影响 ;依据国内外流行病学研究的结果 ,概述了可吸入颗粒物对人体呼吸系统、心血管系统、神经系统、生殖系统等造成的较为广泛的损害。同时 ,也指出了我国进行大气可吸入颗粒物研究的意义。

对于我国环境空气颗粒物术语定名的建议

文章深入归纳了我国环境空气质量标准中颗粒物术语的演绎过程及主要国家、地区和组织颗粒物术语,提出了适用于我国的颗粒物术语建议:粒径小于等于10微米和粒径小于等于2.5微米颗粒物分别命名为颗粒物(粒径小于等于10微米)和颗粒物(粒径小于等于2.5微米),又分别称为可吸入颗粒物和细颗粒物,英文名称分别为particulate matter(PM10)和particulate matter(PM2.5)。

典型矿业城市大气颗粒物水溶性离子分布特征

利用2014年7月和2015年1月在淮南市不同功能区采集的大气颗粒物样品,分析其水溶性离子时空和粒径分布特征。结果表明:夏季和冬季粗、细粒子中总水溶性离子质量浓度均值分别为(13.45±4.53)μg/m^3、(27.81±17.65)μg/m^3和(12.87±8.37)μg/m^3、(85.08±35.41)μg/m^3。淮南市大气颗粒物中主要的水溶性离子为Ca^(2+)、NO^-_3和SO■。冬季各功能区PM_(2.5)中总水溶性离子质量浓度普遍高于夏季。大气颗粒物中水溶性离子主要来源于土壤源、工业污染及二次转化,冬季二次污染源主要以流动源污染为主,而夏季流动源和固定源污染贡献接近。

兰州市大气颗粒物污染特征分析

对兰州市2011—2012年大气颗粒物污染状况进行了研究,在主导风向上设置采样点,分别连续监测PM10、TSP、风速、能见度。结果表明,兰州市颗粒物浓度的峰值出现在2—4月,TSP浓度最大值可达到2.465 mg/m3,PM10最大值可达到2.079 mg/m3;颗粒物污染的季节性强,以3、4月出现的频率最高,发生时间具有随机性;2012年兰州市全年颗粒物(PM10和TSP)平均小时浓度值低于2011年,沙尘天气发生频次较2011年有所降低,环境空气质量有所改善。