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1.
Air pollutants can be transported to the pristine regions such as the Tibetan Plateau,by monsoon and stratospheric intrusion.The Tibetan Plateau region has limited local anthropogenic emissions,while this region is influenced strongly by transport of heavy emissions mainly from South Asia.We conducted a comprehensive study on various air pollutants(PM2.5,total gaseous mercury,and surface ozone)at Nam Co Station in the inland Tibetan Plateau.Monthly mean PM2.5 concentration at Nam Co peaked in April before monsoon season,and decreased during the whole monsoon season(June-September).Monthly mean total gaseous mercury concentrations at Nam Co peaked in July and were in high levels during monsoon season.The Indian summer monsoon acted as a facilitator for transporting gaseous pol-lutants(total gaseous mercury)but a suppressor for particulate pollutants(PM2.5)during the monsoon season.Different from both PM2.5 and total gaseous mercury variabilities,surface ozone concentrations at Nam Co are primarily attributed to stratospheric intrusion of ozone and peaked in May.The effects of the Indian summer monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau are complex and require further studies.  相似文献   

2.
苏志华  韩会庆  陈波 《中国岩溶》2020,39(3):442-452
选取贵阳市10个空气质量监测站发布的PM2.5、PM10、SO2、NO2、CO和O3实时浓度数据，通过时间序列分析法和插值法研究贵阳市大气污染物的时空变化和复合污染特征。结果表明:（1）贵阳市2014-2018年主要污染物PM2.5和PM10的年平均浓度逐渐下降，光化学污染物O3年平均浓度有所增加，空气质量逐渐转好，环境治理取得明显效果；（2）2018-2019自然年PM2.5、PM10、NO2和O3在春季污染最严重，SO2和CO在冬季污染最严重，反映出污染源、阶段性燃料燃烧和二次离子生成等因素对不同污染物的影响不同；（3）PM2.5和PM10日变化特征为“午峰晚峰”型，峰值发生的时间因季节而异，主要由不同季节人类作息的起止时间不同所致，O3日变化为单峰型，夜间O3浓度较低，从早晨8:00点开始随着太阳辐射的增大和温度的升高，在15:00-16:00点左右达到峰值；（4）PM2.5的空间分布呈现出部分郊区和工业区较高，市中心居民区较低的特征，指示城市建设向郊区推进。O3浓度呈现出市区低、郊区高的空间分布特征，反映郊区植被覆盖好，释放的天然源VOCs促进了O3生成；（5）主要污染物O3与颗粒物PM2.5和PM10在春季造成的复合污染最为严重，在夏季O3与PM10造成一定程度的复合污染，在秋冬季O3浓度最低，O3与颗粒物不产生复合污染；一天之内同一时刻O3与颗粒物不会产生叠加从而造成复合污染。   相似文献   

3.
对2012年5月至2013年5月香港空气污染期间89个污染日的天气环流形势通过模糊聚类的方法进行统计分类,得到大陆冷高压型、入海高压型、东北部热带气旋型和南部热带气旋型4种天气类型。结合细颗粒物(PM2.5)及其主要组分、气态污染物的日变化特征以及气象参数的相关性分析不同天气型影响下的污染事件在不同季节的污染特征。入海高压型污染事件发生时PM2.5主成分中二次水溶性无机离子(SIA)的占比明显比其他类型高,尤其是硝酸铵,可能与该天气型造成的高相对湿度、低温度的大气环境有关,进一步研究发现,春季污染事件中二次水溶性无机离子的增长与其前体物的非均相氧化反应有关;秋季硫酸盐的增长与均相氧化反应相关;冬季受季风影响,污染物的跨界输送贡献较大。大陆冷高压天气型造成大范围的下沉运动,静稳大气易导致污染物的积累,在PM2.5主成分中二次水溶性无机离子和有机物(OM)占比均有增高,秋、冬季二次水溶性无机离子前体物的非均相氧化反应与有机物的光化学氧化反应是造成该污染特征的主要原因之一。在东北部热带气旋型污染事件中有机碳与元素碳质量浓度的比值(OC/EC)较高且同O3的相关性较好,说明光氧化反应生成二次有机物是造成PM2.5中有机物占比大幅增高的主要原因。由于受到降水和大风的冲刷、稀释,南部热带气旋污染事件持续时间短,有机碳与元素碳同源,光氧化反应贡献小,二次有机物含量少且二次水溶性无机离子的占比更高。对香港地区在不同天气型影响下大气污染特征进行的系统性统计和分析,加深了该地区气象条件对污染过程影响的认识。  相似文献   

4.
Motor vehicles emit a cocktail of pollutants and are a major contributor to ground-level air pollution, but little is known regarding the ecological impacts of air pollution from roads on the surrounding vegetation. Data are presented on vegetation at three sites adjacent to two major motorways in the UK, comprising two woodland sites and one blanket bog site. Surveys of oak and beech tree health (at the woodland sites) and species composition (at the blanket bog site) were undertaken along transects away from the motorway.  相似文献   

5.
《Comptes Rendus Geoscience》2007,339(11-12):721-733
The life cycle of pollutants is affected by chemical as well as meteorological factors, such as wind, temperature, precipitation, solar radiation. Therefore, climatic changes induced by anthropogenic emissions of greenhouse gases may be expected to have significant effects on air quality. Because of the spatial variability of the pollutant emissions and climate-change signals, these effects are particularly relevant at the regional to local scales. This paper first briefly reviews modelling tools and methodologies used to study regional climate-change impacts on air quality. Patterns of regional precipitation, temperature, and sea-level changes emerging from the latest set of general circulation model projections are then discussed. Finally, the specific case of climate-change effects on summer ozone concentrations over Europe is presented to illustrate the potential impacts of climate change on pollutant amounts. It is concluded that climate change is an important factor that needs to be taken into account when designing future pollution-reduction policies.  相似文献   

6.
Air pollution is the presence of pollutants in the atmosphere from anthropogenic or natural substances in quantities likely to harm human, plant or animal life; to damage human-made materials and structures; to bring about changes in weather or climate; or to interfere with enjoyment of life or property. With regard to the quality of air in most of the megacities of the world, vehicular air pollution plays an important role in deteriorating air quality. Air pollution in Tehran (Capital of the Islamic Republic of Iran) occurs in highly urbanized areas due to mobile anthropogenic sources which in-turn is hastened by unfavorable tohion sector is responsible for much of urban air pollution and can result in high ambient concentrations that harm people, structures, and environment. This paper examines and estimates the tonnage, concentrations and impacts of air pollutants along with control measures aimed at reducing the effect of pollutants released by transportation navigation, in Tehran.  相似文献   

7.
超低排放燃煤电厂一次颗粒物和黑碳实时排放特征   总被引：2，自引：0，他引：2  
燃煤电厂是大气一次污染物的重要排放源,其超低排放改造改变了大气颗粒物排放特征。为满足当前高时间分辨率排放清单构建的需要,燃煤电厂颗粒物实时排放质量浓度及关键组分比值亟需更新。本研究基于稀释通道采样系统,对某超低排放改造后的燃煤电厂开展实测,获得该燃煤电厂可吸入颗粒物(PM10)、细颗粒物(PM2.5)、超细颗粒物(PM1.0)和黑碳(BC)的实时排放质量浓度,更新各污染物排放因子,分析PM1.0/PM2.5、PM2.5/PM10和BC/PM2.5质量浓度比值(文中以上比值均为质量浓度比值)日变化。结果表明,上述污染物排放平均质量浓度分别为(5.0±6.0)mg/m^3、(5.0±5.9)mg/m^3、(4.9±5.9)mg/m^3和(36.6±28.3)μg/m^3;对应的排放因子分别为0.03 kg/t、0.03 kg/t、0.03 kg/t和0.2 mg/kg。该燃煤电厂颗粒物排放质量浓度表现出明显的日间变化,高值时段(20:30至次日10:30)PM2.5平均质量浓度是低值时段(10:30~20:30)的12.2倍,推测可能与不同时段的污染控制措施效率变动有关。作为不完全燃烧的产物,黑碳排放高值时段(06:00~12:00和14:30~19:00)的质量浓度是低值时段(00:00~05:00)相应值的1.5~2.4倍,推测与煤的添加和锅炉燃烧效率有关。颗粒物及组分质量浓度的日变化在构建高时间分辨率排放清单时需予以考虑。本研究实测所得PM2.5/PM10和BC/PM2.5比值分别为1.00±0.01和0.03±0.04,均远高于清单编制技术手册中推荐的燃煤电厂相应比值0.3和0.002,采用现有清单编制技术手册的相应比值可能低估了燃煤电厂细颗粒物和黑碳排放,需引起重视。  相似文献   

8.
文中利用电感耦合等离子质谱仪(ICP-MS)对《攻坚行动方案》实施后北京市环境大气PM2.5中微量元素组成特征进行研究。结果表明,《攻坚行动方案》实施后,北京市PM2.5中微量元素以Zn、Mn、Ba、Pb、Cr、Cu、Ti等7种元素为主,其中元素Zn含量最高。元素Zn、Cd、Tl、Cs、Rb的水溶性组分在总微量元素中占比超过80%,说明这些元素大部分以易溶于水的状态存在于PM2.5中。有趣的是,在PM2.5样品中微量元素的含量(10-6)随着PM2.5污染水平的升高而下降,而质量浓度(ng·m-3)随PM2.5污染水平的升高而升高。这说明单位质量PM2.5中微量元素的含量只与颗粒物的组成成分有关,与颗粒物浓度无关。采样期间PM2.5中的微量元素主要来源于土壤扬尘(48.27%)、燃烧源和工业排放(16.16%)、刹车和轮胎磨损(10.03%),其次是汽车尾气(5.84%)、建筑扬尘(4.88%)以及其他源(3.68%)。与攻坚行动前相比,PM2.5中微量元素的质量浓度有明显的降低,高污染等级的PM2.5样品中微量元素质量浓度的降幅最为明显,比攻坚行动前下降了80.3%。  相似文献   

9.
Pakistan is a developing country existing geographically at a pivoted location between two of the world’s largest pollution emitting countries (China and India) which adds to the severity of environmental issues faced by the country. These concerns include air pollution, climate change, and extreme weather situations prevailing in Pakistan. This increasing air pollution is deteriorating the health, threatening the food security and adding up its share to the already existing global warming. The initial step in devising a wide ranging, multifaceted, economically feasible, and sustainable solution to deal with the severity of this issue is the quantification of the air pollution and greenhouse gas emission in Pakistan. The GAINS model is one of the most comprehensive tools, dealing with the air pollutants and greenhouse gases covered by the Kyoto Protocol. This study has utilized this model to analyze the source-based anthropogenic emissions of air pollutants (NH3 and SO2), volatile organic compounds (VOCs), and greenhouse gases (CH4 and CO2), their impacts and abatement cost, for the duration of 1990–2030, in the Khyber Pakhtunkhwa and Balochistan regions of Pakistan. An overall increasing trend was observed during 1990–2030 for (a) air pollutants: NH3 (223.52–568.87kT/Y); SO2 (50.52–332.95kT/Y), (b) VOCs (121.76–246.81kT/Y), and (c) greenhouse gases: CO2 (7.83–62.45MT/Y) and CH4 (1120-2314kT/Y). The emission inventories created for all greenhouse gases together estimated the increase of 42.37 to 138.57 MTCO2eq. for greenhouse gases over the time duration of 1990–2030.  相似文献   

10.
《Atmósfera》2014,27(4):377-384
Clean air is a basic requirement for human health and wellbeing. The Kenya Meteorological Department has established air pollution monitoring activities in various sites in Nairobi, at Dagoretti Corner meteorological station and at Mount Kenya. Different pollutants are measured including ozone. The increased concentration of greenhouse gases in the atmosphere has influenced the weather and climate. This study examined the variations of surface ozone over Dagoretti Corner, Nairobi for a 12-month period ending July 2013, exactly one year after the start of data acquisition. The trend was studied using time series analysis of ozone concentration on both an hourly and monthly basis. The ozone data was then combined with meteorological data and temperature to find correlations between the two. Overall, the air quality of Nairobi, represented by Dagoretti Corner meteorological station is good as compared to the World Meteorological Organization ozone standards. The highest concentration of ozone is observed in the afternoon and the minimum at dawn on a daily basis. On seasonal scale, the highest levels are recorded in the cold months. This information helps to reduce exposure to the gas and thus to reduce its impacts on living things. The study recommends the reduction of exposure to the gas during the times when it has been observed to be highest in order to minimize its impacts.  相似文献   

11.
Logistics in China has grown rapidly; in 2015, the freight volume has reached 41 billion ton, increasing by 4.4% year-on-year. At the same time, the pollutant emissions from freight cars account for 70% of total emissions of motor vehicles, which severely affected the air quality. The purpose of this paper is to investigate the effect of logistics on air pollution; we used a new methodology based on vector autoregression of freight turnover, gross domestic product, and urban population. We selected Beijing as our test and created a model using time series data for the period 2000–2014. In this model, permanent residents, freight turnover, and SO2 emission were used as proxies for population size, logistic services, and degree of air pollution. Our analyses showed that the expansion of logistic services had the biggest effect on air pollution. Moreover, impulse response analysis revealed that logistic growth caused more serious air pollution over a short time, with an ongoing negative effect. GDP growth was only weakly correlated with air pollution, while urban population growth appeared to have little effect.  相似文献   

12.
Besides the enormous improvement of air quality in Germany due to the reduction of sulphur dioxide emissions in the last decades, high immissions of nitrogen oxides and fine particulate matter are frequently observed at traffic-rich urban sites. The changed chemical composition of air pollution requires a new investigation of its impact on historic buildings constructed of natural stone. In a pilot study a multi-disciplinary approach was chosen to obtain information on the actual pollution situation of historic buildings and monuments at traffic hotspots in Germany. The study concentrated on the two German cities of Munich and Mainz of different size, traffic volume and stone inventory. Dose–response functions were calculated to demonstrate the change of impact of different pollutants over the last three decades, and for comparison of traffic hotspots and housing areas of both cities. Numeric modelling on a city-scale was used to identify the historic buildings and monuments affected by elevated traffic immissions. Because a relevant part of these pollutants is dominated by short-range transport, the differences of wind speed and deposition rates were calculated using a street-scale 3D flow and dispersion model regarding traffic volume, wind regime and adjacent buildings. Finally, particulate matter was sampled at different positions of two buildings heavily exposed to traffic emissions. Individual particles were investigated by environmental scanning electron microscopy. After classification of the particles into different chemical groups, the fraction of traffic-induced particulate matter was quantified. Summarizing the results, it must be stated that soiling by traffic-related particulate matter, deposition of nitrates deriving from exhaust emission and other diffusely emitted components bear a severe damage potential for natural building stone at least locally at traffic-rich urban sites.  相似文献   

13.
北京市PM_(2.5)中主要重金属元素污染特征及季节变化分析   总被引：3，自引：0，他引：3  
利用2005年4月18日—2008年9月27日北京市中国地质大学(东门)采样点的PM2.5质量浓度变化与重金属Cd、Pb、As、Cu及Zn等污染特征,结合最新发布的《环境空气质量标准》(GB3095—2012),初步分析了近4年时间里北京市单点PM2.5的污染水平及主要重金属污染元素的变化特征,得出了一些有意义的认识。2005年春季—2008年春季期间PM2.5质量浓度为13.1～171μg/m3之间变化,平均浓度为65.6μg/m3,超过最新环境空气质量标准制定的PM2.5年平均浓度限值35μg/m3,北京市PM2.5污染形势依然严峻。奥运会及残奥会期间PM2.5的24 h质量浓度平均值为40.7μg/m3,没有超标。北京市PM2.5中的重金属元素含量及富集特征随着不同年份不同季节差别较大,典型的城市污染元素As在冬季质量浓度最高。对比环境空气质量标准的参考浓度限值发现,As元素的质量浓度在研究期间的年均值均超过了年平均浓度参考限值0.006μg/m3。化学分析结果显示人为污染是PM2.5中Cu、Cd、Pb、Zn、As重金属污染的主要来源,其中As污染需要引起足够重视。研究结果对于北京市大气污染防治具有一定的借鉴意义。  相似文献   

14.

In arid and semiarid regions from the southwestern USA and vast areas of northwestern Mexico, Santa Ana wind events modify the environment with high temperatures, very low humidity, and dust storms representing a recurrent phenomenon that triggers asthma and other respiratory diseases. While research has emphasized Santa Ana wind effects on the USA side, northwestern Mexico has been less investigated. Numerical modeling of a severe dust storm in November 2018, applying the Weather Research and Forecasting model coupled with a chemistry module (WRF-Chem), revealed that erosion, transport, and dust storms extend along the peninsula and the Gulf of California. Santa Ana winds eroded large areas, transported desert conditions to urban zones, causing high dust concentrations and reducing the relative humidity below 10%, deteriorating climatic conditions favorable to wellness. In Tijuana, Mexicali, Ensenada, San Diego, and Los Angeles, PM10 and PM2.5 concentrations (particle matter with diameter below 10 µm and 2.5 µm) reached values over 2000 µg/m3 for PM10, with daily mean concentrations well above national standards, leading to poor air quality and representing a health threat even in short-term exposure. This Santa Ana event transported dust particles several hundreds of kilometers over urban areas, the Gulf of California, and the Pacific Ocean. Severe soil deterioration was simulated within the study area, reaching dust emissions above 700,000 t, including croplands from the northern part of Baja California and Sonora's coastal area.

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15.
Air quality monitoring was performed at the measuring sites in the urban-industrial and suburban zone during the period 2005–2007 in Bor (Serbia). Arsenic, lead, cadmium, copper and sulphur dioxide are predominantly of industrial origin as a result of copper production in the study area. The smelter, which is a part of the Mining-Metallurgical Complex Bor, is the major pollution source. As and SO2 are the pollutants which pose the biggest threat for the inhabitants of the Bor area, since the measured concentrations exceed the proposed limit values. The obtained concentrations showed that the endangered areas are in close vicinity of the smelter, as well as in the directions of the prevailing winds. By grouping these pollutants into separate clusters, the results of cluster analysis confirmed high loads of As and SO2 in the air. The results of principal component analysis showed that copper production has major influence on air pollution.  相似文献   

16.
Due to its negative impact on the living environment of human beings, ambient air pollution has become a global challenge to human health. In this study, surface observations of six criteria air pollutants, including PM2.5, PM10, SO2, NO2, CO and O3, were collected to investigate the spatial and temporal variation in the Beijing–Tianjin–Hebei (BTH) region during 2013–2016 and to explore the relationships between atmospheric pollutants and meteorological variables using quantile regression model (QRM) and multiple linear regression model (MLRM). The results show that BTH region has experienced significant air pollution, and the southern part generally has more severe conditions. The annual average indicates clear decreasing trends of the particulate matters, SO2 and CO concentrations over the last 4 years and slight increasing trends of NO2 and O3 in several cities. The seasonal and monthly characteristics indicate that the concentrations of five species reach their maxima in the winter and their minima in the summer, whereas O3 has the opposite behaviour. Finally, the pseudo R2 values show that the QRMs have the best performance in the winter, followed by spring, fall, and summer. Specifically, all the meteorological factors have significant impacts on air pollution but change with pollutants and seasons. The MLRM results are generally consistent with the QRM results in all seasons, and the inconsistencies are more common in the fall and winter. The results of this research provide foundational knowledge for predicting the response of air quality to climate change in the BTH region.  相似文献   

17.
北京市冬季大气PM2.5中多氯联苯的污染水平与分布   总被引：3，自引：2，他引：1  
2008年1月同时采集了北京市市区/交通干道(中国地质大学(北京)东门及测试楼顶)、工业区(首钢集团焦化厂、高井热电厂)和背景点(十三陵)大气颗粒物PM2.5样品。依据US EPA 1668A 方法,采用同位素稀释、高分辨率气相色谱/高分辨率质谱(HRGC/MS)联用技术,对比分析了PM2.5中19种多氯联苯(PCBs)的质量浓度、分布特征及来源。结果表明, 5个采样点PM2.5的质量浓度范围为101.85～145.57 μg/m3,日均值为119 μg/m3,比美国1997年制定的日均标准(65 μg/m3 )高83%,属严重污染。 PM2.5中∑PCBs的质量浓度和毒性当量(TEQ)分别为7.2～16.2 pg/m3 (平均值10.9 pg/m3)、8.29～17.81 fgWHO-TEQ/m3 (平均值13.58 fgWHO-TEQ/m3),与其他国家和地区比较,北京市大气PCBs的污染处于较低水平。PCBs最高浓度出现在工业区,其次是市区,背景点最低,化石燃料的不完全燃烧是北京市PCBs的主要来源。研究成果将为北京市大气环境中持久性有机污染物(POPs)的污染防治提供科学依据。   相似文献   

18.
South Asia is the subregion of Asia with the most neighbors of China. Although the high mountains in the Great Himalayas spatially separate South Asia from East Asia along the border of China’s autonomous region of Tibet, the geographical items such as mountains and rivers link the countries in South Asia with China, resulting in a special and complex geopolitical environment and relationship. In this geopolitical relationship, the transboundary rivers are becoming a key issue of this region in an era of increasing water stress. Depleted and degraded transboundary water supplies have the potential to cause social unrest and spark conflict within and between countries in South Asia, and complicate the geopolitical relationship among them. In addition, the increasing impacts from climate change and human activities will definitely bring many transboundary eco-environmental issues in this region, projecting a big challenge to regional stability and development. The key issues related to the water resources supplement and exploration require the transboundary rivers to be a positive role in regional water resources utility and exploration, and the result will definitely affect regional relationship and water security. How to handle these issues and challenges will be a question for the countries in this region with a long time. Currently, the “Belt and Road” Initiative represents an opportunity to build a shared vision for common prosperity through regional cooperation and is a way to inject new positive energy into world peace and development. In the light of this, the countries with transboundary rivers in South Asia must come together to construct a cooperative mechanism of water security, and adopt a win-win cooperation for the use of transboundary rivers under the principles of “equal”, “equitable” and “reasonable”.  相似文献   

19.
济宁市是位于华北平原大气污染传输通道上的工业城市,为研究其秋、冬季细颗粒物(PM2.5)的污染特征,在市区的3个站点进行了PM2.5的同步滤膜采样.采样期为2018年10月15日至2019年1月31日,涵盖非采暖期和采暖期(自2019年11月15日始),共270个小流量滤膜样品.研究结果表明,济宁市秋、冬季PM2.5平...  相似文献   

20.
The decline of lichens throughout Europe and elsewhere over the past two centuries is mainly attributable to increases in air pollution in general, and to sulphur dioxide in particular. The destructive role of other atmospheric pollutants, and indeed other factors, has either been masked by the overriding effects of sulphur dioxide or insufficiently appreciated due to the inadequacy of monitoring equipment. Research has shown that qualitative as well as quantitative changes in air pollution due to shifts in energy and transportation policies on the one hand and economic and legislative factors on the other over the past twenty years are having significant effects on lichen floras. The versatility of lichens in highlightning not only the existence but also the rise and fall in levels of these new pollution regimes over wide geographical areas is demonstrated by reference to the British Isles.  相似文献   

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