GIS技术在城区大气降尘污染分区评价中的应用

应用地理信息系统（ＧＩＳ）技术分析了焦作市城区大气降尘污染状况。根据１９９５年城区降尘实测数据,绘制了降尘量等值线图,分析了城区降尘污染持的空间分布特征,引入降尘污染指数,将降尘污染程度做了六级划分,并利用ＡＲＣ／ＩＮＦＯ软件进行图像处理,生成拓扑关系,从而对焦作城区降尘污染程度进行了分区和评价。     

Observed chemical characteristics of long-range transported particles at a marine background site in Korea

Deokjeok Island is located off the west coast of the Korean Peninsula and is a suitable place to monitor the long-range transport of air pollutants from the Asian continent. In addition to pollutants, Asian dust particles are also transported to the island during long-range transport events. Episodic transport of dust and secondary particles was observed during intensive measurements in the spring (March 31-April 11) and fall (October 13-26) of 2009. In this study, the chemical characteristics of long-range-transported particles were investigated based on highly time-resolved ionic measurements with a particle-into-liquid system coupled with an online ion chromatograph (PILS-IC) that simultaneously measures concentrations of cations (Li+, Na , NH4+, K+, Ca2+, Mg2+) and anions (F-, C1-, NO3-, SO42-). The aerosol optical thickness (AOT) distribution retrieved by the modified Bremen Aerosol Retrieval (M-BAER) algorithm from moderate resolution imaging spectroradiometer (MODIS) satellite data confirmed the presence of a thick aerosol plume coming from the Asian continent towards the Korean peninsula. Seven distinctive events involving the long-range transport (LRT) of aerosols were identified and studied, the chemical components of which were strongly related to sector sources. Enrichment of acidic secondary aerosols on mineral dust particles, and even of sea-salt components, during transport was observed in this study. Backward trajectory, chemical analyses, and satellite aerosol retrievals identified two distinct events: a distinctively high [Ca2++Mg2]/[Na+] ratio (>2.0), which was indicative of a preprocessed mineral dust transport event, and a low [Ca2++Mg2+]/[Na+] ratio (<2.0), which was indicative of severe aging of sea-salt components on the processed dust particles. Particulate C1- was depleted by up to 85% in spring and 50% in the fall. A consistent fraction of carbonate replacement (FCR) averaged 0.53 in spring and 0.55 in the fall. Supporting evidences of C1- enrichment on the marine boundary layer prior to a dust front were also found. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of the Air & Waste Management Association for sector and air mass classifications of clean and LRT cases.     

An analysis of seasonal surface dust aerosol concentrations in the western US (2001–2004): Observations and model predictions

Long-term surface observations indicate that soil dust represents over 30% of the annual fine (particle diameter less than 2.5 μm) particulate mass in many areas of the western US; in spring and summer, it represents an even larger fraction. There are numerous dust-producing playas in the western US, but surface dust aerosol concentrations in this region are also influenced by dust of Asian origin. This study examines the seasonality of surface soil dust concentrations at 15 western US sites using observations from the Interagency Monitoring of PROtected Visual Environments (IMPROVE) network from 2001 to 2004. Average soil concentrations in particulate matter less than 10 μm in diameter (PM₁₀) were lowest in winter and peaked during the summer months at these sites; however, episodic higher-concentration events (>10 μg m⁻³) occurred in the spring, the time of maximum Asian dust transport to the western US. Simulated surface dust concentrations from the Navy Aerosol Analysis and Prediction System (NAAPS) suggested that long-range transport from Asia dominates surface dust concentrations in the western US in the spring, and that, although some long-range transport does occur throughout the year (1–2 μg m⁻³), locally generated dust plays a larger role in the region in summer and fall. However, NAAPS simulated some anomalously high concentrations (>50 μg m⁻³) of local dust in the fall and winter months over portions of the western US. Differences between modeled and observed dust concentrations were attributed to overestimation of total observed soil dust concentrations by the assumptions used to convert IMPROVE measurements into PM₁₀ soil concentrations, lack of inhibition of model dust production in snow-covered regions, and lack of seasonal agricultural sources in the model.     

Dust storm frequency and its relation to climate changes in Northern China during the past 1000 years

Dust storm events and their relation to climate changes in Northern China during the past 1000 years were analyzed by using different paleoclimate archives such as ice cores, tree rings, and historical documents. The results show that in the semiarid region, the temperature and precipitation series were significantly negatively correlated to the dust storm frequency on a decadal timescale. Compared with temperature changes, however, there was a closer correlation between precipitation changes and dust storm events on a centennial timescale. At this timescale, precipitation accounts for 40% of the variance of dust fall variations during the last 1700 years, inferring precipitation control on the formation of dust storms. In the western arid region, both temperature and precipitation changes are important forcing factors for the occurrence of dust storms in the region on a centennial timescale. In the eastern arid region, the relationship between dust storm events and climate changes are similar like in the semiarid region. As a result, the effects of climate change on dust storm events were manifested on decadal and centennial timescales during the last millennium. However, there is a phase shift in the relation between climate change and the dust storm frequency. A 1400 years reconstruction of the strength of the Siberian High reveals that long-term variations of spring Siberian High intensity might provide a background for the dynamic conditions for the frequency of historical dust storm events in Northern China.     

The impact of transpacific transport of mineral dust in the United States

We use a global chemical transport model (GEOS-Chem) to estimate the impact of transpacific transport of mineral dust on aerosol concentrations in North America during 2001. We have implemented two dust mobilization schemes in the model (GOCART and DEAD) and find that the best simulation of North American surface observations with GEOS-Chem is achieved by combining the topographic source used in GOCART with the entrainment scheme used in DEAD. This combination restricts dust emissions to year-round arid areas but includes a significant wind threshold for dust mobilization. The model captures the magnitude and seasonal cycle of observed surface dust concentrations over the northern Pacific. It simulates the free tropospheric outflow of dust from Asia observed in the TRACE-P and ACE-Asia aircraft campaigns of spring 2001. It reproduces the timing and distribution of Asian dust outbreaks in North America during April–May. Beyond these outbreaks we find persistent Asian fine dust (averaging 1.2 μg m⁻³) in surface air over the western United States in spring, with much weaker influence (0.25 μg m⁻³) in summer and fall. Asian influence over the eastern United States is 30–50% lower. We find that transpacific sources accounted for 41% of the worst dust days in the western United States in 2001.     

Using Si depletion in aerosol to identify the sources of crustal dust in two Chinese megacities

Depletion of Si in transported dust has been recognized for many years. It can be used to distinguish between transported and local dust in cities, although it rarely has been. Here we use the variations of the Si/Al ratio in 15 months of continuous PM_2.5 samples at Beijing (northern China) and Chongqing (southwestern China) to reveal the seasonal patterns of their dust sources. For both cities, peaks of concentration for Si and Al in PM_2.5 corresponded with minima of Si/Al, and could often be linked to pulsed air flow from deserts to the northwest. With significant depletion (up to 80%) and homogeneous distribution at urban and rural sites, Si/Al showed a clear seasonal evolution, which decreased from spring to summer, increased from fall to winter, and collapsed during Chinese Spring Festival, indicating the dominance of transported dust, local fugitive dust and firework influence, respectively. The low ratios implied that desert dust is a common source during spring at Chongqing, whereas its presence during cold season at Beijing was also more frequent than expected. Failing to recognize the depletion of Si may lead to an overestimate of desert dust by 15%–65% when using the average abundance of Al in crust (6%–8%), as in previous studies. The difference in Si/Al ratio between local and transported dust implies that >60% of the dust at Beijing came from outside the city during the springs of 2004–2006. This result can help resolve the contradictory findings on this topic that have been presented earlier.     

Fusion of SeaWiFS and TOMS satellite data with surface observations and topographic data during extreme aerosol events.

Spaceborne sensors allow near-continuous aerosol monitoring throughout the world. This paper illustrates the fusion of Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) and TOMS satellite data with surface observations and topographic data during four extreme aerosol events: (1) the April 1998 Asian dust storm that impacted the west coast of North America, (2) the May 1998 Central American forest fire smoke that impacted eastern North America, (3) the intense fall 1999 northern California fires, and (4) the massive February 2000 Sahara dust storm. During these dust and smoke events, the aerosol was visualized on true color SeaWiFS images as a distinct yellowish dye, the result of the aerosol increasing the reflectance of darker surfaces (ocean and land) and decreasing the reflectance of clouds. TOMS imagery also indicated increased aerosol absorption in the affected areas, while surface monitors measured major reductions in visual range. Fusing these data aids in the determination of the aerosol's spatial, temporal, and optical properties and provides supporting evidence for characterizing what is being visualized as dust or smoke. A 3-dimensional perspective of the events is obtained when incorporating topographic data and provides insight into the vertical properties of the aerosol plumes.     

Fusion of SeaWiFS and TOMS Satellite Data with Surface Observations and Topographic Data during Extreme Aerosol Events

ABSTRACT

Spaceborne sensors allow near-continuous aerosol monitoring throughout the world. This paper illustrates the fusion of Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) and TOMS satellite data with surface observations and topographic data during four extreme aerosol events: (1) the April 1998 Asian dust storm that impacted the west coast of North America, (2) the May 1998 Central American forest fire smoke that impacted eastern North America, (3) the intense fall 1999 northern California fires, and (4) the massive February 2000 Sahara dust storm. During these dust and smoke events, the aerosol was visualized on true color SeaWiFS images as a distinct yellowish dye, the result of the aerosol increasing the reflectance of darker surfaces (ocean and land) and decreasing the reflectance of clouds. TOMS imagery also indicated increased aerosol absorption in the affected areas, while surface monitors measured major reductions in visual range. Fusing these data aids in the determination of the aerosol's spatial, temporal, and optical properties and provides supporting evidence for characterizing what is being visualized as dust or smoke. A 3-dimensional perspective of the events is obtained when incorporating topographic data and provides insight into the vertical properties of the aerosol plumes.     

Uptake of PAHs by cabbage root and leaf in vegetable plots near a large coking manufacturer and associations with PAHs in cabbage core

Samples of ambient air (including gaseous and particulate phases), dust fall, surface soil, rhizosphere soil, core (edible part), outer leaf, and root of cabbage from eight vegetable plots near a large coking manufacturer were collected during the harvest period. Concentrations, compositions, and distributions of parent PAHs in different samples were determined. Our results indicated that most of the parent PAHs in air occurred in the gaseous phase, dominated by low molecular weight (LMW) species with two to three rings. Specific isomeric ratios and principal component analysis were employed to preliminarily identify the local sources of parent PAHs emitted. The main emission sources of parent PAHs could be apportioned as a mixture of coal combustion, coking production, and traffic tailing gas. PAH components with two to four rings were prevailing in dust fall, surface soil, and rhizosphere soil. Concentrations of PAHs in surface soil exhibited a significant positive correlation with topsoil TOC fractions. Compositional profiles in outer leaf and core of cabbage, dominated by LMW species, were similar to those in the local air. Overall, the order of parent PAH concentration in cabbage was outer leaf > root > core. Partial correlation analysis and multivariate linear stepwise regression revealed that PAH concentrations in cabbage core were closely associated with PAHs present both in root and in outer leaf, namely, affected by adsorption, then absorption, and translocation of PAHs from rhizosphere soil and ambient air, respectively.     

干旱区地表石油污染物风蚀作用大气传输量估算研究

通过焉耆盆地石油开发区石油污染物水环境污染途径特点的分析 ,认为落地油将通过风蚀作用由大气传输以降尘的形式落入水体 ,对水环境产生影响。本文以土壤侵蚀的风洞实验求得污染源源强 ,采用高斯模式对地表风蚀作用的传输量进行估算 ,进而对石油开发区落地油通过大气传输途径对区域水环境 (博斯腾湖 )的影响进行了预测 ,建立了相应的模型。为人们了解干旱区石油污染物风蚀作用水环境污染影响提供了初步依据 ,对干旱区湖泊石油污染的全面防治提供了科学范式     

Reconciliation and interpretation of the Big Bend National Park light extinction source apportionment: results from the Big Bend Regional Aerosol and Visibility Observational Study--part II

The recently completed Big Bend Regional Aerosol and Visibility Observational (BRAVO) Study focused on particulate sulfate source attribution for a 4-month period from July through October 1999. A companion paper in this issue by Schichtel et al. describes the methods evaluation and results reconciliation of the BRAVO Study sulfate attribution approaches. This paper summarizes the BRAVO Study extinction budget assessment and interprets the attribution results in the context of annual and multiyear causes of haze by drawing on long-term aerosol monitoring data and regional transport climatology, as well as results from other investigations. Particulate sulfates, organic carbon, and coarse mass are responsible for most of the haze at Big Bend National Park, whereas fine particles composed of light-absorbing carbon, fine soils, and nitrates are relatively minor contributors. Spring and late summer through fall are the two periods of high-haze levels at Big Bend. Particulate sulfate and carbonaceous compounds contribute in a similar magnitude to the spring haze period, whereas sulfates are the primary cause of haze during the late summer and fall period. Atmospheric transport patterns to Big Bend vary throughout the year, resulting in a seasonal cycle of different upwind source regions contributing to its haze levels. Important sources and source regions for haze at Big Bend include biomass smoke from Mexico and Central America in the spring and African dust during the summer. Sources of sulfur dioxide (SO2) emissions in Mexico, Texas, and in the Eastern United States all contribute to Big Bend haze in varying amounts over different times of the year, with a higher contribution from Mexican sources in the spring and early summer, and a higher contribution from U.S. sources during late summer and fall. Some multiple-day haze episodes result from the influence of several source regions, whereas others are primarily because of emissions from a single source region.     

APCA TC-1 Particulate Committee Informative Report No. 7

This document has been prepared to assist a prospective purchaser in the specification, purchase, and performance evaluation of all designs of Industrial baghouses (fabric filter-type dust collectors). A secondary, but essential, goal is to insure that the prospective purchaser and equipment manufacturer have a commonly understood vocabulary to prevent misunderstandings.     

Alteration in antioxidant status in slow and fast alleles of EPHX1 gene polymorphisms among wood workers

Environmental Science and Pollution Research - Occupational wood dust exposure may be associated with various health effects, especially in wood industry. These effects may be due to inducing...     

Studies into the formation of dioxins in the sintering process used in the iron and steel industry. 1. Characterisation of isomer profiles in particulate and gaseous emissions

Dioxin analyses using a DB5MS chromatography column are presented for samples of dust from an electrostatic precipitator and emissions from the main stack of a UK sinter plant. The analyses have been repeated using the SP2331 column, for which the elution order has been determined for the whole range of tetra to octachlorodibenzo-p-dioxins and dibenzofurans, and which provides a larger degree of separation than the DB5MS column. Polychlorinated dibenzofurans are present in significantly larger amounts in both the dust and stack emissions, and are the main contributors to the I-TEQ. Analysis using the SP2331 column for dioxins show considerable similarity to those of Bacher et al. for soot from a wood-burning fire, but differ markedly from those of Addink et al. for simulation of waste incineration. The similarities to Bacher's results are less for the dibenzofurans. Comparison of absolute concentrations with reported vapour pressures shows the retention of significant dioxin in the dust to involve mechanisms other than pure condensation.     

<Emphasis Type="Bold">Tracing lead contamination in foods in the city of Kolkata,India</Emphasis>

Lead isotopic ratios (LIR) of eight common food items, street dust, coal, diesel, sediments, lead ore and rainwater from India have been reported for the first time in this paper. This study characterized the source and extent of lead pollution in the different foodstuff consumed in Kolkata, a major metropolis of eastern India. The atmospheric lead input to the food items, sold openly in busy roadside markets of the city, has been quantified. The mean 207/206 and 208/206 LIRs of the eight food items ranged from 0.8847 to 0.8924 and 2.145 to 2.167, respectively. Diesel had the highest mean 207/206 and 208/206 values of 0.9015 and 2.1869, respectively, apart from the lead ore. The food items had a mean lead concentration between 3.78 and 43.35 mg kg^?1. The two ratio scatter plots of all the different environmental matrices were spread linearly between the uncontaminated Ichapur sediment and diesel. The 207/206 LIRs of the coal with a mean of 0.8777 did not fall in the linear trend, while the street dust and food samples overlapped strongly. The rainwater sample had a 207/206 LIR of 0.9007. Contaminated sediments in Dhapa, the repository of the city’s municipal garbage, had a mean 207/206 LIR of 0.8658. The corresponding value obtained from the sewage-fed vegetable grown there was 0.8058. The present study indicated that diesel was one of the main contributor to Pb pollution. The atmospheric lead contribution to the food items was in the range of 68.48–86.66 %.     

机动车单车扬尘浓度分布规律的模拟

为了掌握汽车扬尘中PM10污染分布特征,采用数值模拟的方法对汽车扬尘PM10浓度分布规律及其影响因素进行了研究,分析了车速、积尘负荷对汽车扬尘PM10浓度的影响.结果表明,车速与扬尘运移速率成正比,且车速在20～60 km/h范围内与扬尘高度近似成线性分布;积尘负荷与汽车扬尘PM10平均浓度同比例变化.     

Variation of dust layer height in the northern Taklimakan Desert in April 2002

LIDAR observations were conducted in the northern Taklimakan Desert to investigate the vertical distribution of dust in April 2002. During the observation period, a dust outbreak occurred on 13 April, remaining over the desert for several days. Despite only slight variations being observed in dust layer height before the dust event, marked diurnal variation in dust layer height was observed after the dust event. In this study, we conducted two numerical simulations to investigate differences in the variation exhibited by the dust layer heights before and after the dust event, and assessed the influence of meteorological conditions on this variation. The simulated results show that the clearly diurnal variation in dust layer height is strongly influenced by local circulation which is affected by the characteristic topography and synoptic conditions of the Tarim Basin.     

Southeastward transport of Asian dust: Source,transport and its contributions to Taiwan

Atmospheric Aluminum measured in northern Taiwan from 2003 to 2006 is used as a dust tracer, from which dust concentrations are derived, and major Asian dust events are determined. The source locations for the major dust events are traced back and identified, and the processes leading to the southeastward transport of Asian dust is investigated. The derived dust concentrations are compared to the local PM₁₀ (particle with size less than 10 μm) concentrations, and the impacts of Asian dust on the air quality of Taiwan are quantified.According to the backward trajectory and dust observation analyses, most of the southeastward transport of major Asian dust events originate from Mongolia and Inner Mongolia in northern China, and only one out of 16 events is generated from western China. Modeling studies and weather analyses of dust events suggest that the southeastward transport of Asian dust is usually generated behind a surface front and transported downwind behind the associated upper level trough. The associated upper level trough is usually deep, in which the northwesterly wind behind the trough favors the southeastward transport of dust to lower latitudes. Dust transported to Taipei generally occur during periods of large-scale subsidence.Asian dust contributes about 15 μg m^?3 of aerosol particles to northern Taiwan during winter monsoon, which accounts for about 24–30% of the PM₁₀ concentrations to the northern Taiwan. The contributions of Asian dust are raised pronouncedly to about 60–70% during major dust events. The impacts of Asian dust on Taiwan's air quality are most substantial in December. The Asian dust impacts decrease in other months, but still remain at around 30% in the late winter to early spring.     

以废纸为原料制备煤尘抑制剂的合成及应用

采用碱化、醚化法制备了以废纸为原料的煤尘抑制剂,借助FTIR、SEM、TG-DTA及XRF等手段对合成物进行了表征,并将其用于抑制煤尘进行性能测试。结果表明,羧甲基纤维素的取代度为0.69;选用羧甲基纤维素含量为0.5g/mL的煤尘抑制剂进行应用实验,效果最佳。9 h内,喷洒含有羧甲基纤维素的煤尘抑制剂的煤样表面已经结壳,抗七级风,抑尘率在130 h都可保持在99%以上。在较高温燃烧条件下,煤尘抑制剂以H2O和CO2的形式失去,不会产生有害物质。     

破碎站粉尘逸散规律及降尘技术的数值模拟及其应用

针对露天矿破碎站粉尘污染严重、治理技术中存在的缺陷,提出了超声波雾化喷雾降尘技术。以平朔安家岭煤矿为例,根据破碎站区域粉尘污染情况,应用数学模型对破碎站粉尘逸散规律进行解算,将模拟结果与现场实测数据对比,确定对卸载坑采用150~300μm雾滴粒径和对破碎机各产尘点采用1~10μm雾滴粒径的机体梁上外喷雾方式,通过对采取治理方案后破碎站粉尘浓度逸散的数值模拟和现场实际应用后的测试数据,显示全尘和呼吸性粉尘降尘效率分别达到94%和82%。结果表明,超声波喷雾降尘技术能有效降低破碎站粉尘浓度,保障了作业人员工作环境和安全。