常州市大气PM_(2.5)中水溶性离子组成及来源

于2013年3月~2014年4月采集常州市郊区、工业区、居民区和背景点的春季、秋季大气PM_(2.5)样品,用离子色谱法分析其中水溶性离子成分,对其组成、分布特征及来源等进行研究。结果表明:SO_4~(2–)、NO_3~–和NH_4~+是常州市PM_(2.5)中的主要水溶性离子,3种离子在PM_(2.5)中占比为18%~33%。不同功能区之间水溶性离子的占比和差异较小,常州背景点可能受到周边城市污染输送的影响。在PM_(2.5)中,NH_4~+与SO_4~(2–)和NO_3~–主要以(NH_4)_2SO_4和NH_NO_3存在;硫转化率(SOR)和氮转化率(NOR)是衡量二次无机粒子转化的有效手段,常州市各功能区的SOR均大于NOR;春季SOR0.25,NOR0.1,满足发生强烈光化学氧化反应的条件。     

Respiratory hospital admissions in young children living near metal smelters,pulp mills and oil refineries in two Canadian provinces

BackgroundIndustrial plants emit air pollutants like fine particles (PM2.5), sulfur dioxide (SO2) and nitrogen dioxide (NO2) that may affect the health of individuals living nearby.ObjectiveTo assess the effects of community exposure to air emissions of PM2.5, SO2, and NO2 from pulp mills, oil refineries, metal smelters, on respiratory hospital admissions in young children in Quebec (QC) and British Columbia (BC), Canada.MethodsWe assessed QC, BC and pooled associations between the following estimates of exposure and hospital admissions for asthma and bronchiolitis in children aged 2–4 years for the years 2002–2010: i) Crude emission exposures at the residential postal codes of children, calculated by multiplying estimated daily emissions of PM2.5, SO2, or NO2 from all nearby (< 7.5 km) pulp mills, oil refineries, metal smelters emitting yearly ≥ 50 t and their total emissions, by the percent of the day each postal code was downwind; ii) Daily levels of these pollutants at central ambient monitoring stations nearby the industries and the children's residences.ResultsSeventy-one major industries were selected between QC and BC, with a total of 2868 cases included in our analyses. More cases were exposed to emissions from major industries in QC than in BC (e.g. 2505 admissions near SO2 industrial emitters in QC vs 334 in BC), although air pollutant levels were similar. Odds ratios (ORs) for crude refinery and smelter emissions were positive in QC but more variable in BC. For example with PM2.5 in QC, ORs were 1.13 per 0.15 t/day (95% CI: 1.00–1.27) and 1.03 (95% CI: 0.99–1.07) for refinery and smelter emissions, respectively. Pooled results of QC and BC for crude total SO2 emissions from all sources indicated a 1% increase (0–3%) in odds of hospital admissions per 1.50 t/day increase in exposure. Associations with measured pollutant levels were only seen in BC, with SO2 and NO2.ConclusionHospital admissions for wheezing diseases in young children were associated with community exposure to industrial air pollutant emissions. Future work is needed to better assess the risk of exposure to complex mixture of air pollutants from multiple industrial sources.     

南昌市环境空气污染时空变化特征及影响因素研究

选取2014~2017年南昌市不同时间尺度AQI及主要空气污染物数据,利用GIS技术、神经网络分析、后向轨迹模型及地统计分析方法,分析了南昌市环境空气污染时空变化特征及影响因素。结果表明,南昌市近年来空气质量总体变化不大,空气质量等级以良为主,占全年比例为57%~61%。但首要污染物变化较大,即PM2.5比例显著下降,NO2和O3比例显著上升,PM10变化不大。南昌市空气污染季节变化显著,冬春季空气质量较差,以PM10、PM2.5污染为主,夏季空气质量最好,以O3污染为主。空气污染周变化以周末及周一污染较重、周四污染最轻,说明南昌市空气污染除了与群众出行习惯有关,还存在其他影响因素。南昌市空气质量日变化呈双峰型（9:00~11:00和20:00~22:00）,主要受上、下班高峰期带来的交通尾气影响。南昌市空气污染空间变化呈典型的“郊区-市区”分布,其中AQI、PM10、PM2.5、SO2、NO2、CO值均以市区较高、郊区较低,而O3的空间分布规律正好相反,这主要与城区NOx排放较多,O3易与其迅速反应而消耗有关。后向轨迹聚类分析结果表明,来自本地的短轨迹气团占比高,对PM2.5、PM10、NO2、O3的影响大。气象因素上,PM2.5、PM10、NO2受相对湿度影响较大,O3受温度影响较大。     

Using air pollution based community clusters to explore air pollution health effects in children

To study respiratory health effects of long-term exposure to ambient air pollutant mixture, we observed 7058 school children 5-16 years of age living in the four Chinese cities of Lanzhou, Chongqing, Wuhan, and Guangzhou. These children were enrolled from elementary schools located in eight districts, one urban district and one suburban district in each of the above cities. Ambient levels of PM(2.5), PM(10-2.5), total suspended particles (TSP), SO(2), and NO(x) were measured in these districts from 1993 to 1996. Based on a cluster analysis of arithmetic mean concentrations of PM(2.5), PM(10-2.5), (TSP-PM(10)), SO(2), and NO(x), we classified these children into four ordinal categories of exposure to ambient air pollutant mixtures. We tested for exposure-response relationships using logistic regression models, controlling for relevant covariates. We observed monotonic, positive relationships of exposure to the pollutant mixture with prevalence rates of cough with phlegm and wheeze. Other outcomes were not associated with the exposure in a monotonic exposure-response pattern. Even so, odds ratios for cough, phlegm, bronchitis, and asthma in the higher exposure district clusters were all higher than in the lowest exposure district cluster. We found evidence that exposure to the pollutant mixtures had adverse effects on children living in the four Chinese cities.     

Measurements and analysis of criteria pollutants in New Delhi, India

Ambient concentrations of carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and total suspended particulates (TSP) were measured from January 1997 to November 1998 in the center of downtown [the Income Tax Office (ITO) located on B.S.G. Marg] New Delhi, India. The data consist of 24-h averages of SO2, NOx, and TSP as well as 8 and 24-h averages of CO. The measurements were made in an effort to characterize air pollution in the urban environment of New Delhi and assist in the development of an air quality index. The yearly average CO, NOx, SO2, and TSP concentrations for 1997 and 1998 were found to be 4810+/-2287 and 5772+/-2116 microg/m3, 83+/-35 and 64+/-22 microg/m3, 20+/-8 and 23+/-7 microg/m3, and 409+/-110 and 365+/-100 microg/m3, respectively. In general, the maximum CO, SO2, NOx, and TSP values occurred during the winter with minimum values occurring during the summer, which can be attributed to a combination of meteorological conditions and photochemical activity in the region. The ratio of CO/NOx (approximately 50) indicates that mobile sources are the predominant contributors for these two compounds in the urban air pollution problem in New Delhi. The ratio of SO2/NOx (approximately 0.6) indicates that point sources are contributing to SO2 pollution in the city. The averaged background CO concentrations in New Delhi were also calculated (approximately 1939 microg/m3) which exceed those for Eastern USA (approximately 500 microg/m3). Further, all measured concentrations exceeded the US National Ambient Air Quality Standards (NAAQS) except for SO2. TSP was identified as exceeding the standard on the most frequent basis.     

贵阳市主城区空气质量指数时空分布特征

为了解贵阳市主城区空气质量指数的时间分布和空间分布特征，采用时间序列法和插值法统计分析了2013~2015年贵阳市9个空气自动监测点SO2、NO2、PM10、PM25、CO的监测数据。结果表明：2013~2015年期间，贵阳市主城区空气质量整体良好,优于Ⅱ级空气质量标准，IAQISO2、IAQINO2、IAQIPM10、IAQIPM25、IAQICO的年均值呈现降低趋势, 空气污染物得到一定的控制；季节变化和月变化分析表现出冬季空气质量最差，夏季最好的特征。春节半月ISO2、IAQINO2、IAQIPM10、IAQIPM25的均值好于冬季均值，反映了工业和交通污染源的主控作用。空间分布上，IAQISO2、IAQINO2、IAQIPM10、IAQIPM25、IAQICO呈现“市区高，郊区低”的分布特征，空气质量指数较高的区域集中在贵阳市主城区中部和东北部     

Levels and major sources of PM2.5 and PM10 in Bangkok Metropolitan Region

This research was the first long-term attempt to concurrently measure and identify major sources of both PM(10) and PM(2.5) in Bangkok Metropolitan Region (BMR). Ambient PM(10) and PM(2.5) were evaluated at four monitoring stations and analyzed for elemental compositions, water-soluble ions, and total carbon during February 2002-January 2003. Fifteen chemical elements, four water-soluble ions, and total carbon were analyzed to assist major source identification by a receptor model approach, known as chemical mass balance. PM(10) and PM(2.5) were significantly different (p<0.05) at all sites and 24 h averages were high at traffic location while two separated residential sites were similar. Seasonal difference of PM(10) and PM(2.5) concentrations was distinct between dry and wet seasons. Major source of PM(10) at the traffic site indicated that automobile emissions and biomass burning-related sources contributed approximately 33% each. Automobiles contributed approximately 39 and 22% of PM(10) mass at two residential sites while biomass burning contributed about 36 and 28%. PM(10) from re-suspended soil and cooking sources accounted for 10 to 15% at a residential site. Major sources of PM(2.5) at traffic site were automobile and biomass burning, contributing approximately 32 and 26%, respectively. Biomass burning was the major source of PM(2.5) mass concentrations at residential sites. Meat cooking also accounted for 31% of PM(2.5) mass at a low impact site. Automobile, biomass burning, and road dust were less significant, contributed 10, 6, and 5%, respectively. Major sources identification at some location had difficulty to achieve performance criteria due to limited source profiles. Improved in characterize other sources profiles will help local authority to better air quality.     

Differentiating the effects of fine and coarse particles on daily mortality in Shanghai, China

The findings on health effects of ambient fine particles (PM2.5) and coarse particles (PM10-2.5) remain inconsistent. In China, PM2.5 and PM10-2.5 are not the criteria air pollutants, and their monitoring data are scarce. There have been no epidemiological studies of health effects of PM2.5 and PM10-2.5 simultaneously in China. We conducted a time series study to examine the acute effects of PM2.5 and PM10-2.5 on daily mortality in Shanghai, China from Mar. 4, 2004 to Dec. 31, 2005. We used the generalized additive model (GAM) with penalized splines to analyze the mortality, air pollution and covariate data. The average concentrations of PM2.5 and PM10-2.5 were 56.4 microg/m3 and 52.3 microg/m3 in our study period, and PM2.5 constituted around 53.0% of the PM10 mass. Compared with the Global Air Quality Guidelines set by World Health Organization (10 microg/m3 for annual mean) and U.S. National Ambient Air Quality Standards (15 microg/m3 for annual mean), the PM2.5 level in Shanghai was much higher. We found that PM2.5 was associated with the death rates from all causes and from cardiorespiratory diseases in Shanghai. We did not find a significant effect of PM10-2.5 on mortality outcomes. A10 microg/m3 increase in the 2-day moving average (lag01) concentration of PM2.5 corresponded to 0.36% (95% CI 0.11%, 0.61%), 0.41% (95% CI 0.01%, 0.82%) and 0.95% (95% CI 0.16%, 1.73%) increase of total, cardiovascular and respiratory mortality. For PM10-2.5, the effects were attenuated and less precise. Our analyses provide the first statistically significant evidence in China that PM2.5 has an adverse effect on population health and strengthen the rationale for further limiting levels of PM2.5 in outdoor air in Shanghai.     

Air pollution and the demand for hospital services: a review

Time-series studies published since 1993 on the association between short-term changes in air quality and use of hospital services, including both inpatient and emergency room use, are reviewed. The use of nonparametric analysis, often incorporating generalized additive models (GAMs), has increased greatly since the early 1990s. There have also been three major multi-city studies, which together analyzed data from well over 100 cities in Europe and North America. Various air pollutants, especially ozone (O(3)), particulate matter (PM), nitrogen dioxide (NO(2)) and sulfur dioxide (SO(2)), were generally found to be significantly associated with increased use of hospital services. Ozone tends to have stronger effects in the summer during periods of higher concentrations. Several studies revealed synergistic effects between pollutants such as PM and SO(2). Overall, short-term exposure to air pollutants is found to be an important predictor of increased hospital and emergency room use around the world.     

城市化水平、工业化水平对空气质量的影响分析——基于湖北省16城市2005～2017年数据的时空模型

基于湖北省16城市2005~2017年数据,应用空间计量模型研究城市化水平、工业化水平对空气SO2、NO2、PM10含量的影响。结果显示,在城市化水平中,人均GDP对空气中SO2含量有显著负向影响,对NO2有显著正向影响,民用汽车的数量、公路里程对城市空气中SO2、NO2、PM10含量有显著正向影响,工业化水平对空气中SO2、NO2显著负向影响,对PM10含量有显著正向影响,人均绿地面积对空气中SO2的含量有显著负向影响,对NO2、PM10的影响不显著。为此,必须加快产业转型升级,做好产业发展规划;必须强化城市民用汽车尾气排放检测,加强城市配套园林建设;必须建立城市绿色发展联动机制,做好区域巡查监管。     

基于小波分析与Mann-Kendall法的上海市近12年空气质量变化

综合应用小波分析和Mann Kendall非参数检验方法,对上海市近12 a PM10、SO2和NO2逐日空气污染指数序列进行分析,揭示了空气污染变化的多尺度特征、变化趋势和突变特性,以深入了解上海市空气质量状况。结果表明：PM10、SO2和NO2污染序列呈现多尺度的变化特征,具有1 000 d和300 d左右的中、小时间尺度周期。在小尺度上,各序列具有300 d左右的主周期和30 d左右的次周期。空气污染具有“冬重夏轻”的特征,冬季和春季是污染比较严重的时段;2007年夏季以来,空气质量总体趋于好转。近12 a来各序列均呈显著的减少趋势;PM10序列突变开始于2006年7月3日前后,SO2于2010年3月21日前后,NO2则于2006年4月18日前后;突变后,各序列基本均呈显著的下降趋势。最后,提出了未来改善上海市空气质量的相关建议。     

The study of Central Taiwan particles concentration variations during earthquake period

Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over the bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there are more than 20,000 aftershocks following the Taiwan Chi-Chi Earthquake within 3 months. Thus, the mass concentration of particles with aerodynamic diameters smaller than 2.5 microm (PM2.5) and PM2.5-10 was also collected then compared with the total mass concentration of suspended particles (TSP) in this study. The average TSP, PM2.5-10, and PM2.5 concentrations are 106, 24.6, and 58.0 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 69.6 and 127 microg/ m3, respectively. In addition, statistical analysis of the PM10 data from this study and EPA in 1999 yielded a Tstatistic of 0.147, which is smaller than t(0.975,18) = 2.101. It is indicated that there was no significant difference. So, the PM10 concentrations measured after Taiwan Chi-Chi Earthquake in this study were also greater than those data previously obtained from Taiwan EPA in the same region of this area. The relationships between TSP, PM10, PM2.5-10, and PM2.5 particle concentrations and wind speed (R2) are .77, .59, .58, .58, respectively. And the ratios of PM2.5/PM25-10, PM2.5/PM10, and PM10/TSP are 221%, 67.2%, 58.0%, respectively. The average ratios of PM2.5/PM2.5-10 and PM2.5/PM10 increase by about 120% and 17%. It indicated that the fine-particles concentration increases compared to the coarse-particles concentration after 921 Taiwan Chi-Chi Earthquake. And the proposed reasons are that local motor vehicle emissions combined the fine particles transported from the Chi-Chi epicenter. More importantly, the wind direction was mainly blown from southeastern part. These two main factors enhance the fine-particles concentration in this area.     

嘉兴双桥农场大气颗粒物的物理化学特征

为了对长三角地区大气污染进行防治和控制,了解长三角地区大气环境质量变化规律,有必要对其颗粒物的组成及特征进行分析,以揭示其形成机制。采用Partisal plus2025 型连续空气采样机在嘉兴双桥农场（长三角中心）进行采样,利用对采样样品化学分析的结果,分析了PM10、PM25的化学组成、质量浓度的分布特征及其相对关系。 PM25和PM10中19种无机元素质量浓度的总和约占其质量浓度的23%和25%,其中Al、Si、Ca是主要贡献元素;8种水溶性离子质量浓度总和约占PM25和PM10质量浓度的51%和43%,其中NO-3和SO2-4是主要贡献成分;有机碳的质量浓度约占PM25和PM10质量浓度的1612%和1743%,元素碳的质量浓度约占PM25和PM10质量浓度的1697%和1584%,可见该地区存在较严重的二次有机碳污染和元素碳污染。研究结果为揭示大气颗粒物的形成机制和对其污染进行防治和控制提供了基础性的研究数据。     

Particulate matter and black smoke concentration levels in central Athens, Greece

This study presents the statistical analysis of PM(10) and PM(2.5) concentrations (measured at a central site, in the Athens area), along with black smoke (BS) data, for a 2-year period. The biennial average concentrations of PM(10) and PM(2.5) were 75 and 40 microg m(-3). The respective average concentration of BS, as estimated by the OECD method, was 108 microg m(-3). Severe exceedances of the PM(10) air quality standards were recorded. The seasonal variation of PM(10) and BS was less pronounced than the variation of PM(2.5), which concentration was elevated by 14.2% during the cold period. Concentrations of all three pollutants were significantly lower during weekends; however, PM(2.5) and BS displayed a more uniform weekly distribution pattern. PM(10) particles were found to be almost equally comprised by PM(2.5) and PM(10-2.5) particles (PM(2.5)/PM(10) ratio=0.53+/-0.09 microg/m(3)). The average PM(10)/BS value was found lower than unity revealing the inappropriateness of the used reflectance conversion method, for the estimation of mass-equivalent BS concentrations, in the study area, where diesel-powered vehicles mainly control emissions of light-absorbing substances. Important reductions in concentrations were observed during days when drivers of diesel-powered taxies and transportation buses went on strike (reaching 40% for BS). Calm wind conditions were found to have an incremental effect on particle concentrations and were also associated with the appearance of persistent episodic events. Increased PM levels were also observed during southern-southwestern wind flows while significantly lower-than-average concentrations were measured during precipitation events. Separate regression analyses were performed for PM(10), PM(2.5) with BS and NO(x) as independent variables, in an attempt to estimate the relative contribution of specific source types (diesel-powered vehicles) to measured particle levels. The contribution of the diesel-exhaust component to PM(10) mass was estimated at 49.9%, while the corresponding contributions to PM(2.5) mass concentrations was 53.8%. These results may have important implications with the oncoming decision of national authorities to allow the purchase of diesel-powered private cars to the residents of the Greater Athens Area, which was forbidden up to this day.     

Relationship between air pollution and daily mortality in a subtropical city: Taipei, Taiwan

Air pollution has been associated with daily mortality in numerous studies over the past decade. However most of these studies were conducted in the United States and Europe with relatively few done in Asia. In the current study, the association between ambient air pollution and daily mortality in Taipei, Taiwan's largest city which has a subtropical climate was undertaken, for the period 1994-1998 using a case-crossover analysis. This design is an alternative to Poisson time series regression for studying the short-term adverse health effects of air pollution. The air pollutants examined included particulate matter (PM(10)), sulfur dioxide (SO(2)), ozone (O(3)), nitrogen dioxide (NO(2)), and carbon monoxide (CO). The largest observed effect, which was without statistical significance, was seen for NO(2) and CO levels on deaths due to respiratory diseases (ORs=1.013 and 1.014, respectively). The well established link between air pollution levels and daily mortality may not be as strong in cities in subtropical areas, although other factors such as differences in pollutant mix or the underlying health of the population may explain the lack of a strong association in this study. Further studies of this type in cities with varying climates and cultures are needed.     

长沙市两种空气质量预报方法检验对比

为探索新的空气质量预报方法，提高预报准确率，采用统计和对比方法，分析了长沙市空气质量现状，介绍了天气形势相似及动态逐步回归两种空气质量统计预报方法，并对其一年多的运行结果进行了检验和对比。结果表明，长沙市空气污染主要由PM\-\{10\}和SO\-2浓度超标引起, 且具有明显的空间分布特征;5年来长沙城市空气质量明显好转;两种预报方法对各污染物都有一定的预报能力，预报的误差绝对值多集中在30以内，而级别误差基本上在1级以内。两种方法对NO\-2的预报准确率均在98%左右,预报效果优良。绝对误差对比发现，两种预报方法对SO\-2的预报明显优于PM\-\{10\}预报；级别准确率对比时，两种预报方法对3种污染物的预报准确率相近。两种预报方法对3个污染因子的预报准确率呈现出NO\-2优于SO\-2优于PM\-\{10\}的趋势。     

Comparative overview of indoor air quality in Antwerp, Belgium

This comprehensive study, a first in Belgium, aimed at characterizing the residential and school indoor air quality of subgroups that took part in the European Community Respiratory Health Survey and the International Study of Asthma and Allergy in Childhood [Masoli M, Fabian D, Holt S, Beasley R. Global Burden of Asthma, Medical Research Institute of New Zealand, University of Southampton; 2004.] questionnaire-based asthma and related illnesses studies. The principal aim was to perform a base-line study to assess the indoor air quality in Antwerp in terms of various gaseous and particulate pollutants. Secondly, it aimed to establish correlations between these pollutants investigated, the pollutant levels in the indoor and outdoor micro-environments, findings of the previous questionnaire-based studies and an epidemiological study which ran in conjunction with this study. Lastly, these results were compared and evaluated with current indoor and ambient guidelines in various countries This paper presents selected results on PM1, PM2.5 and PM10 mass concentrations and elemental C estimates as black smoke, as well as gaseous NO(2), SO(2), O(3) and BTEX concentrations of 18 residences and 27 schools. These are related to current guidelines of Flanders, Germany, Norway, China and Canada and evaluated with reference to selected similar studies. It was found that indoor sources such as tobacco smoking and carpets, the latter causing re-suspension of dust, are responsible for elevated indoor respirable particulate matter and place school children and residents at risk. Both PM2.5 and PM10 equalled or exceeded the current guidelines adopted by Flanders, noting that 12-h and 24-h PM2.5 were compared with an annual limit value. Indoor and ambient NO(2) concentrations in the school campaign were higher than the annual EU ambient norm. The other studied pollutant levels were below the current guidelines.     

Assessment of ambient air quality in Eskişehir, Turkey

This paper presents an assessment of air quality of the city Eski?ehir, located 230 km southwest to the capital of Turkey. Only five of the major air pollutants, most studied worldwide and available for the region, were considered for the assessment. Available sulphur dioxide (SO(2)), particulate matter (PM), nitrogen dioxide (NO(2)), ozone (O(3)), and non-methane volatile organic carbons (NMVOCs) data from local emission inventory studies provided relative source contributions of the selected pollutants to the region. The contributions of these typical pollution parameters, selected for characterizing such an urban atmosphere, were compared with the data established for other cities in the nation and world countries. Additionally, regional ambient SO(2) and PM concentrations, determined by semi-automatic monitoring at two sites, were gathered from the National Ambient Air Monitoring Network (NAAMN). Regional data for ambient NO(2) (as a precursor of ozone as VOCs) and ozone concentrations, through the application of the passive sampling method, were provided by the still ongoing local air quality monitoring studies conducted at six different sites, as representatives of either the traffic-dense-, or coal/natural gas burning residential-, or industrial/rural-localities of the city. Passively sampled ozone data at a single rural site were also verified with the data from a continuous automatic ozone monitoring system located at that site. Effects of variations in seasonal-activities, newly established railway system, and switching to natural gas usage on the temporal changes of air quality were all considered for the assessment. Based on the comparisons with the national [AQCR (Air Quality Control Regulation). Ministry of Environment (MOE), Ankara. Official Newspaper 19269; 1986.] and a number of international [WHO (World Health Organization). Guidelines for Air Quality. Geneva; 2000. Downloaded in January 2006, website: http://www.who.int/peh/; EU (European Union). Council Directive 1999/30/EC relating to limit values for sulfur dioxide, nitrogen dioxide and lead in ambient air. Of J Eur Communities L 163: 14-30; 29.6.1999; EU (European Union). Council Directive 2002/3/EC relating to ozone in ambient air. Of J Eur Communities. L 67: 14-30; 9.3.2002.; USEPA (U.S. Environmental Protection Agency). National Ambient Air Quality Standards (NAAQS). Downloaded in January 2006, website: http://www.epa.gov/ttn/naaqs/] ambient air standards, among all the pollutants studied, only the annual average SO(2) concentration was found to exceed one specific limit value (EU limit for protection of the ecosystem). A part of the data (VOC/NO(x) ratio), for determining the effects of photochemical interactions, indicated that VOC-limited regime was prevailing throughout the city.     

Characteristics and health implications of fine and coarse particulates at roadside, urban background and rural sites in UK

Recent studies have pointed to evidence that fine particles in the air could be significant contributors to respiratory and cardiovascular diseases and mortality. Epidemiologists looking at the health effects of particulate pollution need more information from various receptor locations to improve the understanding of this problem. Detailed information on temporal, spatial and size distributions of particulate pollution in urban areas is also important for air quality modellers as well as being an aid to decision and policy makers of local authorities. This paper presents a detailed analysis of temporal and seasonal variation of PM(10) and PM(2.5) levels at one urban roadside, one urban background and one rural monitoring location. Levels of PM(10), PM(2.5) and coarse fraction of particulates are compared. In addition, particulate levels are compared with NO(2) and CO concentrations. The study concludes that PM(10) and PM(2.5) are closely related at urban locations. Diurnal variation in PM(2.5)/PM(10) ratio shows the influence of vehicular emission and movement on size distribution. This ratio is higher in winter than in summer, indicating a build-up or longer residence time of finer particulates or washout due to wet weather in winter. In the second part of this study, a disease burden analysis is carried out based on the dose-response relationships recommended by the UK Committee on the Medical Effects of Air Pollution. The disease burden analysis indicates that if Marylebone Road (MR) levels of PM(10) were prevalent all over London, it will result in around 2.5% increase in death rates due to all causes. Whereas, if Bloomsbury (BB) levels were prevalent in London, which is more likely to occur as this is more representative of the urban background environment to which people in London are likely to be exposed, the corresponding increase would be around 1.7%. Considering this, in London, at Bloomsbury levels, 973 deaths and 1515 respiratory hospital admissions (RHA) are attributable to PM(10) while 2140 RHA are attributable to NO(2). After deducting the disease burden due to background levels at Rochester (RC), PM(10) emission caused by anthropogenic activities in London equates to 273 additional deaths and 410 additional RHA, while NO(2) account for additional 1205 incidences of RHA.     

长江经济带PM_(2.5)时空特征及影响因素研究

大气细颗粒物(PM_(2.5))因其对空气环境质量乃至人类健康的巨大危害而逐渐引起学者们的关注。本文以我国综合实力最强、战略支撑作用最为突出的区域之一——长江经济带为研究对象,基于城市级空气质量监测数据,运用地理学时空分析与GIS可视化方法探索并呈现了2015年长江经济带PM_(2.5)的时空分布特征及其演变规律;在此基础上,结合空间回归模型考察了PM_(2.5)浓度与区域城市发展之间的内在关系。结果表明,就空间特征而言,长江中下游地区PM_(2.5)污染较长江上游地区更为严重,长江北岸地区比长江南岸地区更为严重;PM_(2.5)高浓度集聚地带主要位于鄂皖苏大部分地区,与空气质量较佳的云南及其周边地区呈"对角"分布状态。长江经济带内城市间PM_(2.5)浓度存在着显著的正向空间自相关,且自相关性随距离增大而不断减弱,其门槛尺度约为900 km;在这一范围内,PM_(2.5)空间集聚效应较为明显。就时间特征而言,冬季PM_(2.5)浓度相对较高,春秋两季次之,夏季空气质量最好;各地区浓度分布在年初相对离散,后有所趋同。此外,PM_(2.5)与其他类型的大气污染物(如SO2、NO2、O3)浓度两两之间均存在着显著的正相关性,暗示大气污染物从原发污染演变为二次污染,形成恶性循环。空间回归分析结果表明,PM_(2.5)污染随经济发展水平的提高呈现先上升后下降的趋势,在一定程度上支持了"环境库兹涅兹曲线"假说;且人口密度、公共交通运输强度均在不同程度上导致长江经济带PM_(2.5)浓度的升高。最后,从区域性联防联控、不同类型大气污染物协同治理、促进经济发展方式转型等方面为长江经济带的大气环境治理提出切实可行的政策建议。