Aerosol size distribution and mass concentration measurements in various cities of Pakistan

During March and April 2010 aerosol inventories from four large cities in Pakistan were assessed in terms of particle size distributions (N), mass (M) concentrations, and particulate matter (PM) concentrations. These M and PM concentrations were obtained for Karachi, Lahore, Rawalpindi, and Peshawar from N concentrations using a native algorithm based on the Grimm model 1.109 dust monitor. The results have confirmed high N, M and PM concentrations in all four cities. They also revealed major contributions to the aerosol concentrations from the re-suspension of road dust, from sea salt aerosols, and from vehicular and industrial emissions. During the study period the 24 hour average PM(10) concentrations for three sites in Karachi were found to be 461 μg m(-3), 270 μg m(-3), and 88 μg m(-3), while the average values for Lahore, Rawalpindi and Peshawar were 198 μg m(-3), 448 μg m(-3), and 540 μg m(-3), respectively. The corresponding 24 hour average PM(2.5) concentrations were 185 μg m(-3), 151 μg m(-3), and 60 μg m(-3) for the three sites in Karachi, and 91 μg m(-3), 140 μg m(-3), and 160 μg m(-3) for Lahore, Rawalpindi and Peshawar, respectively. The low PM(2.5)/PM(10) ratios revealed a high proportion of coarser particles, which are likely to have originated from (a) traffic, (b) other combustion sources, and (c) the re-suspension of road dust. Our calculated 24 hour averaged PM(10) and PM(2.5) concentrations at all sampling points were between 2 and 10 times higher than the maximum PM concentrations recommended by the WHO guidelines. The aerosol samples collected were analyzed for crustal elements (Al, Fe, Si, Mg, Ca) and trace elements (B, Ba, Cr, Cu, K, Na, Mn, Ni, P, Pb, S, Sr, Cd, Ti, Zn and Zr). The averaged concentrations for crustal elements ranged from 1.02 ± 0.76 μg m(-3) for Si at the Sea View location in Karachi to 74.96 ± 7.39 μg m(-3) for Ca in Rawalpindi, and averaged concentrations for trace elements varied from 7.0 ± 0.75 ng m(-3) for B from the SUPARCO location in Karachi to 17.84 ± 0.30 μg m(-3) for Na at the M. A. Jinnah Road location, also in Karachi.     

Chemical characteristics of aerosols and trace gas distribution over North and Central India

A field campaign on aerosol chemical properties and trace gases measurements was carried out along the Delhi-Hyderabad-Delhi road corridor (spanning about 3,200 km) in India, during February 1-29, 2004. Aerosol particles were collected on quartz and cellulose filters using high volume (PM(10)) sampler at various locations along the route (i.e., urban, semi-urban, rural, and forest areas) and have been characterized for major cations (Na(+), Ca(2+), Mg(2+), K(+), and NH (4) (+)), anions (Cl(-), NO (3)(-), and SO (4)(2-)), and heavy metals (Cu, Cd, Fe, Zn, Mn, and Pb). Simultaneously, we measured NO(2) and SO(2) gases. These species show large spatial and temporal variations. The ambient PM(10) concentration has been observed to be the highest (55 ± 4 μg m(-3)) near semi-urban areas followed by forest areas (48 ± 2 μg m(-3)) and in rural areas (44 ± 22 μg m(-3)). The concentrations of NO( x ) (NO(2)+NO) and SO(2) ranged from 16 to 69 μg m(-3) and 4 to 11 μg m(-3), respectively. Among anions, NO(3)(-) and SO(4) (2-) are the major constituents of PM(10). The urban and semi-urban sites showed enhanced concentrations of Fe, Zn, Mn, Cd, and Pb. This study provide information about atmospheric concentrations of various species in the northern to central India, which may be important for policy makers to better understand the air quality of the region.     

桂林市细颗粒物部分典型排放源的粒径谱及成分分析

采用在线单颗粒气溶胶质谱技术源解析方法,对桂林市PM2.5典型排放源的粒径和化学成分进行质谱分析,采集燃煤/燃气源、工业工艺源、扬尘源、油烟源4类共计7个典型排放源。结果表明,桂林市4类排放源细颗粒物的粒径分布为0.25~1.25μm,80%以上的细颗粒分布在0.2~1.0μm的小粒径范围,峰值约0.68μm。细颗粒物离子成分含有Na~+、Mg~+、K~+、NH~+4、Fe~+、Pb~+、Cd~+、V~+、Mn~+、Li~+、Al~+、Ca~+、Cu~+、Zn~+、Cr~+、CN~-、PO_3~-、NO_2~-、NO_3~-、Cl~-、SO_4~(2-)、SiO_3~-等成分,桂林市细颗粒物为元素碳、有机碳元素碳、有机碳、富锰颗粒、富铁颗粒、富钾颗粒、矿物质、左旋葡聚糖以及其他金属等9类。     

Influence of burning of fireworks on particle size distribution of PM<Subscript>10</Subscript> and associated Barium at Nagpur

Influence of burning of fireworks on particle size distribution of PM₁₀ and associated barium (Ba) were studied at a congested residential cum commercial area of Nagpur city, India. Sampling was carried out by cascade impactor having 50% cut-off aerodynamic diameters of <10, 9, 5.8, 4.7, 3.3, 2.1, 1.1, 0.7, and <0.4 μm, 2 days before diwali, during diwali, celebrations of marriage functions, and New Year’s Eve. Noticeably, increased levels of PM₁₀ and Ba were observed during diwali as compared to days before diwali and other activities. PM₁₀ levels were increased by four to nine times whereas Ba levels were increased by eight to 20 times higher in alveolar region, when compared with the levels observed before diwali. Probability of deposition of Ba mass in alveolar region varied between 14 and 27 ng/h with higher deposition when the burning of fireworks activity was lower near the site. Trimodal distribution of Ba was observed on the first 2 days of diwali at 0.4–2.1, 2.1–4.7, and 4.7 to less than PM₁₀ micrometer range. While on the third day, it appeared bimodal with 70% contribution in coarse fraction whereas on the fourth day, distribution appeared unimodal with 66% contribution in alveolar region (<0.4–1.1 μm). Distribution of Ba varied with respect to particle size, in accordance with the intensity of the fireworks used on different days and distance between the burning of firecrackers from the monitoring site.     

Indoor and outdoor concentrations of fine particles, particle-bound PAHs and volatile organic compounds in Kaunas, Lithuania

This complex study presents indoor and outdoor levels of air-borne fine particles, particle-bound PAHs and VOCs at two urban locations in the city of Kaunas, Lithuania, and considers possible sources of pollution. Two sampling campaigns were performed in January-February and March-April 2009. The mean outdoor PM(2.5) concentration at Location 1 in winter was 34.5 ± 15.2 μg m(-3) while in spring it was 24.7 ± 12.2 μg m(-3); at Location 2 the corresponding values were 36.7 ± 21.7 and 22.4 ± 19.4 μg m(-3), respectively. In general there was little difference between the PM concentrations at Locations 1 and 2. PM(2.5) concentrations were lower during the spring sampling campaign. These PM concentrations were similar to those in many other European cities; however, the levels of most PAHs analysed were notably higher. The mean sum PAH concentrations at Locations 1 and 2 in the winter campaign were 75.1 ± 32.7 and 32.7 ± 11.8 ng m(-3), respectively. These differences are greater than expected from the difference in traffic intensity at the two sites, suggesting that there is another significant source of PAH emissions at Location 1 in addition to the traffic. The low observed indoor/outdoor (I/O) ratios indicate that PAH emissions at the locations studied arise primarily from outdoor sources. The buildings at both locations have old windows with wooden frames that are fairly permissive in terms of air circulation. VOC concentrations were mostly low and comparable to those reported from Sweden. The mean outdoor concentrations of VOC's were: 0.7 ± 0.2, 3.0 ± 0.8, 0.5 ± 0.2, 3.5 ± 0.3, and 0.2 ± 0.1 μg m(-3), for benzene, toluene, ethylbenzene, sum of m-, p-, o-xylenes, and naphthalene, respectively. Higher concentrations of VOCs were observed during the winter campaign, possibly due to slower dispersion, slower chemical transformations and/or the lengthy "cold start" period required by vehicles in the wintertime. A trajectory analysis showed that air masses coming from Eastern Europe carried significantly higher levels of PM(2.5) compared to masses from other regions, but the PAHs within the PM(2.5) are of local origin. It has been suggested that street dust, widely used for winter sanding activities in Eastern and Central European countries, may act not only as a source of PM, but also as source of particle-bound PAHs. Other potential sources include vehicle exhaust, domestic heating and long-range transport.     

Study of size and mass distribution of particulate matter due to crop residue burning with seasonal variation in rural area of Punjab, India

Emission from field burning of agricultural crop residue is a common environmental hazard observed in northern India. It has a significant potential health risk for the rural population due to respirable suspended particulate matter (RSPM). A study on eight stage size segregated mass distribution of RSPM was done for 2 wheat and 3 rice crop seasons. The study was undertaken at rural and agricultural sites of Patiala (India) where the RSPM levels remained close to the National Ambient Air quality standards (NAAQS). Fine particulate matter (PM(2.5)) contributed almost 55% to 64% of the RSPM, showing that, in general, the smaller particles dominated during the whole study period with more contribution during the rice crop as compared to that of wheat crop residue burning. Fine particulate matter content in the total RSPM increased with decrease in temperature. Concentration levels of PM(10) and PM(2.5) were higher during the winter months as compared to that in the summer months. Background concentration levels of PM(10), PM(2.5) and PM(10-2.5) were found to be around 97 ± 21, 57 ± 15 and 40 ± 6 μg m(-3), respectively. The levels increased up to 66, 78 and 71% during rice season and 51, 43 and 61% during wheat crop residue burning, respectively. Extensive statistical analysis of the data was done by using pair t-test. Overall results show that the concentration levels of different size particulate matter are greatly affected by agricultural crop residue burning but the total distribution of the particulate matter remains almost constant.     

乌鲁木齐市可吸入颗粒物污染水平及其与气象因素的相关性分析

为了解可吸入颗粒物污染水平与气象因素之间的关系,从2008年9月—2010年2月采集乌鲁木齐市可吸入颗粒物样品,并对其随时间的变化特征及其与气象因素之间的相关性进行了统计分析。结果表明,采样时间内可吸入颗粒物中PM2.5和PM2.5-10的质量浓度的范围分别为38.2~468.7μg/m3和20.8~243.1μg/m3,平均浓度分别为134.2μg/m3和69.2μg/m3。可吸入颗粒物同时受几种气象因素的影响,其浓度与温度、能见度、风速呈负相关,与湿度呈正相关。     

一次连续在线观测分析天津市细颗粒物污染特征

根据2005年的5月17日—5月23日GR IMM(1.109#)谱分析仪在线观测结果考察天津市细颗粒物浓度和质量浓度特征。观测期间,天津市颗粒物数浓度平均值为1 124 cm-3,粒径分布为0.25μm~0.60μm,98.5%粒子的粒径0.65μm。同期PM10日均质量浓度值为204μg/m3,ρ(PM2.5)为104μg/m3,ρ(PM1.0)为82.9μg/m3。ρ(PM1.0)/ρ(PM2.5)超过80%,粒径1μm超细颗粒物为天津城市大气颗粒物的主要成分。     

2017年厦门金砖会晤期间PM2.5的化学特征及来源

为了探讨厦门金砖会晤期间的排放控制措施以及天气形势对大气颗粒物污染特征的影响,于2017年8月10日至9月10日对厦门气态污染物、细颗粒物(PM2.5)中的水溶性离子以及有机碳(OC)、元素碳(EC)等主要化学成分开展了高时间分辨率的在线监测。根据空气质量管控措施和天气形势将研究期分为6个阶段。管控前、管控期Ⅰ(非台风)和管控期Ⅱ(非台风) PM2.5质量浓度分别为(33. 12±9. 48)、(30. 30±17. 00)、(16. 01±4. 71)μg/m^3。管控期Ⅰ(台风)和管控期Ⅱ(台风) PM2.5质量浓度分别为(12. 40±3. 73)、(12. 45±3. 28)μg/m^3。结果表明:管控期Ⅰ(非台风)阶段受静稳天气的影响,管控效果削弱,PM2.5质量浓度下降幅度小;台风对颗粒物质量浓度下降的影响比管控更显著。管控初期,PM2.5中二次无机离子的质量浓度下降明显;台风对碳质组分质量浓度的影响不如无机组分显著。PMF源解析结果表明,二次无机源是PM2.5主要来源,随着管控措施的实行,扬尘源的贡献从21%降低到6%,而机动车源的贡献降幅不明显。台风期间SO4^2-、NO3^-、SO2、NO2以及硫酸盐氧化比值(SOR)均明显低于非台风期间,氮氧化比值(NOR)反而升高。台风和非台风期间NOR的日变化特征一致,NOR与阳离子的相关性分析结果表明,台风或高风速海风期间NOR与Na^+呈现很强的正相关性,说明海盐粒子可促进NO2非均相反应生成NO3-。     

Size distribution and seasonal variations of particle-associated organochlorine pesticides in Jinan, China

The concentrations of organochlorine pesticides (OCPs) in atmospheric particulate matter in Jinan, China, over the period from July 2009 to June 2010, were determined to study their pollution levels, compositions, size distribution and seasonal variations. All target compounds except endosulfan sulfate were detected. The annual average concentration of ∑18 OCPs was 92 ± 82 pg m(-3). Total HCH, total endrin, aldrin, endosulfan compounds and total DDT compounds were the primary components, accounting for approximately 27%, 20%, 16%, 14% and 10% of total OCPs, respectively. The annual mean ng g(-1) concentrations of ∑18 OCPs in PM(2.5), PM(5), PM(10) and TSP were 481 ± 190, 433 ± 161, 414 ± 158 and 264 ± 193, respectively, indicating that most OCPs tend to be strongly absorbed by fine air particles which were strongly related to a potential health risk. Distinct seasonal trends were found in OCPs concentrations with high concentrations appearing in November and March whereas low concentrations appeared in the summer, which were significantly positively correlated with particulate mass concentrations and Air Pollution Index (API). The high OCPs levels could be attributed to the seasonal usage, long-range atmospheric transport as well as adverse meteorological conditions.     

Composition, seasonal variation, and sources of PM10 from world heritage site Taj Mahal, Agra

Air samples for PM(10) (dp?相似文献   

Size Distribution of Aerosols (PM10) and Lead (Pb) near Traffic Intersections in Mumbai (India)

The size distribution of aerosols was measured near traffic intersections of Marol link road in air quality control region (AQCR1), which is a moderately industrial area and Dadar Khodad circle in AQCR2, which is a heavily commercial core of the Mumbai City. The reason behind selecting the two unidentical regions was to study the contribution from vehicles to the size separated PM10 and that of Pb. It is recognised that particulates in urban air are responsible for serious health effects. As very small particles are assumed to be important for the adverse health effects, the particle size distribution is thus an important factor that needs to be addressed whenever the particulates pollution is concerned. The size measurements were done with a cascade impactor of eight stages with a back-up filter. It effectively separates the particulate matter into nine-sizes ranging from 0.0-0.4 to 9.0-10.0 microm. Samples were analysed in nine-particle size fractions with special reference to a toxic metal - lead (Pb) by atomic absorption spectrophotometry (AAS). It was found that PM10 and Pb at both the intersections could easily be classified by the size distribution. The fractions of the PM10 and that of Pb showing a tendency of trimodal distributions with the first peak at coarse mode approximately 9.0-10.0 microm, second at approximately 5.8 microm and the third at coarse mode approximately1.1 microm. The significant percentage of Pb was found in the range below 2.5 microm at both the intersections. However, Pb in AQCR1 is found in the coarser range as well, which could probably be the influence of various industrial activities in the area. PM10 concentration values in the coarser range in AQCR2 are associated with the resuspension of dust particles and mechanical erosions.     

Reducing dust exposure in indoor climbing gyms

As users of indoor climbing gyms are exposed to high concentrations (PM(10) up to 4000 μg m(-3); PM(2.5) up to 500 μg m(-3)) of hydrated magnesium carbonate hydroxide (magnesia alba), reduction strategies have to be developed. In the present paper, the influence of the use of different kinds of magnesia alba on dust concentrations is investigated. Mass concentrations, number concentrations and size distributions of particles in indoor climbing gyms were determined with an optical particle counter, a synchronized, hybrid ambient real-time particulate monitor and an electrical aerosol spectrometer. PM(10) obtained with these three different techniques generally agreed within 25%. Seven different situations of magnesia alba usage were studied under controlled climbing activities. The use of a suspension of magnesia alba in ethanol (liquid chalk) leads to similar low mass concentrations as the prohibition of magnesia alba. Thus, liquid chalk appears to be a low-budget option to reduce dust concentrations. Magnesia alba pressed into blocks, used as powder or sieved to 2-4 mm diameter, does not lead to significant reduction of the dust concentrations. The same is true for chalk balls (powder enclosed in a sack of porous mesh material). The promotion of this kind of magnesia alba as a means of exposure reduction (as seen in many climbing gyms) is not supported by our results. Particle number concentrations are not influenced by the different kinds of magnesia alba used. The particle size distributions show that the use of magnesia alba predominantly leads to emission of particles with diameters above 1 μm.     

Field comparison of three inhalable samplers (IOM, PGP-GSP 3.5 and Button) for welding fumes

Inhalable sampler efficiency depends on the aerodynamic size of the airborne particles to be sampled and the wind speed. The aim of this study was to compare the behaviour of three personal inhalable samplers for welding fumes generated by Manual Metal Arc (MMA) and Metal Active Gas (MAG) processes. The selected samplers were the ones available in Spain when the study began: IOM, PGP-GSP 3.5 (GSP) and Button. Sampling was carried out in a welding training center that provided a homogeneous workplace environment. The static sampling assembly used allowed the placement of 12 samplers and 2 cascade impactors simultaneously. 183 samples were collected throughout 2009 and 2010. The range of welding fumes' mass concentrations was from 2 mg m(-3) to 5 mg m(-3). The pooled variation coefficients for the three inhalable samplers were less than or equal to 3.0%. Welding particle size distribution was characterized by a bimodal log-normal distribution, with MMADs of 0.7 μm and 8.2 μm. For these welding aerosols, the Button and the GSP samplers showed a similar performance (P = 0.598). The mean mass concentration ratio was 1.00 ± 0.01. The IOM sampler showed a different performance (P < 0.001). The mean mass concentration ratios were 0.90 ± 0.01 for Button/IOM and 0.92 ± 0.02 for GSP/IOM. This information is useful to consider the measurements accomplished by the IOM, GSP or Button samplers together, in order to assess the exposure at workplaces over time or to study exposure levels in a specific industrial activity, as welding operations.     

Chemical composition, sources, solubility, and transport of aerosol trace elements in a tropical region

Aerosol particle samples (PM10) were collected at urban, industrial and rural sites located in Rio de Janeiro, Brazil, between October 2008 and September 2009. Aerosol samples for each site were analyzed for total and soluble metals, water-soluble ions, carboxylic acids, and water-soluble organic carbon (WSOC). The results showed that the mean PM10 concentrations were 34 μg m(-3); 47 μg m(-3) and 71 μg m(-3) at the rural, urban and industrial sites, respectively. An increase in the average concentration of these particles due to air stagnation was observed during the period from May to September for all sites, and an increase in hospitalization for respiratory problems was also reported. On average, the anions species represented 4 to 14% of total content, while cations species corresponded to 1 to 11% and 7.5% for WSOC. The overall metal content at the industrial site was nearly the double that at the rural site. The concentrations of the studied species are influenced mainly by site location and the specific characteristics present at each site. However, higher concentrations of some species were observed on particular dates and were probably due to biomass burning and African dust events. The acid/aqueous percentiles showed that the most efficiently extracted metals from the aqueous phase were V and Ni (40%), while Al and Fe represented a lower percentage (<3%). Analysis of the aqueous fraction provides important information about the bioavailability of metals that is associated with the inflammatory process in the lungs.     

Chemical compositions and sources of atmospheric PM10 in heating, non-heating and sand periods at a coal-based city in northeastern China

Mass concentrations and chemical components (18 elements, 9 ions, organic carbon [OC] and elemental carbon [EC]) in atmospheric PM(10) were measured at five sites in Fushun during heating, non-heating and sand periods in 2006-2007. PM(10) mass concentrations varied from 62.0 to 226.3 μg m(-3), with 21% of the total samples' mass concentrations exceeding the Chinese national secondary standard value of 150 μg m(-3), mainly concentrated in heating and sand periods. Crustal elements, trace elements, water-soluble ions, OC and EC represented 20-47%, 2-9%, 13-34%, 15-34% and 13-25% of the particulate matter mass concentrations, respectively. OC and crustal elements exhibited the highest mass percentages, at 27-34% and 30-47% during heating and sand period. Local agricultural residuals burning may contribute to EC and ion concentrations, as shown by ion temporal variation and OC and EC correlation analysis. Heavy metals (Cr, Ni, Zn, Cu and Mn) from coal combustion and industrial processes should be paid attention to in heating and sand periods. The anion/cation ratios exhibited their highest values for the background site with the influence of stationary sources on its upper wind direction during the sand period. Secondary organic carbon were 1.6-21.7, 1.5-23.0, 0.4-17.0, 0.2-33.0 and 0.2-21.1 μg m(-3), accounting for 20-77%, 44-88%, 4-77%, 8-69% and 4-73% of OC for the five sampling sites ZQ, DZ, XH, WH and SK, respectively. From the temporal and spatial variation analysis of major species, coal combustion, agricultural residual burning and industrial emission including dust re-suspended from raw material storage piles were important sources for atmospheric PM(10) in Fushun at heating, non-heating and sand periods, respectively. It was confirmed by principal component analysis that coal combustion, vehicle emission, industrial activities, soil dust, cement and construction dust and biomass burning were the main sources for PM(10) in this coal-based city.     

Chemical composition and physical features of summer aerosol at Terra Nova Bay and Dome C, Antarctica

During the 2002-2003 austral summer field season, aerosol samples were collected at a coastal (Terra Nova Bay--Northern Victoria Land) and an inland site (Dome C--East Antarctic Plateau). The sampling was carried out by stacked filter units made up of two filters at different porosity (5.0 and 0.4 microm at Terra Nova Bay and 3.0 and 0.4 microm at Dome C), able to roughly separate a coarse from a fine fraction. At Dome C, a further investigation on aerosol size distribution was performed by an inertial impactor able to collect aerosol particles on 8 size classes (from 10 to 0.4 microm). Atomic Force Microscopy was applied to the filter collecting the finer fraction in both sites in order to assess the real cut-off value of the filter sandwich apparatus and to reconstruct the volume size distribution. At the employed flow conditions, the real cut-off value was revealed to be about one third with respect to the filter nominal porosity in both stations. The size distribution plots showed a bimodal distribution with a mode centered around 0.22 microm in both the sites and a second broader mode which is centered between 0.3 microm and 1.2 microm diameter at Terra Nova Bay and shifted toward higher values (centred around 1.0 microm diameter) at Dome C. Each filter was analysed for the main and trace ionic components allowing evaluation of the contributions of primary and secondary aerosol sources at the two sites as a function of the particle size class. The coastal site is mainly affected by primary and secondary marine inputs: the sea spray contribution (Na+, Mg2+, Cl- and ssSO4(2-)) is dominant (77% w/w) in the coarse fraction whereas the biogenic source (methanesulfonate and nssSO4(2-)) prevails (67.5% w/w) in the fine fraction. In this fraction a significant contribution (15.5% w/w) is provided by ammonium likely to be related to surrounding penguin colonies. Dome C atmosphere is characterised by fine particles arising from secondary sources and long-range transport processes. The main component in the fine and coarse fractions at Dome C is sulfate whose nssSO4(2-) represents the 99.5% and the 92.3%(w/w) in fine and coarse fraction, respectively. The observed agreement between nssSO4(2-) and methanesulfonate temporal profiles in the fine fraction demonstrates that biogenic emissions dominate the inland background aerosol. Results from the sampling by the 8-stage impactor at Dome C are presented here: chloride and nitrate are mainly deposited on the 10-2.1 microm stages while the highest sulfate concentration was found in the submicrometric fraction which turned out to be the most acidic. Such a distribution is able to prevent nitrate and chloride re-emission as gaseous HCl and HNO3 in the 10-2.1 microm stages, arising from the exchange reaction between chloride and nitrate salts and sulfuric acid. Moreover, the concentration peak observed for nitrate in coarser fractions is probably related also to the formation of hygroscopic NH4NO3 particles and nitrate adsorption on sea salt particles.     

Levels and chemical composition of PM in a city near a large Cu-smelter in Spain

A long-term series (2001-2008) of chemical analysis of atmospheric particulate matter (PM(10) and PM(2.5)) collected in the city of Huelva (SW Spain) is considered in this study. The impact of emission plumes from one of the largest Cu-smelters in the world on air quality in the city of Huelva is evidenced by the high daily and hourly levels of As, other potentially toxic elements (e.g. Cu, Zn, Cd, Se, Bi, and Pb) in particulate matter, as well as the high levels of some gaseous pollutants (NO(2) and SO(2)). Mean arsenic levels in the PM10 fraction were higher than the target value set by European Directive 2004/107/EC (6 ngAs m(-3)) for 1(st) January 2013. Hourly peak concentrations of As and other metals and elements (Zn, Cu, P and Se) analyzed by PIXE can reach maximum hourly levels as high as 326 ngAs m(-3), 506 ngZn m(-3), 345 ngCu m(-3), 778 ngP m(-3) and 12 ngSe m(-3). The contribution of Cu-smelter emissions to ambient PM is quantified on an annual basis in 2.0-6.7 μg m(-3) and 1.8-4.2 μg m(-3) for PM(10) and PM(2.5), respectively. High resolution outputs of the HYSPLIT dispersion model show the geographical distribution of the As ambient levels into the emission plume, suggesting that the working regime of the Cu-smelter factory and the sea breeze circulation are the main factors controlling the impact of the Cu-smelter on the air quality of the city. The results of this work improve our understanding of the behaviour of industrial emission plumes and their impact on air quality of a city, where the population might be exposed to very high ambient concentrations of toxic metals during a few hours.     

Cycling of rare earth elements in the atmosphere in central Tokyo

Concentrations of 14 rare earth elements (REEs) in six size classes of airborne particulate matter (APM) (<0.43, 0.43-0.65, 0.65-1.1, 1.1-2.1, 2.1-11, and >11 μm) and in two different phases (suspended particulate and dissolved) in rainwater were determined by inductively coupled plasma mass spectrometry (ICP-MS). Positive Eu and Tb anomalies were observed in size-classified APM. These anomalies may be due to large emissions of Eu and Tb to the atmosphere resulting from the recent change in Japan from the use of cathode-ray tubes to plasma displays in television sets (Eu and Tb) and from the widespread use of magneto-optical disks (Tb). The light REEs were enriched in fine APM particles (diameter < 1.1 μm). Because compositions of La/Ce/Sm in fine APM (diameter < 1.1 μm) were similar to those in automobile catalyst, the light REE enrichment was attributed to automobile emissions. In contrast, the REE distribution pattern in the suspended particulate phase in rainwater was similar to that in coarse APM (diameter > 2.1 μm), and a positive Tb anomaly was observed, suggesting that coarse particles easily become trapped in rain droplets. A negative Eu anomaly was observed in the dissolved phase in rainwater, but not in APM or in the suspended particulate phase in rainwater. Unlike other REEs, Eu can exist as both bivalent and trivalent ions in nature, and Eu-selective dissolution from or adsorption onto the trapped particles of Eu might account for the negative anomaly. These results show that atmospheric REE cycling is affected by the physico-chemical properties of APM.     

Composition of heavy metals and airborne fibers in the indoor environment of a building during renovation

The renovation of a building will certainly affect the quality of air in the vicinity of where associated activities were undertaken, this includes the quality of air inside the building. Indoor air pollutants such as particulate matter, heavy metals, and fine fibers are likely to be emitted during renovation work. This study was conducted to determine the concentration of heavy metals, asbestos and suspended particulates in the Biology Building, at the Universiti Kebangsaan, Malaysia (UKM). Renovation activities were carried out widely in the laboratories which were located in this building. A low-volume sampler was used to collect suspended particulate matter of a diameter size less than 10 μm (PM??) and an air sampling pump, fitted with a cellulose ester membrane filter, were used for asbestos sampling. Dust was collected using a small brush and scope. The concentration of heavy metals was determined through the use of inductively coupled plasma-mass spectroscopy and the fibers were counted through a phase contrast microscope. The concentrations of PM?? recorded in the building during renovation action (ranging from 166 to 542 μg m?3) were higher than the value set by the Department of Safety and Health for respirable dust (150 μg m?3). Additionally, they were higher than the value of PM?? recorded in indoor environments from other studies. The composition of heavy metals in PM?? and indoor dust were found to be dominated by Zn and results also showed that the concentration of heavy metals in indoor dust and PM?? in this study was higher than levels recorded in other similar studies. The asbestos concentration was 0.0038 ± 0.0011 fibers/cc. This was lower than the value set by the Malaysian Department of Occupational, Safety and Health (DOSH) regulations of 0.1 fibers/cc, but higher than the background value usually recorded in indoor environments. This study strongly suggests that renovation issues need to be considered seriously by relevant stakeholders within the university in order to ensure that the associated risks toward humans and indoor environment are eliminated, or where this is not feasible, minimized as far as possible.