Eduard Stelcer

Multielemental analysis and characterization of fine aerosols at several key ACE‐Asia sites

loadings of 29, 16, and 9.1 mg/m 3 and coarse mass loadings of 33, 14, and 11 mg/m 3 were measured at Hong Kong, Cheju, and Sado Island sites, respectively, during the study period. The corresponding maximum PM2.5 and coarse mass values for the three sites were 109, 81, and 78 mg/m 3 and 101, 162, and 253 mg/m 3 , respectively. Accelerator-based ion beam analysis (IBA) techniques were used to quantify major components as well as significant trace elements. These included total hydrogen, black carbon, F, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, and Pb, with detection limits close to or below 1 ng/m 3 . The average PM2.5 percentage composition by weight across the three sites was estimated to be around (8.4 ± 4)% black carbon, (7.7 ± 7)% soil, (43 ± 14)% ammonium sulfate, (11 ± 16)% organic matter, (10 ± 12)% salinity, and (0.6 ± 0.3)% trace elements. Soil fingerprints for the east Asian region were generated using oxides of measured Al, Si, K, Ca, Ti, Mn, and Fe concentrations. The coarse fraction was dominated by wind blown soil (23%) and sea salts (48%). [PM10/PM2.5] mass ratios were typically (2.1 ± 0.4) averaged across all sites for the whole year. [PM10/PM2.5] mass ratios for the 21 IBA elements analyzed were also provided. This quantitative data providing both masses and dates over an 18-month period provide useful input for aerosol transport modeling for the east Asia region. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0399 Atmospheric Composition and Structure: General or miscellaneous; 1610 Global Change: Atmosphere (0315, 0325); 1620 Global Change: Climate dynamics (3309); KEYWORDS: PM2.5, PM10, aerosols, fine particle characterization, Asian region, ACE-Asia, IBA techniques

Fine particle characterisation, source apportionment and long-range dust transport into the Sydney Basin: a long term study between 1998 and 2009

Ion beam analysis techniques have been used to characterise fine particle (PM2.5) pollution in the Sydney Basin between 1 July 1998 and 31 December 2009. Nearly 1 200 filters were obtained and analysed for more than 21 different chemical species from hydrogen to lead. Positive matrix factorisation was then applied to this significant database to determine 7 different source fingerprints and their contributions to the total PM2.5 mass. Most of these sources originated in the Sydney Basin, however there were significant windblown soil sources that originated not just from desert regions in central Australia but also from large agricultural regions around 500 km south west of the Basin. This long range transport of fine dust was tracked using hourly back trajectories for every sampling day during the study period and showed that 33% of extreme dust events were probably originating from agricultural regions and not the central desert regions of Australia as first thought.

Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia

The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings.

Size-resolved chemical composition of Australian dust aerosol during winter

Environmental context Mineral dust aerosol is both an efficient scatterer of solar radiation, potentially cooling the planet, and a moderate absorber, potentially warming it: the exact balance is both uncertain, and geographically variable. Australian desert soils are noticeably more reddish than most Northern Hemisphere deserts, most probably a result of enhanced iron mineralogy. This paper contains results from a field campaign designed to increase our understanding of the chemistry of Australian mineral dust aerosol, especially in relation to iron and salt. Abstract Australia is the dominant source of mineral dust aerosol in the Southern Hemisphere, yet the physical, chemical and optical properties of this aerosol remain poorly understood. Four sets of size-resolved aerosol samples were collected at a site on the edge of the Lake Eyre Basin (LEB), in the south-east dust transport pathway. Back trajectory analysis shows that three samples were sourced from the LEB (one during a rare winter dust storm), and one from coastal regions to the south. All samples were subjected to both ion beam analysis and ion chromatography. A Fe/Al ratio of 0.9 was found, consistent with results from our other campaigns to sites in the LEB, significantly higher than typical Northern Hemisphere values (~0.45–0.6). This confirms the iron-rich character of central Australian soils. Clear evidence of marine advection in the fourth sample was also found, and evidence of chloride depletion by nitric acid in two samples.

Source apportionment of PM2.5 at two receptor sites in Brisbane, Australia

Environmental context Fine particles affect air quality locally, regionally and globally. Determining the sources of fine particle is therefore critical for developing strategies to reduce their adverse effects. Advanced data analysis techniques were used to determine the sources of fine particles at two sites, providing information for future pollution reduction strategies not only at the study sites but in other areas of the world as well. Abstract In this study, samples of particulate matter with aerodynamic diameter less than 2.5 µm (PM2.5) collected at two sites in the south-east Queensland region, a suburban (Rocklea) and a roadside site (South Brisbane), were analysed for H, Na, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Pb and black carbon (BC). Samples were collected during 2007–10 at the Rocklea site and 2009–10 at the South Brisbane site. The receptor model Positive Matrix Factorisation was used to analyse the samples. The sources identified included secondary sulfate, motor vehicles, soil, sea salt and biomass burning. Conditional probability function analysis was used to determine the most likely directions of the sources. Future air quality control strategies may focus on the particular sources identified in the analysis.

Estimating the near-surface daily fine aerosol load using hourly Radon-222 observations

We investigate the extent to which hourly radon observations can be used to estimate daily PM2.5 loading near the ground. We formulate, test and apply a model that expresses the mean daily PM2.5 load as a linear combination of observed radon concentrations and differences on a given day. The model was developed using two consecutive years of observations (2007–2008) at four sites near Sydney, Australia, instrumented with aerosol samplers and radon detectors. Model performance was subsequently evaluated against observations in 2009. After successfully reproducing mean daily radon concentrations (r2≥0.98), we used the model to estimate daily PM2.5 mass, as well as that of selected elements (Si, K, Fe, Zn, H, S and Black Carbon). When parameterizing the model for elemental mass estimates the highest r2 values were generally obtained for H, BC, K and Si. Separating results by season, the r2 values for K and BC were higher in winter for all sites, a period of time where higher concentrations of these elements are seen and a rapid estimation tool would be of particular benefit. The best overall results were obtained in winter for H and BC [r2 = 0.50, 0.68, 0.70, 0.63 (H) and 0.57, 0.57, 0.78, 0.44 (BC)], respectively for Warrawong, Lucas Heights, Richmond and Muswellbrook. Evaluation of model PM2.5 estimates was most successful for days with typical aerosol loads; loads were usually underestimated for, the less frequent, high–to–extreme pollution days. The best elemental results were obtained for BC at Richmond in winter (r2 = 0.68). However, for Warrawong and Lucas Heights r2 values increased from 0.26 to 0.60, and from 0.33 to 0.73, respectively, when several particularly high concentration events were excluded from the analysis. The model performed best at Richmond, an inland site with relatively flat terrain. However, model parameters need to be evaluated for each site.

Heavy metal pathways and archives in biological tissue

Nuclear milli and microprobes at the Australian Nuclear Science and Technology Organisation (ANSTO) were used to determine lead accumulation in native Australian plants and animals. Three species of eucalypt plants (Eucalyptus camaldulensis, Eucalyptus globulus and Eucalyptus lesouefii), one species of salt bush (Atriplex burbhanyana) and one species each of acacia (Acacia saligna) and estuarine crocodiles (Crocodylus porosus) were investigated. Experimentally grown plants were subjected to a nutrient solution with a pH of 5 and spiked with a 200 μmol concentration of Pb. Lead concentrations in leaves of both E. globulus and E. camaldulensis showed an almost exponential decrease from the base of the main vein to the tip. Similarly, Pb concentrations decreased from the main vein to secondary veins. Concentrations of essential elements such as K, Fe, Zn and Br in the main and secondary veins were constant within experimental uncertainty. In contrast, the concentrations of Pb in the leaf veins of E. lesouefii were much lower and showed no systematic pattern. In stem and root samples the highest concentration of Pb was found in roots and stem of E. globulus and A. burbhanyana followed by E. camaldulensis. Some Pb was found in roots of A. saligna and only very low concentration in stem of the same plant. More detailed analysis of thin cross-sectional samples of roots and stem showed that Pb is present in much higher concentration in the growth area of the plant structure (i.e. meristemic region) and in relatively low concentration within the pith region and outer cortex. The osteoderms (dermal bones) of estuarine crocodiles, exposed to lead ammunition in food from the hunting activities of traditional Aboriginal owners, were sampled at two sites in Kakadu National Park, northern Australia. PIXE analyses showed enhanced, but relatively constant, ratios of Pb/Ca in the annual laminations. This was consistent with both their history of long term exposure to elevated anthropogenic Pb sources and the hypothesis that the osteoderm can be used as an archive of the crocodiles exposure to Pb during its life.

Proton induced X-ray emission and proton induced gamma ray emission analysis in geochemical exploration for gold and base metal deposits

Abstract Proton induced X-ray emission (PIXE) and proton induced gamma ray emission (PIGME) analysis has been used in geochemical exploration to determine various elements in rocks and regolith in relation to gold and base metal mineralisation. Elements analysed by PIXE include K, Fe, Ca, Ti, Mn, Cl, Ga, Rb, Sr, Zr, Y, Nb, Cu, Zn, Pb, Ni, As, V and Mo, and those by PIGME are Al, Na, Mg, F and Li. One of our research areas is Cobar, northwest of New South Wales, Australia. The study areas include the McKinnons and Peak gold deposits, the Wagga Tank base metal deposit and Lower Tank prospect, northeast of the CSA mine. Au, Cu, Zn, Pb, As and Ni are elevated as ore indicators near and around the ore deposits while K, Al, Ca, Na, Ti, Rb, Sr, Ga and V are depleted due to feldspar and mica destruction during alteration.

Reducing mortality risk by targeting specific air pollution sources: Suva, Fiji

Health implications of air pollution vary dependent upon pollutant sources. This work determines the value, in terms of reduced mortality, of reducing ambient particulate matter (PM2.5: effective aerodynamic diameter 2.5μm or less) concentration due to different emission sources. Suva, a Pacific Island city with substantial input from combustion sources, is used as a case-study. Elemental concentration was determined, by ion beam analysis, for PM2.5 samples from Suva, spanning one year. Sources of PM2.5 have been quantified by positive matrix factorisation. A review of recent literature has been carried out to delineate the mortality risk associated with these sources. Risk factors have then been applied for Suva, to calculate the possible mortality reduction that may be achieved through reduction in pollutant levels. Higher risk ratios for black carbon and sulphur resulted in mortality predictions for PM2.5 from fossil fuel combustion, road vehicle emissions and waste burning that surpass predictions for these sources based on health risk of PM2.5 mass alone. Predicted mortality for Suva from fossil fuel smoke exceeds the national toll from road accidents in Fiji. The greatest benefit for Suva, in terms of reduced mortality, is likely to be accomplished by reducing emissions from fossil fuel combustion (diesel), vehicles and waste burning.

Hydrogen Measurements in SiNx: H/Si Thin Films by ERDA

Thin SiN film deposited on Si by plasma enhanced chemical vapour deposition (PECVD) is used for surface passivation of Si. During the PECVD process Hydrogen is incorporated into the SiN film, and the passivation properties of the resulting SiNx:H layers play an important role in enhancing the energy conversion efficiency of solar cells. It is believed that the Hydrogen present in SiNx:H is responsible for this enhancement, and therefore its concentration in the passivating layer is an important parameter. The Hydrogen composition and its depth profile in thin SiNx:H films of 20nm to 200nm was measured by elastic recoil detection analysis (ERDA), using a 1.7MeV He+ ion beam of (1x2)mm2, generated by a high stability 2MV Tandetron ion beam accelerator. Simultaneously, Rutherford backscattering (RBS) spectra were recorded for each sample. The results show that the Hydrogen concentration in the SiNx:H layers is dependent of the deposition conditions. Also, Hydrogen was found to be homogenously distributed across the SiNx:H layer thickness, and the SiNx:H/Si interfaces were well defined.