Atmospheric Environment (v.35, #15)

The measurements of C2–C9 volatile organic compounds (VOC) were carried out at a site in Seoul, the capital of Korea from August 1998 to July 1999. Air samples were collected for 24 h in 6 l SUMMA canisters every 6 days. The canister samples were quantitatively analyzed by a GC/FID and GC/MS. The species with the highest mean concentration among the 70 identified was propane (7.8 ppb), followed by toluene (6.4 ppb) and ethylene (5.9 ppb). The high concentration of propane was mainly attributed to the emissions by liquefied petroleum gas (LPG) usage for cooking and heating, and butane fuel for transportation. The general trend of the seasonal variation shows higher concentrations in winter and lower ones in summer. This behavior was mainly caused by the variations of temperature, and resultant VOC source strengths, coupled with the variations of the mixing depth. According to the analysis of concentration ratios, the seasonal contributions of the major emission sources to the VOC concentrations were influenced by ambient temperature. Further, it was identified that the contributions by the use of solvents, natural gas, LPG, and butane fuel were closely related to the variations of consumption pattern according to seasons. Through the analysis of the concentration correlations between less reactive compound and highly reactive ones for summer and winter months, it was found that photochemical reactivity affects relative concentration of reactive compound.
Keywords: C2–C9 seasonal concentrations; Emission sources; Temperature; Amount used; Photochemical reactivity;

Determining the sources of atmospheric particles in Shanghai, China, from magnetic and geochemical properties by Jiong Shu; John A Dearing; Andrew P Morse; Lizhong Yu; Nu Yuan (2615-2625).
The study describes an investigation into the sources of atmospheric particles collected at 11 sites across Shanghai, China, during one week in November 1998. Source ascription is based on mineral magnetic and geochemical properties, and a chemical mass balance (CMB) model. The CMB model shows that the main contributions to total suspended particles (TSPs) are products of coal combustion, with lesser contributions from construction sites, vehicle emissions, windblown soil and steel-making furnaces. The spatial variability of concentration-dependent magnetic parameters and heavy metal concentrations support the findings from the CMB model. In general, the variability of magnetic quotient parameters is lower than for concentration parameters. This suggests that there are relatively constant proportions of low coercivity ‘magnetite’ and high coercivity ‘haematite’ mineral phases in dust samples at all sites, with a dominance of superparamagnetic (SP) and multidomain (MD)+pseudo-single domain (PSD) ‘magnetite’ grains. MD+PSD grains are produced to a large extent by fossil-fuel combustion emissions, particularly from the main iron and steel manufacturing and power generation industrial complex. Linear multiple regression analyses show that some non-destructive and rapid magnetic measurements may be used to estimate the concentrations of common heavy metals in TSPs.
Keywords: Atmospheric pollution; Environment magnetism; Chemical mass balance; Total suspended particles; Shanghai;

Concentrations and distributions of elemental carbon (EC) and organic carbon (OC) in particles were measured in Kaohsiung City, Taiwan. PM10 and PM2.5 samples were collected using a dichotomous sampler from November 1998 to April 1999 and were analyzed for carbonaceous species with an elemental analyzer. The concentrations of carbonaceous species in Kaohsiung City were comparable to those at other urban locations in the world. On average, carbonaceous species accounted for 21.2% of the PM2.5 and 18.1% of the PM10. It was found that organic carbon dominated the carbonaceous species and was 72.2 and 70.4% of total carbon (TC) for PM2.5 and PM10. The secondary organic carbon formed through the volatile organic compound gas-to-particle conversion was estimated from the minimum ratio between elemental and organic carbon obtained in this study, and was found to constitute 40.0 and 32.4% of the total organic carbon particle for PM2.5 and PM10 (or 6.6 and 4.5% of the total particle mass).
Keywords: Particulate matter; Carbonaceous species; OC–EC ratio; Secondary organic carbon;

Vehicle exhaust is a major source of air pollution in metropolitan cities. Commuters are exposed to high traffic-related pollutant concentrations. Public transportation is the most popular commuting mode in Hong Kong and there are about 10.8 million passenger trips every day. Two-thirds of them are road commuters. An extensive survey was conducted to measure carbon monoxide in three popular passenger commuting modes, bus, minibus, and taxi, which served, respectively, 3.91 million, 1.76 million and 1.31 million passenger trips per day in 1998. Three types of commuting microenvironments were selected: urban–urban, urban–suburban and urban–rural. Results indicated that in-vehicle CO level increased in the following order: bus, minibus and taxi. The overall average in-vehicle CO level in air-conditioned bus, minibus and taxi were 1.8, 2.9 and 3.3 ppm, respectively. The average concentration level difference between air-conditioned buses (1.8 ppm) and non-air-conditioned buses (1.9 ppm) was insignificant. The fluctuation of in-vehicle CO level of non-air-conditioned vehicle followed the variation of out-vehicle CO concentration. Our result also showed that even in air-conditioned vehicles, the in-vehicle CO concentration was affected by the out-vehicle CO concentration although there exists a smoothing out effect. The in-vehicle CO level was the highest in urban–suburban commuting routes and was followed by urban–urban routes. The in-vehicle CO level in urban–rural routes was the lowest. The highest CO level was recorded after the vehicle traversed through tunnel. The average CO exposure of a commuter in tunnel can be 2–3 times higher than that at the other roads. The CO exposure level of public road transportation commuters in Hong Kong was lower than most other cities. Factors governing the CO levels were also discussed.
Keywords: Public transportation; Microenvironment; Carbon monoxide; Human exposure;

Sulphate aerosol size distributions at Mumbai, India, during the INDOEX-FFP (1998) by Chandra Venkataraman; Prashant Sinha; Sachin Bammi (2647-2655).
Sulphate size distributions were measured at the coastal station of Mumbai (formerly Bombay) through 1998, during the Indian ocean experiment (INDOEX) first field phase (FFP), to fill current gaps in size-resolved aerosol chemical composition data. The paper examines meteorological, seasonal and source-contribution effects on sulphate aerosol and discusses potential effects of sulphate on regional climate. Sulphate size-distributions were largely trimodal with a condensation mode (mass median aerodynamic diameter or MMAD 0.6 μm), a droplet mode (MMAD 1.9–2.4 μm) and a coarse mode (MMAD 5 μm). Condensation mode sulphate mass-fractions were highest in winter, consistent with the high meteorological potential for gas-to-particle conversion along with low relative humidity (RH). The droplet mode concentrations and MMADs were larger in the pre-monsoon and winter than in monsoon, implying sulphate predominance in larger sized particles within this mode. In these seasons the high RH, and consequently greater aerosol water in the droplet mode, would favour aerosol-phase partitioning and reactions of SO2. Coarse mode sulphate concentrations were lowest in the monsoon, when continental contribution to sulphate was low and washout was efficient. In winter and pre-monsoon, coarse mode sulphate concentrations were somewhat higher, likely from SO2 gas-to-particle conversion. Low daytime sulphate concentrations with a large coarse fraction, along with largely onshore winds, indicated marine aerosol predominance. High nighttime sulphate concentrations and a coincident large fine fraction indicated contributions from anthropogenic/industrial sources or from gas-to-particle conversion. Monthly mean sulphate concentrations increased with increasing SO2 concentrations, RH and easterly wind direction, indicating the importance of gas-to-particle conversion and industrial sources located to the east. Atmospheric chemistry effects on sulphate size distributions in Mumbai, indicated by this data, must be further examined.
Keywords: Sources; Seasonal variation; Urban/coastal site; Indian ocean experiment; Regional climate;

Tropical tropospheric ozone observed in Thailand by Pakpong Pochanart; Jiemjai Kreasuwun; Phaka Sukasem; Werathep Geeratithadaniyom; Monthip S Tabucanon; Jun Hirokawa; Yoshizumi Kajii; Hajime Akimoto (2657-2668).
The mixing ratios of surface ozone at two rural/remote sites in Thailand, Inthanon and Srinakarin, have been measured continuously for the first time. Almost identical seasonal variations of O3 with dry season maximum and a wet season minimum with a large seasonal amplitude are observed at both sites during 1996–1998. At Inthanon, the monthly averaged O3 mixing ratios range 9–55 ppb, with the annual average of 27 ppb. The ozone mixing ratios at Srinakarin are in the similar range, 9–45 ppb with annual average of 28 ppb. Based on trajectory analysis of O3 data at Inthanon, the long-range transport of O3 under Asian monsoon regime could primarily explain the low O3 mixing ratios of 13 ppb in clean marine air mass from Indian Ocean during wet season but only partly explain the relatively low O3 mixing ratios, 26 ppb or less, in continental air mass from northeast Asia either in wet or dry season. The highest O3 mixing ratios are found in air masses transported within southeast Asia, averaged 46 ppb in dry season. The high O3 mixing ratios during the dry season are suggested to be significantly due to the local/sub-regional scale O3 production triggered by biomass burning in southeast Asia rather than long-range transport effect.
Keywords: Biomass burning; Regional source; Southeast Asia; Trajectory analysis; Long-range transport;

Comparative receptor modelling study of TSP, PM2 and PM2−10 in Ho Chi Minh City by P.D. Hien; N.T. Binh; Y. Truong; N.T. Ngo; L.N. Sieu (2669-2678).
Elemental compositions were measured for TSP (total suspended particulate matter), PM2−10 and PM2 (particulate matter with aerodynamic diameters from 2 to 10 μm and less than 2 μm, respectively) in Ho Chi Minh City. Concentrations of 23 elements and particulate mass (PM) were used for receptor modelling to identify and quantify aerosol sources using principal component factor analysis (PCFA). A suite of factors containing similar elements with significant factor loadings were revealed among the factor matrices, thus facilitating the identification of common sources for different aerosol types. These sources include vehicular emissions (Br and Zn), coal burning (Se), industrial processes (Ce, Co, Cr, Pb and Sb), road dust (Al, Ti, V), soil dust (Fe and Th) and biomass burning (K). Marine aerosols (Na and Cl) and mineral fly ash (Sc and La) were revealed only in the PM2−10 model. For TSP, the last four sources are combined in one factor. The last (9th) factor in the PM2 model, characterised by a high loading from PM and insignificant loadings from elements, was attributed to secondary sulphates and organics, although these constituents were not measured in the experiments. Such a remarkable source identification capability of the modelling technique highlights the significance of achieving an optimal factor solution as a crucial step in PCFA, that was done by systematically varying the number of factors retained and carefully evaluating each factor matrix for both model fitting performance and physical reasonableness.
Keywords: INAA; Receptor modelling; Optimal number of factors; Source fingerprints; Sources of unmeasured species;

Regional and sectoral assessment of greenhouse gas emissions in India by Amit Garg; Sumana Bhattacharya; P.R Shukla; V.K Dadhwal (2679-2695).
In this paper the authors have estimated for 1990 and 1995 the inventory of greenhouse gases CO2, CH4 and N2O for India at a national and sub-regional district level. The district level estimates are important for improving the national inventories as well as for developing sound mitigation strategies at manageable smaller scales. Our estimates indicate that the total CO2, CH4 and N2O emissions from India were 592.5, 17, 0.2 and 778, 18, 0.3 Tg in 1990 and 1995, respectively. The compounded annual growth rate (CAGR) of these gases over this period were 6.3, 1.2 and 3.3%, respectively. The districts have been ranked according to their order of emissions and the relatively large emitters are termed as hotspots. A direct correlation between coal consumption and districts with high CO2 emission was observed. CO2 emission from the largest 10% emitters increased by 8.1% in 1995 with respect to 1990 and emissions from rest of the districts decreased over the same period, thereby indicating a skewed primary energy consumption pattern for the country. Livestock followed by rice cultivation were the dominant CH4 emitting sources. The waste sector though a large CH4 emitter in the developed countries, only contributed about 10% the total CH4 emission from all sources as most of the waste generated in India is allowed to decompose aerobically. N2O emissions from the use of nitrogen fertilizer were maximum in both the years (more than 60% of the total N2O). High emission intensities, in terms of CO2 equivalent, are in districts of Gangetic plains, delta areas, and the southern part of the country. These overlap with districts with large coal mines, mega power plants, intensive paddy cultivation and high fertilizer use. The study indicates that the 25 highest emitting districts account for more than 37% of all India CO2 equivalent GHG emissions. Electric power generation has emerged as the dominant source of GHG emissions, followed by emissions from steel and cement plants. It is therefore suggested, to target for GHG mitigation, the 40 largest coal-based thermal plants, five largest steel plants and 15 largest cement plants in India as the first step.
Keywords: Greenhouse gas (GHG); Carbon dioxide; Methane; Nitrous oxide; CO2 equivalent; Disaggregated emissions; Mitigation flexibility.;

The air quality modelling system Pollutants in the Atmosphere and their Transport over Hong Kong (PATH) has been designed to provide guidance on policy and emission controls in Hong Kong. One important air quality objective to be addressed is the annual-average concentration of respirable suspended particulates (RSP). In PATH, this is done by suitably weighting the simulation results from seven case-study days, each representative of a major meteorological category. This paper describes the selection of these categories, a procedure which follows Heywood (Technical Memoirs, Hong Kong Observatory, No. 6, 1953) and is based on the dominant meteorological mean sea-level pressure (MSLP) patterns for Hong Kong. A statistical analysis of RSP data from five sites showed that the chosen categories, while stratified by meteorology, are also valid for clustering the daily mean RSP concentrations into groups of similar days. The weighting coefficients (annual frequency) were obtained from an inspection of daily weather charts between 1990 and 1995. For each category, the actual day selected for modelling with PATH was chosen so that the daily-mean RSP value for each site was close to the mean for the category. In this way, the annual mean computed using the modelled days is little different from the observed annual mean at each site.
Keywords: Hong Kong; Respirable suspended particulates; Meteorological patterns; PATH; Annual average; Cluster analysis;

Characteristics of single particles sampled in Japan during the Asian dust–storm period by Chang-Jin Ma; Mikio Kasahara; Robert Höller; Tomihiro Kamiya (2707-2714).
To investigate the characteristics of Asian dust storm particles as single particles in Japan, we measured morphology, composition and concentration of single particles using Scanning Electron Microscope (SEM) coupled with an energy dispersive X-ray microanalyzer (EDX), particle induced X-ray emission (PIXE) and micro-PIXE. Particles were sampled in Kyoto, Japan from the middle of April to the end of July 1999. Mass concentration in Asian dust–storm events was roughly 3–5 times higher than that of the highest concentration measured in non-Asian dust storm seasons. Single particles were generally sharp-edged and irregular in shape and contained mostly crustal elements such as Si, Fe, Ca and Al. Particles which have more than 40% Si content comprised nearly 50% of coarse single particles in Asian dust storm events. Main concentration range of Al in single Asian dust storm particles was 10–20%, and those of Ca and Fe were below 10%. Even though S and Cl in soils of the desert and loess areas in northwest of China were not detected, significant concentration of S and Cl in coarse fraction in Asian dust storm event were detected in single particles. Especially, the maximum concentration of S in Asian dust storm event was about 5 times higher than that in non-Asian dust storm days. Every single particle in coarse fraction existed as the mixing state of soil components and S. Good agreement between the results of SEM–EDX analysis and that of micro-PIXE analysis was obtained in this study.
Keywords: Asian dust storm; Single particle; Long-range transport; Micro-PIXE; Mixing state;

Characteristic number size distribution of aerosol during Asian dust period in Korea by Youngsin Chun; Jiyoung Kim; Jae Cheon Choi; Kyung On Boo; Sung Nam Oh; Meehye Lee (2715-2721).
The size-separated number concentrations of aerosols ranging from 0.3 to 25 μm were observed in Seoul and Anmyon Island in the west coast of Korea during Asian dust period in Spring 1998. During the heavy dust period, the number size distributions of aerosols observed in both places were characterized by decreases in small size<0.5 μm and increase in large size between 1.35 and 10 μm. For particles in this range, there was a good correlation between number concentrations observed in both two places. The number of coarse particles >10 μm showed a distinct diurnal variation without a significant change in amplitude, which was more pronounced in Seoul. It suggests that coarse particles were more affected by local sources. Trajectories back in time showed that the air collected in Korea during dust period originated from desert regions in the central part of China. From these results, it was evident that increased particles in the range of 1.35–10 μm during dust source period represented mineral components, which originated possibly from the dust source regions.
Keywords: Aerosol; Mineral dust; Number concentration; Yellow sand; Long-range transport;

Investigating the haze transport from 1997 biomass burning in Southeast Asia: its impact upon Singapore by Lawrence C.C. Koe; Avelino F. Arellano; John L. McGregor (2723-2734).
The 1997 Indonesia forest fires was an environmental disaster of exceptional proportions. Such a disaster caused massive transboundary air pollution and indiscriminate destruction of biodiversity in the world. The immediate consequence of the fires was the production of large amounts of haze in the region, causing visibility and health problems within Southeast Asia. Furthermore, fires of these magnitudes are potential contributors to global warming and climate change due to the emission of large amounts of greenhouse gases and other pyrogenic products.The long-range transport of fire-related haze in the region is investigated using trajectories from the CSIRO Division of Atmospheric Research Limited Area Model (DARLAM). Emission scenarios were constructed for hotspot areas in Sumatra and Kalimantan for the months of September and October 1997 to determine the period and fire locations most critical to Singapore. This study also examines some transport issues raised from field observations. Results show that fires in the coastal areas of southeast Sumatra and southwest Kalimantan can be potential contributors to transboundary air pollution in Singapore. Singapore was directly affected by haze from these areas whereas Kuala Lumpur was heavily affected by the haze coming from Sumatra. In most cases, Singapore was more affected by fires from Kalimantan than was Kuala Lumpur. This was mainly a result of the shifting of monsoons. The transition of monsoons resulted in weaker low-level winds and shifted convergence zones near to the southeast of Peninsular Malaysia. In addition to severe drought and massive fire activity in 1997, the timing of the monsoon transition has a strong influence on haze transport in the region.
Keywords: Particulate matter; Southeast Asia biomass burning; Atmospheric transport; Modeling; Monsoon;

We present measurements of several trace gases made at a subtropical coastal site in Hong Kong in October and November 1997. The gases include O3, CO, SO2, and NOx. The surface measurement data are compared with those from an aircraft study [Kok et al. J. Geophys. Res. 102 (D15) (1997) 19043–19057], and a subset of the latter is used to show the vertical distribution of the trace gases in the boundary layer. During the study period, averaged concentrations at the surface site for O3, CO, NO x , and SO2 were 50, 298, 2.75, and 1.65 ppbv, respectively. Their atmospheric abundance and diurnal pattern are similar to those found in the “polluted” rural areas in North America. The measured trace gases are fairly well mixed in the coastal boundary layer in the warm South China region. Large variability is indicated from the data. Examination of 10-day, isentropic back trajectories shows that the measured trace gases are influenced by maritime air masses, outflow of pollution-laden continental air, and the mixing of the two. The trajectories capture the contrasting chemical features of the large-scale air masses impacting on the study area. CO, NO x and SO2 all show higher concentrations in the strong outflow of continental air, as expected, than those in the marine category. Compared with previously reported values for the western Pacific, the much higher levels found in the marine trajectories in our study suggest the impacts of regional and/or sub-regional emissions on the measured trace gases at the study site. The presence of abundant O3 and other chemically active trace gases in the autumn season, coupled with high solar radiation and warm weather, suggests that the South China Sea is a photochemically active region important for studying the chemical transformation of pollutants emitted from the Asian continent.
Keywords: Ozone; CO; NO x ; SO2; Coastal Hong Kong; Subtropical Asia;

Concentrations of volatile organic compounds in an industrial area of Korea by Kwangsam Na; Yong Pyo Kim; Kil-Choo Moon; Il Moon; Kochy Fung (2747-2756).
We measured and analyzed daily mean concentrations of volatile organic compounds (VOC) at Ulsan industrial and downtown sites from 3 to 8 June 1997. The industrial site is situated at the boundary of a petrochemical complex and the other is at downtown area in Ulsan. At each site, we collected ambient air samples in passivated stainless-steel containers by using constant flow samplers and analyzed them by a GC-FID. At Ulsan industrial site, the concentrations and their daily variations of total VOC were higher than those at the downtown site. The concentrations of oxygenated hydrocarbons were the highest among seven hydrocarbon groups at both sites. The fraction of C2–C5 light hydrocarbon concentrations to C2–C9 hydrocarbons at Ulsan industrial site was higher than that in other industrial areas. It suggests that fugitive emissions of light hydrocarbons in Ulsan industrial areas might be higher than those of other industrial areas. Under favorable wind conditions, the influence of industrial emissions of VOC on the downtown hydrocarbon levels was observed.
Keywords: City of Ulsan; Emission sources; Hazardous organics; Fugitive emissions;

PM10 and PM2.5 concentrations in Central and Eastern Europe: by Danny Houthuijs; Oscar Breugelmans; Gerard Hoek; Éva Vaskövi; Eva Miháliková; Jozef S. Pastuszka; Vitezslav Jirik; Stela Sachelarescu; Dobrinka Lolova; Kees Meliefste; Evtimia Uzunova; Carmen Marinescu; Jaroslav Volf; Frank de Leeuw; Henk van de Wiel; Tony Fletcher; Erik Lebret; Bert Brunekreef (2757-2771).
Between November 1995 and October 1996, particulate matter concentrations (PM10 and PM2.5) were measured in 25 study areas in six Central and Eastern European countries: Bulgaria, Czech Republic, Hungary, Poland, Romania and Slovak Republic. To assess annual mean concentration levels, 24-h averaged concentrations were measured every sixth day on a fixed urban background site using Harvard impactors with a 2.5 and 10 μm cut-point. The concentration of the coarse fraction of PM10 (PM10−2.5) was calculated as the difference between the PM10 and the PM2.5 concentration. Spatial variation within study areas was assessed by additional sampling on one or two urban background sites within each study area for two periods of 1 month. QA/QC procedures were implemented to ensure comparability of results between study areas. A two to threefold concentration range was found between study areas, ranging from an annual mean of 41 to 98 μg m−3 for PM10, from 29 to 68 μg m−3 for PM2.5 and from 12 to 40 μg m−3 for PM10−2.5. The lowest concentrations were found in the Slovak Republic, the highest concentrations in Bulgaria and Poland. The variation in PM10 and PM2.5 concentrations between study areas was about 4 times greater than the spatial variation within study areas suggesting that measurements at a single sampling site sufficiently characterise the exposure of the population in the study areas. PM10 concentrations increased considerably during the heating season, ranging from an average increase of 18 μg m−3 in the Slovak Republic to 45 μg m−3 in Poland. The increase of PM10 was mainly driven by increases in PM2.5; PM10−2.5 concentrations changed only marginally or even decreased. Overall, the results indicate high levels of particulate air pollution in Central and Eastern Europe with large changes between seasons, likely caused by local heating.
Keywords: Particulate matter; QA/QC; Central and Eastern Europe;

Regional air pollution caused by a simultaneous destruction of major industrial sources in a war zone. The case of April Serbia in 1999 by Zorka B. Vukmirović; Miroslava Unkašević; Lazar Lazić; Ivana Tošić (2773-2782).
During NATO's 78-day Kosovo war, 24 March–10 June 1999, almost daily attacks on major industrial sources have caused numerous industrial accidents in Serbia. These accidents resulted in releases of many hazardous chemical substances including the persistent organic pollutants (POPs). Detection of some important POPs in fine aerosol form took place at Xanthi in Greece and reported to the scientific world. The paper focuses on two pollution episodes: (a) 6–8 April; and (b) 18–20 April. Using the Eta model trajectory analysis, the regional pollutant transport from industrial sites in Northern Serbia (Novi Sad) and in the Belgrade vicinity (Pančevo), respectively, almost simultaneously bombed at midnight between 17 and 18 April, corroborated measurements at Xanthi. At the same time the pollutant puff was picked up at about 3000 m and transported to Bulgaria, Romania, Ukraine, Moldavia and the Black Sea. The low-level trajectories from Pančevo below 1000 m show pollutant transport towards Belgrade area in the first 12 h. The POP washout in central and southern Serbia in the second episode was deemed to have constituted the principal removal mechanism. Maximum POP wet deposition was found in central Serbia and along the 850 hPa trajectory towards south-eastern Serbia and the Bulgarian border.
Keywords: Accidental gas release; War-impact assessment; Particulate matter; Pollutant transport modelling; POP deposition;

Lead isotope ratios in the urban air of eastern and central Russia by Hitoshi Mukai; Toshinobu Machida; Atsushi Tanaka; Yelpatievskiy Pavel Vera; Mitsuo Uematsu (2783-2793).
In order to characterize airborne lead in eastern and central Russian cities in terms of lead isotope ratios, aerosol samples were collected at six selected cities and Moscow, and their lead concentrations and isotope ratios were studied by comparing them to the data of ore lead used in Russia. All eastern Russian cities (Vladivostok, Khabarovsk and Yakutsk) were found to have isotope ratios similar to those of ore leads in Kazakhstan, the major lead producer for Russia. Samples collected in Moscow also showed isotope ratios similar to those of eastern Russian cities. The contribution from coal combustion to airborne lead was considered to be small even in winter, in these cities. This observation suggested that the origin of lead in these Russian atmosphere regions is closely related to the lead products (e.g. leaded gasoline). The lead isotope ratios in three eastern Russian cities were very close to the value for Russian air mass reported previously in Japan, which were also in good agreement with the same observation in Sweden. However, considerably different lead isotope ratios were observed in central Russian cities, Kemerovo and Nizhnevartovsk, indicating that specific lead emissions, such as industrial activities using Precambrian-age ores or unique leaded gasoline, might contribute to the atmospheric lead.
Keywords: Lead isotope ratio; Russia; Aerosol; Lead ore; Transport;

Methane oxidation in Polish forest soils of contrasting atmospheric pollution by Søren Christensen; Anna Degórska; Anders Priemé (2795-2798).
Methane consumption was measured in forest soils of Poland in areas of high regional air pollution (SO2 loads) and compared to the activity in areas of low air pollution loads. The areas include the regions with the highest input of SO2 found in Europe and cover a range of average acid deposition up to a factor of 10. No distinct pattern of methane oxidation activities was identified that could be related to present or previous SO2 loads. Methane consumption activity ranged between 16 and 110 μg CH4  m−2  h−1 similar to the activity encountered in previous studies of forested areas.
Keywords: Acid deposition; SO2; Methane oxidizing bacteria;