长春市大气颗粒物PM_(10)分布及其与气象因子的相关分析

利用2007年3月—2008年2月期间大气颗粒物PM10浓度值资料研究PM10分布及其与气象因子关系,旨在明确长春市PM10污染现状,便于相关部门加以控制。结果表明:1/10左右天数的长春市PM10浓度超过国家二级标准,基本均在冬季采暖期;一天之中PM10浓度呈双峰双谷型变化;一年4个季节中风速与PM10浓度相关性最显著,其次是温度和能见度;降水量只在夏季与PM10浓度相关性较好。     

通道县城区PM_(10)、PM_(2.5)质量浓度变化和特征分析

该文应用了2016～2019年通道县空气自动站的监测数据,研究了通道县大气环境中PM_(10)和PM_(2.5)质量浓度分布特征及污染现状,结果表明:环境空气中PM_(10)与PM_(2.5)质量浓度有明显的年变化、季变化、月变化特征,PM_(10)的年均质量浓度38.0 ug/m~3～81.0 ug/m~3,平均值53.75 ug/m~3;PM_(2.5)的年均值质量浓度范围在23.0 ug/m~3～49.0 ug/m~3,平均33.25 ug/m~3;二者年均值浓度均以2016年居高,超标率最高在2017年;季均质量浓度以冬季污染最重,夏季污染较轻;24 h连续监测时段呈现有周期性的波动规律,特护期峰值一般出现在中午13﹕00～14:00或夜间23:00左右,非特护期PM_(10)和PM_(2.5)在11.00左右出现高端值;月浓度最高值出现在春冬季节的3月、1月和2月,最低值出现在夏季的7月;PM_(2.5)/PM_(10)比值为40.2%～70.2%,平均61.8%,PM_(2.5)和PM_(10)质量浓度变化基本一致,与城市人群活动、本地污染积累、境外输入污染渗透、气象因素等密切相关。     

陕西省榆林市冬季PM_(10)和PM_(2.5)的污染特征

为了探讨陕西省榆林市冬季大气颗粒物的污染特征,2013年11月对榆林市3个采样点进行可吸入颗粒物(PM10)和细颗粒物(PM2.5)同步观测,利用离子色谱法和热光分析法测定PM10和PM2.5中无机水溶性离子和碳组分的浓度。结果表明:3个采样点PM10和PM2.5日均质量浓度分别为162、74μg/m3,颗粒物浓度由大到小的采样点为环保旧站、实验中学和环保大厦;PM10中有机碳和元素碳的质量浓度空间分布与颗粒物的相同;PM2.5中有碳组分在环保旧站和实验中学的浓度接近,都大于环保大厦的;无机离子中SO42-和Ca2+浓度最大;PM10与PM2.5整体偏碱性,亏损的阴离子主要是CO32-;扬尘在PM10中的比例远远大于其他组分;PM2.5中碳组分含量较大,其次是土壤尘、硫酸盐、氯化物和硝酸盐等;治理PM10和PM2.5污染应以加强扬尘控制和减少燃煤污染物排放为主。     

西安市夜间土方工程施工扬尘排放特征分析

为探究土方工程施工扬尘排放特征,基于土方作业现场采集与检测所得扬尘浓度数值和扬尘颗粒物粒径值以及工地气象因子参数,对施工现场扬尘浓度变化趋势、气象因子对扬尘排放的影响以及土方施工扬尘的粒径分布特征予以解析。结果表明,测试期间TSP浓度和PM10浓度值变化较大,并出现短时间浓度峰值,施工现场土方施工扬尘既受具体施工活动的影响又与气象因子有关。施工现场土方施工作业时PM2.5、PM10和TSP浓度与温度和湿度呈正相关,与风速和风向呈负相关。土方施工时粒径较大的颗粒物所占比例高于施工现场大气和背景值,粒径不小于10μm的颗粒物占比61.24%,土方施工扬尘是西安市环境大气PM10和TSP的来源之一,工地内运输车辆及土方施工活动均为重要扬尘源。土方作业时PM2.5:PM10:TSP=0.01:0.55:1,夜间土方工程施工扬尘对西安市环境大气PM2.5的贡献能力有限。     

北京城区和远郊区大气细颗粒PM_(2.5)元素特征对比分析

为了对比大气悬浮颗粒PM2.5及其所含元素在北京城区与远郊区的特征,在2007年不同季节和2008年北京奥运会期间进行了PM2.5的采样分析。结果表明:城区PM2.5和元素的浓度均高于郊区,元素浓度在城区与郊区具有不同的季节变化特征,春、冬季地壳元素浓度在城区与郊区都有所增加,在城区S元素和其它污染元素在秋、冬季最高,而郊区S元素浓度在夏季最高。污染元素的富集程度夏秋季高于春冬季,郊区高于城区,城、郊两地PM2.5中元素来源相似。雾霾天PM2.5及元素浓度在城区增加明显,奥运期间污染元素的质量分数较奥运前明显降低。     

沙尘期间大气颗粒PM_(10)与PM_(2.5)化学组分的浓度变化及来源研究

于2006年3月—4月北京沙尘发生期间,监测了沙尘与非沙尘期间悬浮颗粒PM10和PM2.5质量浓度,分析了样品中无机水溶性离子和金属元素。结果显示:沙尘天气导致PM10和PM2.5质量浓度上升,粗颗粒物质量浓度明显上升,细颗粒物受到的影响相对较小。SO42-、NO3-和NH4+为PM10与PM2.5主要水溶性离子。沙尘与非沙尘期间SO42-、NO3-和NH4+浓度变化表现出不稳定性,可能与沙尘的强度和持续时间、来源有关,沙尘下来自于土壤源Ca2+和Mg2+浓度都显然提高。沙尘期间Sc、Ti、V、Cr、Mn、Co、Ni、Rb和Cs金属元素浓度高于非沙尘期间浓度,并且富集因子系数都小于10,说明主要来自于自然源,而Zn、Se、Cd、Pb和Bi这5种元素浓度随沙尘的侵入并没增加其含量,反而使浓度有所下降,富集因子和富集程度对比表明这些元素主要来自于当地污染源。     

西安市春季大气颗粒物PM_(2.5)与PM_(10)的特征

2010年4月在西安市区4个点使用低流量采样器同步连续采集2周(24 h/d)细颗粒物PM2.5和可吸入颗粒物PM10样品,分别利用热光碳分析仪、离子色谱和X射线荧光光谱仪分析其含碳组分(有机碳和元素碳)、水溶性无机离子(NH4+、Na+、K+、Ca2+、Mg2+、F-、Cl-、SO42-、NO3-)和元素Ca、Fe等浓度。结果表明,沙尘暴期间,PM10的质量浓度是PM2.5的3倍,PM2.5和PM10中有机碳浓度大于正常天气的,SO42--NO3--NH4+浓度急剧减小,明显小于正常天气,这与干燥沙尘暴的稀释作用有关;后向轨迹、气溶胶指数和Ca与Fe元素质量浓度比验证了沙尘暴颗粒来源西部戈壁沙尘和黄土高原;阴阳离子平衡计算显示沙尘事件颗粒物呈碱性,阴阳离子差异估算的CO32-含量与Ca2+具有强相关性,表明沙尘暴颗粒以CaCO3为主。     

杭州主城区悬浮细颗粒PM_(2.5)浓度变化及其组分分析

利用杭州市区2006—2008年大气悬浮颗粒PM2.5和PM2.5-10的监测资料,研究它们的物化特征。结果表明:杭州主城区PM2.5和PM2.5-103年的平均浓度分别为0.073、0.037mg·m-3,ρ(PM2.5)/ρ(PM2.5-10)的比值为1.86。PM2.5浓度存在双峰型日变化,以9:00和18:00为峰值,日变化幅度较大,并呈现冬高、夏低的季节变化。PM2.5化学组分分析表明:PM2.5中含量最多的是有机碳,占24.4%,其次是SO42-,不同组分呈现不同的季节变化。     

南京市东郊大气颗粒物污染特征

为了研究南京东郊大气颗粒物污染特征,利用安德森8级粒度分布采样器采样,并结合大气监测数据,综合分析2013—2014年间南京东郊大气颗粒物的粒度分布特征和大气污染物的污染水平及其相互关系。结果表明:南京市大气污染主要由粒径为0.43~2.10μm的大气颗粒物引起,其中12月份污染最严重,且首要污染物为细颗粒物PM2.5;温度、降雨量、风速等气象因素对颗粒物呈负相关性影响;灰霾天时颗粒物浓度受SO2、NO2的正相关性影响比非灰霾天时大,且NO2浓度对颗粒物浓度的影响比SO2浓度的影响大。     

保定市区2013年环境空气质量状况及污染原因分析

对保定市6个环境监测国控点2013年的SO2、NO2、PM10、PM2.5监测数据,按时间段进行了统计分析,结果表明:4种空气污染物季节性污染特征明显,月均浓度在采暖期比非采暖期有显著增加;由于受到燃煤及不利气象条件影响,SO2、NO2月浓度变化曲线呈现冬季高、夏季低的"U"字型分布,采暖期SO2浓度约为非采暖期的3倍。PM10、PM2.5浓度全年波动比较频繁,较大浓度值出现在冬季采暖期。沙尘、扬尘天气和秸秆焚烧对春秋季PM10、PM2.5浓度有贡献。     

Estimation of selected heavy metals and arsenic in PM10 aerosols in the ambient air of the Greater Athens Area, Greece

Aerosol samples of PM(10) were collected during summer and winter 2003 at two different sites in the Messogia Basin northeast of Athens, to demonstrate the variations of heavy metals in PM(10) and examine their relationship with both gaseous pollutants and meteorological parameters. Estimated heavy metals during the experimental campaign were mercury (Hg), cadmium (Cd), lead (Pb), nickel (Ni) and arsenic (As). The average heavy metal concentrations for the first site (Spata) constituted 0.66-14.7ng/m(3) for the summer period and 0.14-19.5ng/m(3) for the winter period. At the second site (Koropi), the corresponding values varied between 0.89 and 13.3ng/m(3) and 0.16 and 24.7ng/m(3), respectively. PM(10) Hg, PM(10) Cd and PM(10) Ni contents showed regular daily variations, with higher mass percentages during the summer, indicating differences in local PM(10) sources for each season. On the contrary, PM(10) Pb presented higher mass percentages during the winter. Examination of the relationship between heavy metals and meteorological parameters indicated a higher correlation with temperature and relative humidity, especially for Pb. In addition, most of the heavy metals (apart from Hg) presented an expected correlation with nitrate oxides (NO(x)), PM(10) and ozone (O(3)). Higher correlations with both meteorological parameters and gaseous pollutants were observed during the winter experimental campaign. Maximum heavy metal concentrations at both sites were observed during days with NE or NNE prevailing winds during the summer campaign, while the winter period was characterized with maximums during days with W or WNW prevailing winds.     

Source apportionment of PM2.5 in Beijing in 2004

Based on measurements of fine particulate matter (PM2.5, i.e., particles with an aerodynamic diameter of 2.5 microm or less) in January and August 2004, serious air pollution persists in Beijing. The chemical analysis included organic and elemental carbon, water-soluble ions, and elemental compositions. The positive matrix factorization (PMF) method was used to apportion the PM2.5 sources. The sources contributing dominantly to PM2.5 mass concentrations are coal combustion in winter and the secondary products in summer. Furthermore, the contributions from motor vehicles, road dusts and biomass burning could not be neglected. The products of biomass burning for winter heating in the area around Beijing could enter the urban area during quasi-quiescent weather conditions. In conclusion, some effective control measures were proposed to reduce the PM2.5 pollution in Beijing.     

A wintertime study of polycyclic aromatic hydrocarbons in PM(2.5) and PM(2.5-10) in Beijing: assessment of energy structure conversion

Sixteen priority polycyclic aromatic (PAHs) in PM(2.5) and PM(2.5-10) samples collected from 20 sites in Beijing, China in December 2005 and January 2006 were analyzed to determine the composition, spatial distribution and sources. Total PAHs of PM(2.5) and PM(2.5-10) ranged from 5.2 to 1062.2 ng m(-3) and 7.6 to 759.7 ng m(-3), respectively, categorized as heavier pollution. Among five kind of functional zones involved, industrial center, commercial area and village were heavily polluted. The mean concentration of PAHs in PM(2.5) of 407 ng m(-3) was 1.67-fold of that in PM(2.5-10), which was relatively high compared to the previous studies (winter in 2001 and 2002). The most evident change was the increase of Flu, BbkF and InP, which are believed to be less harmful and related to the increasing use of clean energy. However, pollution distribution was spatially heterogeneous inside the city. The most polluted sites located in the southeast of the city. Unlike previous studies, fluoranthene was the most abundant component quantified, which could be associated with increasing use of natural gas as clean energy. Compositional analysis and principal component analysis (PCA) suggested that different kinds of combustion were the main source of the PAHs in PM, though contribution of coal was still evident.     

西安黑碳气溶胶的污染特征及其成因分析

对2006年3月～2007年2月在西安获得的黑碳气溶胶观测资料及相关气象资料进行分析。结果表明,西安黑碳气溶胶浓度变化幅度很大,全年黑碳日均浓度变化范围为1400～30000ng·m-3,平均值为10000ng·m-3。在春、秋、冬3季其浓度日变化具有明显的双峰特征。西安市黑碳浓度秋、冬季节的月份高,春、夏月份低。黑碳季节平均浓度分别为春季9400ng·m-3,夏季为7100ng·m-3,秋季12000ng·m-3,冬季11900ng·m-3。黑碳浓度的频次分布表明低浓度值在春季和夏季所占比例大大高于秋、冬季节。研究发现气象要素(风速和混合层高度)对黑碳浓度有重要的影响。     

北京冬季PM_(10)中有机碳与元素碳的高分辨率观测及来源分析

运用先进的RP5400碳颗粒物连续分析仪和TEOM1400a气溶胶质量测量仪于2004年冬季对北京大气PM10及碳气溶胶进行了连续观测,得到了PM10、有机碳(OC)、无机碳(EC)和总碳(TC)的日变化特征。观测期间OC、EC、TC、PM10的浓度和OC/EC比值分别为(21.2±16.0)、(8.9±5.1)、(30.2±20.4)、(172.6±98.3)μg.m-3和2.3±0.9。OC,EC和总碳(TC=OC+EC)分别占PM10质量的(12.4±6.4)%、(5.6±2.3)%和(18±9.2)%。OC,EC和PM10浓度变化范围较大,变化趋势相似,明显受风速影响,风速较大时浓度较小。PM10和OC浓度在夜间明显高于白天,但是EC浓度白天和夜间差别不大。EC在早上交通高峰期间达到最高值,显示了机动车排放源的明显贡献。OC/EC比值在夜间(2.4～2.7)明显高于白天(1.9～2.0),这主要是由于机动车白天排放较多,而夜间机动车相对较少以及燃煤排放较多。北京观测到的TC浓度和OC/EC比值均高于美国、日本的同期观测结果。分析表明北京冬季PM10中有机碳和无机碳以一次性排放为主。应用比值法估算出北京冬季PM10中碳气溶胶的来源主要是机动车(75%贡献)和燃煤(25%)。由此可见,北京PM10中碳污染较为严重,且机动车排放占了较大贡献,需要引起重视。     

Spatial distribution of particulate matter (PM10 and PM2.5) in Seoul Metropolitan Subway stations

The aims of this study are to examine the concentrations of PM10 and PM2.5 in areas within the Seoul Metropolitan Subway network and to provide fundamental data in order to protect respiratory health of subway workers and passengers from air pollutants. A total of 22 subway stations located on lines 1-4 were selected based on subway official's guidance. At these stations both subway worker areas (station offices, rest areas, ticket offices and driver compartments) and passengers areas (station precincts, subway carriages and platforms) were the sites used for measuring the levels of PM. The mean concentrations of PM10 and PM2.5 were relatively higher on platforms, inside subway carriages and in driver compartments than in the other areas monitored. The levels of PM10 and PM2.5 for station precincts and platforms exceeded the 24-h acceptable threshold limits of 150 microg/m3 for PM10 and 35 microg/m3 for PM2.5, which are regulated by the U.S. Environmental Protection Agency (EPA). However, levels measured in station and ticket offices fell below the respective threshold. The mean PM10 and PM2.5 concentrations on platforms located underground were significantly higher than those at ground level (p<0.05).     

Assessment of carcinogenic risk due to inhalation of polycyclic aromatic hydrocarbons in PM10 from an industrial city: a Korean case-study

This study investigated the effects of meteorological conditions and spatial variations on the toxicity of polycyclic aromatic hydrocarbons (PAHs) in airborne PM(10) in Ulsan, the largest industrial city in Korea. Daily PM(10) samples were collected on quartz microfiber filters using high volume samplers located in a downtown area, a residential area and an industrial area of Ulsan during spring and summer sampling periods. Sixteen individual PAHs were extracted into a mixture solution of dichloromethane and n-hexane (1:1, v/v) in an ultrasonic bath and were analyzed using a high performance liquid chromatography system with an ultra-violet detector (HPLC-UVD). The average total PAH concentrations from the three representative sampling sites of Ulsan ranged from 16.15 to 57.12 ng/m(3) in spring and from 11.11 to 34.56 ng/m(3) in summer. The toxicity equivalent concentrations (TEQs) of the PAHs in PM(10) of Ulsan ranged from 1.82 to 13.1 ng/m(3), with an average level of 4.17 ng/m(3). The highest TEQs were found in the downtown area, which had an average value of 6.30 ng/m(3) in spring and 5.52 ng/m(3) in summer. BaP and DahA were identified as the major carcinogenic PAHs that contributed to 34.8 and 59.4% of the total carcinogenic potency of PAHs in PM(10) in Ulsan. The identified TEQs were highly correlated (r(2) = 0.73-0.90, p<0.01) with the total PAH concentrations for each area. The TEQs showed a significant correlation (p < 0.01) with the concentration of air pollutants, including PM(10), PM(2.5) and NO(2).