北京市和南京市采暖期不同粒径大气颗粒物水溶性阴阳离子的比较研究

目的了解采暖期北京市和南京市大气颗粒物的粒径谱以及不同粒径颗粒物水溶性阴、阳离子浓度的差别。方法于2015年11月23日—2015年12月17日在北京市和南京市分别使用PSW-8型气溶胶粒度分布采样器采集大气颗粒物,并采用重量法和离子色谱法分别测定大气中颗粒物的浓度和不同粒径颗粒物水溶性阴阳离子的浓度。结果北京市大气颗粒物的总浓度高于南京市,且粒径小于2.1μm的颗粒物的质量占总颗粒物的比例均大于63.5%。除了Ca~(2+)的浓度,北京市大气颗粒物中F~-、Cl~-、SO_4~(2-)、NO_3~-、Na~+、NH_4~+、K~+和Mg~(2+)的浓度均高于南京市。大气颗粒物中NH_4~+、SO_4~(2-)和NO_3~-的含量较高,主要富集于粒径小于2.1μm的颗粒物中,Mg~(2+)、Ca~(2+)和F~-主要富集于粒径大于2.1μm的颗粒物中。北京市不同粒径颗粒物中NO_3~-和SO_4~(2-)的比值范围为0.75~1.01,南京市为1.20~1.55。结论采暖期两个城市大气颗粒物中水溶性离子的主要来源不同,两个城市水溶性离子在不同粒径颗粒物上分布规律一致。     

南京市某区大气颗粒物有害元素分布富集及风险特征

目的分析南京市某区大气颗粒物上负载重金属及类金属元素的浓度水平,评估分级粒径段颗粒物上负载元素成分特征及风险。方法运用PSW-8型气溶胶粒度分布采样器于2015年11月23日—12月17日采集南京市某区大气颗粒物样品,通过重量法测定不同粒径大气颗粒物的浓度,并基于微波消解-ICP/MS法测定不同粒径颗粒物中不同重金属及类金属元素的浓度,运用美国环保局推荐的环境健康风险评价模型对不同粒径颗粒物中重金属及类金属的健康风险进行评价。结果南京市某区大气颗粒物(0. 65~1. 1)μm粒径的质量浓度及质量均最高,(0. 43~10)μm全粒径大气颗粒物中各重金属及类金属元素浓度的趋势为:AlPbMnCuCrSrAsNiSeVRbCdBiUCoCsAg。Se、Pb、Ag、As、Bi、Cd、Cs、Rb、Ni、Cu、Cr、Mn和V共13种重金属及类金属元素主要集中分布于2. 1μm以下的颗粒物上,U、Co、Sr和Al 4种元素主要分布在2. 1μm的颗粒物中。U、Cr、Ni、Cu、Pb、As、Ag、Bi和Cd元素在各粒径段中的富集因子均10,其中粒径段越小的重金属及类金属元素富集因子越高。本研究各元素的非致癌风险1,细粒径段及全粒径段的多种元素致癌风险之和大于1. 00×10-6。结论南京市某区采样期内2. 1μm以下大气颗粒物占比较大,对人群健康影响较大的重金属及类金属元素在细粒径段的含量较高,细粒径段各元素的富集因子和健康风险更高。应加强大气颗粒物中细粒径颗粒物及其负载污染物的研究。     

太原市大气颗粒物浓度分布特征

目的研究大气中不同粒径颗粒物的百分比。方法采用CD-III型大流量冲击式采样器在重度污染区(A区)、中度污染区(B区)和相对清洁区(C区)。三个研究区分别采集采暖期和非采暖期的大气分级颗粒物样品,用重量法求出不同动力学粒径颗粒物的浓度分布。结果颗粒物污染水平A区>B区>C区;采暖期和非采暖期可吸入颗粒物(≤10μm)分别占总悬浮颗粒物的81%~86%和75%~78%;采暖期和非采暖期大气颗粒物质量中值直径(MMD)分别为0.45~0.62μm和1.6~2.2μm。结论同一研究区域采暖期颗粒物质量浓度明显高于非采暖期,且A区、B区明显高于C区;颗粒物浓度主要集中在对人体危害较大的0.5~5μm范围内;理论计算结果显示,太原市采暖期在成年人支气管和肺泡部位沉积的可吸入颗粒物是标准值状态下颗粒物沉积量的1.9~5.7和1.9~4.4倍。     

沈阳市大气悬浮颗粒物及PAHs、NPAHs分析

目的 调查了解沈阳市大气中悬浮颗粒物及其多环芳烃(PAHs)、硝基多环芳烃(NPAHs)的浓度、分布及季节变化情况。分析其健康效应。方法 选择沈阳市内机动车交通量有差别的3所小学校，于夏季非采暖期和冬季采暖期各监测1周，每天连续24h样。分别测定样品中PAHs、NPAHs种类与含量。结果 测定的10种PAHs主要以4个苯环的多环芳烃为主，即：Chr(Qu)、13aA(苯并a蒽)、Pyr(芘)、Flu(荧蒽)；测定11种NPAHs主要以2NP(夏季)、2-NF(冬季)为主，其中粒径在2．1μm以下的分别占71％，67％。夏季非采暖期以粒径0．7μm和5μm的粒子为主，冬季采暖期在机动车流量较低地区PAHs、NPAHs浓度大幅度升高，并以粒径2.1～7.0μm的颗粒物为主。结论 沈阳市大气中悬浮颗粒物及PAHs、NPAHs主要来源于冬季燃煤等污染，应进一步加以治理。     

多环芳烃在不同粒径大气颗粒物上的分布

目的 研究多环芳烃(PAHs)在冬季和夏季不同粒径大气颗粒物上的分布。方法 用DFJ-1型五段分级采样器采样,用GC-MS法测定,分析衡阳市区冬夏两季空气中PAHs在不同粒径颗粒物中的分布。结果 在大气颗粒物分级样品中,均检出PAHs。PAHs在冬夏两季空气中的浓度分别为161．42、140．72 ng／m^2,在粒径≤2．0μm的细小颗粒上的含量分别占总量的63．3％与52．3％。结论 衡阳市大气环境中PAHs的含量冬季明显高于夏季,冬季主要富集在粒径≤2.0μm的细小颗粒上,PAHs在不同粒径大气颗粒物上的分布不一致,夏季在粗细粒子中分布较为均匀,冬季PAHs的分布明显发生变化。     

东北3城市大气悬浮颗粒物浓度的季节变动与粒径分布

目的了解东北3个不同类型城市的大气悬浮颗粒污染物的浓度、分布及季节变化情况。方法选择沈阳市、抚顺市、铁岭市不同区域各3所小学及附近10户居民（距校址500 m以内）为监测点,分别于2002、2003、2004年每季监测2 w,每次48 h连续采样,重量法测定大气悬浮颗粒物浓度、粒径分布和季节变化情况。结果3城市监测点的大气悬浮颗粒物污染情况相近。大气悬浮颗粒物浓度3城市3年内的冬、春两季都超过国家环境空气质量二级标准1.28～1.54倍;PM10浓度3城市3年内各季节每次日采样测量均超过国家环境空气质量二级标准1.07～2.22倍;PM2.5浓度超过美国EPA细颗粒物空气质量标准3.84～7.76倍。结论采暖期大气悬浮颗粒物污染加重,非采暖期大气悬浮颗粒物增加与沙尘暴过境有关。其中抚顺市大气悬浮颗粒物污染加重与工矿企业污染有关。     

太原市室内外空气中颗粒物污染特征

目的研究太原市室内外空气颗粒物污染特征。方法于2004年4月-2006年10月在太原市21个社区541户家庭采用Aerocet531型粉尘仪-粒子计数器在采暖期和非采暖期测定室内外空气中PM1.0、PM2.5、PM7.0、PM10.0和TSP的浓度。应用Stata 9.0统计软件进行统计学分析。结果太原市空气污染最严重的社区室内、外TSP浓度分别为1 030.70和1 681.46μg/m3,采暖期与非采暖期比较,采暖期颗粒物浓度高于非采暖期;室外颗粒物浓度高于室内。对室内、外TSP贡献最大的是粒径2.5～7.0μm的颗粒物(PM>2.5～7.0),相应的构成比分别为37.58%和34.70%,其中室内污染以PM≤7.0(粒径≤7.0μm的颗粒物)为主,室外污染以PM>2.5(粒径>2.5μm的颗粒物)为主。不同粒径颗粒物相关性分析结果表明,TSP与PM>2.5～7.0相关性最强,相关系数为0.928 0。室内、外采暖期PM>2.5～7.0相关性最强,采暖期相关系数高达0.675 3。结论太原市主要颗粒物污染为PM>2.5～7.0,室外空气颗粒物污染对室内影响较大,采暖期室内、外PM>2.5～7.0高度相关。     

采暖期大气中不同粒径颗粒物污染及其重金属分布状况

目的了解采暖期不同粒径大气颗粒物污染状况及其重金属分布状态。方法于2003年12月-2004年1月在天津市某市中心区利用大气自动采样仪全天采集大气中颗粒物样品,连续采样32d。用原子吸收光谱法、原子荧光光谱法和等离子发射光谱法,定性检测颗粒物中载带的重金属,并对其中9种重金属进行定量测定。结果在采暖期内TSP、IP、PM25的日均值超标率分别为54．55％,57．58％,84．85％。颗粒中载带的部分重金属含量较高,如Cd、Pb和Ni都达到100mg／m^3以上。结论采暖期大气颗粒物污染严重;PM25细颗粒物对重金属的载带能力较TSP和IP更强,对人体健康的危害更大。     

西安市大气颗粒物污染现状及其金属特征研究

目的了解西安市大气颗粒物及其金属特征。方法于2001年采暖期和非采暖期在西安市工业区、混合区、交通繁忙区和对照区采集大气总悬浮颗粒物(TSP)样品96份。测定大气TSP浓度及TSP无机提取物中铅(Pb)、锰(Mn)、铬(Cr)、镍(Ni)、镉(Cd)等重金属含量。结果西安市采暖期大气TSP浓度(0.5865mg/m3)显著高于非采暖期(0.3535mg/m3),P<0.05。采暖期和非采暖期工业区、混合区、交通繁忙区大气TSP浓度均显著高于相应对照区(P<0.05)。采暖期和非采暖期工业区、混合区、交通繁忙区TSP无机提取物中Pb、Mn含量均高于相应对照区(P<0.05)。采暖期工业区、混合区、交通繁忙区TSP无机提取物中Pb、Cr、Cd含量均高于相应非采暖期(P<0.05)。结论西安市大气TSP污染与燃煤采暖有关。燃煤采暖也可能是大气中某些重金属含量较高的主要原因之一。     

沙尘天气期间大气PM2.5和PM10中部分元素浓度的变化特征

目的探讨沙尘天气期间大气颗粒物PM2.5和PM10质量浓度的变化及其部分元素浓度的变化特征。方法于2008年4月26日—6月11日,对北京和内蒙古阿拉善盟两地沙尘天气和非沙尘天气期间大气颗粒物进行采样,以重量法计算PM2.5和PM10的日均质量浓度,并用原子吸收光谱法、X荧光分析法对其部分元素浓度进行测定。采用Wilcoxon秩和检验比较沙尘天气和非沙尘天气PM2.5和PM10的质量浓度,采用富集因子分析颗粒物中金属组分的分布特征。结果沙尘天气发生时阿拉善盟大气PM2.5和PM10质量浓度出现相应的峰值,其远高于非沙尘天气PM2.5和PM10的平均值(P0.05);北京大气PM10质量浓度在沙尘天气高于非沙尘天气(P0.05),而PM2.5的质量浓度变化差异无统计学意义。且北京和阿拉善盟在沙尘天气和非沙尘天气颗粒物质量浓度的变化趋势相似。阿拉善盟大气PM10中常量元素(K、Ca、Na、Mg)和污染元素(Pb、Cr、Cd、As)的浓度在沙尘天气升高(P0.05),PM2.5中各元素浓度在沙尘天气升高,但差异无统计学意义。与非沙尘天气比较,沙尘天气北京大气PM10中Cd浓度升高,差异有统计学意义(P0.05);其他7种元素浓度升高,差异无统计学意义。北京大气PM2.5中Pb、As、Cd、K、Na元素浓度在沙尘天气降低,差异无统计学意义;PM2.5中Cr、Ca、Mg元素浓度在沙尘天气升高,差异无统计学意义。富集因子分析法显示,两个采样点富集因子大于1小于10的元素有Na、Mg、Cr,富集因子大于10的元素有Ca、Pb、As。结论沙尘天气时大气PM2.5和PM10的浓度显著升高;同时,其中的元素浓度在沙尘天气时也有上升的趋势。研究发现,污染元素Pb、As容易在粒径较小的PM2.5中聚集,并且主要受人为活动的影响,可能与沙尘天气无关联。     

Concentrations of nano and related ambient air pollutants at a traffic sampling site

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5 -10), fine (PM2.5), ultrafine (PM0.056-1) and nano (<0.056 microm) particle concentrations and size distributions at a traffic sampling site in winter in central Taiwan, from November 2004 to January 2005. Concentrations of metallic elements (Fe, Mg, Cr, Zn, Pb, Cu) and major ion (SO4(2-), NO3(-), NH4(+)) in particles of various sizes (nano, ultrafine, fine and coarse) were measured. Ambient air particulates generally exhibited a bimodal size distribution in the range 0.056-10 microm. The results show that the concentrations followed the order, Fe>Mg>Cr>Zn>Pb> Cu in PM10, fine, ultrafine and nano-sized particles. Moreover, the data showed that the average metallic elements Fe and Zn have similar concentration distributions: the concentration decreased as the particle size fell in the nano size range.     

Rapid determination of toxic and rare-earth elements in teas by particle nebulization-ICPMS

Toxic elements profiling of teas is vital in terms of both quality control as well as a means to generate a comprehensive database for human-health-risk assessment. Accordingly, in the present study, a rapid method using direct nebulization of tea particles for inductively coupled plasma (ICP) ionization and subsequent detection of toxic elements by mass spectrometry (MS) was developed. Dried and well grounded tea particles were stably dispersed in 0.5% polyethylene-imine and the particle slurries were analyzed by ICP-MS using aqueous standard calibration. Monitoring the nebulization, transportation, and ionization behaviors of particles of different sizes revealed that particles with a mean size of 1 μm provide values comparable with those of aqueous standards containing equivalent concentrations of the analyte. The excellent recoveries of the method (90–105%) were verified by analyzing two tea certified reference materials, and the detection limits ranged from 0.03 (for Tm) to 1.2 (for Cr) μg kg⁻¹. Then, we performed screening analysis of five toxic elements (As, Cd, Cr, Hg, and Pb) and 16 rare-earth elements in 20 Pu’er teas, and the results revealed that the contents of all the toxic elements and heavy rare earth oxides were low level, where those of the light rare-earth oxides were high. Furthermore, the total rare-earth oxides content of 30% of the Pu’er teas exceeded the Chinese National limit.     

采暖期大气超细颗粒物污染浓度特征研究

目的调查我国大气污染典型地区采暖期超细颗粒物(UFPs)的污染特征,为今后开展UFPs的健康效应研究提供实验依据。方法于2017年1月2-15日在天津市中心某交通路口采用WPS-1000XP型宽范围颗粒粒度仪监测UFPs的粒数浓度、表面积浓度和质量浓度;使用DUSTMATE型手持式环境粉尘检测仪同步监测PM_(2.5)和PM_1的质量浓度。结果监测点采暖期PM_(0.5)和UFPs粒数浓度最高可达33 484粒/cm~3和22 461粒/cm~3,平均水平分别为19 185粒/cm~3和13 184粒/cm~3;UFPs表面积浓度最高可达264.2μm~2/cm~3,平均水平为126.69μm~2/cm~3;UFPs质量浓度最高观测到3.2μg/m~3,平均水平为1.6μg/m~3;PM_(2.5)和PM_1最高质量浓度分别可达600.0μg/m~3和201.6μg/m~3,平均水平分别为96.94μg/m~3和45.33μg/m~3;相关性分析显示,在8:30这一时刻UFPs粒数浓度与PM_(2.5)质量浓度呈负相关。结论监测点采暖期UFPs污染水平较高,有必要针对UFPs开展长期监测及健康危害研究。     

Characterization of wood dust from furniture by scanning electron microscopy and energy-dispersive x-ray analysis

Study characterized and analyzed form factor, elementary composition and particle size of wood dust, in order to understand its harmful health effects on carpenters in Quindío (Colombia). Once particle characteristics (size distributions, aerodynamic equivalent diameter (D(α)), elemental composition and shape factors) were analyzed, particles were then characterized via scanning electron microscopy (SEM) in conjunction with energy dispersive X-ray analysis (EDXRA). SEM analysis of particulate matter showed: 1) cone-shaped particle ranged from 2.09 to 48.79 μm D(α); 2) rectangular prism-shaped particle from 2.47 to 72.9 μm D(α); 3) cylindrically-shaped particle from 2.5 to 48.79 μm D(α); and 4) spherically-shaped particle from 2.61 to 51.93 μm D(α). EDXRA reveals presence of chemical elements from paints and varnishes such as Ca, K, Na and Cr. SEM/EDXRA contributes in a significant manner to the morphological characterization of wood dust. It is obvious that the type of particles sampled is a complex function of shapes and sizes of particles. Thus, it is important to investigate the influence of particles characteristics, morphology, shapes and D(α) that may affect the health of carpenters in Quindío.     

儿科用静脉营养液中加入蔗糖铁对脂肪乳剂稳定性的影响

目的评估静脉营养液（TNA）中加入蔗糖铁对脂肪乳剂稳定性的影响。方法根据静脉营养配制操作规范在100mlTNA中分别加入0、0．25、0．50、0．75、1．00mg铁剂,每组各10袋。在0、24、48、72h时,采用扫描电镜观察各组脂肪颗粒直径,计算出直径〉0．5μm颗粒的百分比;并测定各组TNA的pH值及渗透浓度。结果不同时间点各组TNA的脂肪颗粒直径、直径〉0．5μm的颗粒百分比、pH值及渗透浓度差异均无统计学性意义（P均〉0．05）。在72h内,各组脂肪颗粒平均直径均〈0．5μm,各组均未见到直径〉5μm的脂肪颗粒。结论含蔗糖铁浓度0．25—1．00mg／100ml的TNA是稳定的。     

大气细菌粒子浓度的时间分布特征及最佳采样时间的研究

用ＭＦ－４５型和ＨＴＫ－２０１型空气微生物采样器分别在北京、天津和沈阳三地观测了不同季节和一天中大气细菌粒子的浓度及其变化。结果表明：京、津二地春季大气细菌粒子浓度高，分别为２０５３个／ｍ３和２５５６个／ｍ３；夏季低，分别为９９５个／ｍ３和１０６４个／ｍ３。沈阳秋季大气细菌粒子浓度高，为１０１０８个／ｍ３；冬季低，为１２９４个／ｍ３。一天中，大气细菌粒子浓度呈双峰型变化，６：００～７：００和１８：００时大气细菌粒子浓度高，１１：００～１３：００和１：００～２：００时大气细菌粒子浓度低。根据大气细菌粒子浓度的季节变化和一天中大气细菌粒子浓度的时间分布特征，经过京、津、沈三地一天中分别１２次、８次、６次和４次不同采样时间组合的大气细菌粒子浓度的数理统计分析，大气细菌粒子浓度的监测拟集中在一年冬、春、夏、秋四季的中间月份，即１月、４月、７月、１０月进行；一天中采样８次的时间序列可为７：００、１０：００、１３：００、１６：００、１９：００、２２：００、１：００、４：００一天采样４次的时间序列可为５：００、１１：００、１７：００、２３：００。白天采样４次的时间序列可为春、秋季６：００、９：００、１２：００、１５：００?     

The effect of particle size and different extractants on the contents of heavy metals in roadside dusts

The roadside dusts collected from three selected sites with marked differences in annual average daily traffic (AADT) values were divided into size classes according to particle size. The total, extractable, and water-soluble metal contents were determined using mixed acid, 1 m NH₄OAc (pH 7.0), and distilled water as extractants. It was found that dust particles with a size smaller than 125 μm belonged to a homogeneous group and did not have a significant difference in metal contents. In using dust as a parameter to indicate the level of Pb contamination, a particle size of 125 μm and the extractable metal contents, using NH₄OAc, should be used.     

Characterization of fine particles from machining in automotive plants

Sampling of the full range of particle sizes was carried out on 16 processes in six different General Motors plants over a period of 2.5 years. This article deals with particle characterization from five of the processes that relate to machining, specifically, wet machining with water-based fluids from old and new technology processes, grinding with straight oils from old and new technology processes, and dry machining. The concentrations measured by different instruments were in reasonable agreement, although the light-scattering instrument generally produced higher values than filters. Of the processes studied, the old technology grinding using straight oils generated the highest particle concentrations. The new technology controls (enclosed, vented machines) were highly effective but more so for large particles than small particles. The particle size distribution was shifted to smaller particles with enclosed processes. Dry machining generated the largest particles of all processes studied.     

Exposure characterization of metal oxide nanoparticles in the workplace

This study presents exposure data for various metal oxides in facilities that produce or use nanoscale metal oxides. Exposure assessment surveys were conducted at seven facilities encompassing small, medium, and large manufacturers and end users of nanoscale (particles <0.1 μm diameter) metal oxides, including the oxides of titanium, magnesium, yttrium, aluminum, calcium, and iron. Half- and full-shift sampling consisting of various direct-reading and mass-based area and personal aerosol sampling was employed to measure exposure for various tasks. Workers in large facilities performing handling tasks had the highest mass concentrations for all analytes. However, higher mass concentrations occurred in medium facilities and during production for all analytes in area samples. Medium-sized facilities had higher particle number concentrations in the air, followed by small facilities for all particle sizes measured. Production processes generally had the highest particle number concentrations, particularly for the smaller particles. Similar to particle number, the medium-sized facilities and production process had the highest particle surface area concentration. TEM analysis confirmed the presence of the specific metal oxides particles of interest, and the majority of the particles were agglomerated, with the predominant particle size being between 0.1 and 1 μm. The greatest potential for exposure to workers occurred during the handling process. However, the exposure is occurring at levels that are well below established and proposed limits.     

北京市大气PM_(2.5)中17种元素的污染特征研究

目的了解北京市大气PM_(2.5)中17种元素的浓度水平及季节变化。方法在北京市于2014年3月至2015年2月每月连续7 d使用中流量大气颗粒物采样器和石英滤膜采集大气PM_(2.5),同时记录大气的温度、相对湿度和风速等气象因素。采用微波消解-ICP/MS测定采集的颗粒物中17种元素的浓度。分析17种元素浓度与气象因素之间的相关性以及霾日和非霾日不同元素的浓度差别。结果北京市大气PM_(2.5)中Fe、Cu、Zn和Pb的质量浓度占所检测元素总浓度的92.69%,大气中元素成分与日均温度、日均风速呈现负相关关系,与日均相对湿度正相关。霾日大气PM_(2.5)中17种元素的浓度高于非霾日。结论北京市大气PM_(2.5)中元素的浓度与温度、风速等气象因素有关,且有着明显的季节变化。霾日大气PM_(2.5)种元素的污染严重。