The capital city of Mongolia, Ulaanbaatar, suffers from high levels of pollution due to excessive airborne particulate matter (APM). A lack of systematic data for the region has inspired investigation into the type, origin and seasonal variations of this pollution, the effects of meteorological conditions and even the time-dependence of anthropogenic sources. This work reports source apportionment results from a large data set of 184 samples each of fine (PM 2.5 ) and coarse (PM 2.5-10 ) fraction atmospheric PM collected over a three-year period (2014)(2015)(2016) in Ulaanbaatar, Mongolia. Positive Matrix Factorization (PMF) was applied using the concentrations of 16 elements measured by an energy dispersive X-ray fluorescence spectrometer along with the black carbon content measured by a reflectometer as input data. The PMF results revealed that whereas mixed sources dominate the coarse fraction, soil and traffic sources are the principle contributors to the fine fraction. The source profiles and the seasonal variations of their contributions indicate that fly ash emanating from coal combustion mixes with traffic emissions and resuspended soil, resulting in variable chemical source profiles. Four sources were identified for both fractions, namely, soil, coal combustion, traffic and oil combustion, which respectively contributed 35%, 16%, 41% and 8% to the coarse fraction and 31%, 27%, 31% and 11% to the fine fraction. Additionally, the probable source contributions from long-range transport events were assessed via concentration-weighted trajectory analysis.
Due to increased energy demands from its rapidly growing economy and population, ambient air in Ulaanbaatar, the capital city of Mongolia contains some of the highest reported air particulate matter (APM) concentrations in the world. The purpose of this study is to identify major APM sources. Source apportionment is an elegant and effective way to establish baseline data for mitigation strategies that focus on reducing APM pollution. The Nuclear Research Centre at the National University of Mongolia has been conducting APM pollution studies in Ulaanbaatar since 2004. Results presented here are based on a sampling campaign from June 2008 to May 2009 at two sites in Ulaanbaatar. APM samples were collected on polycarbonate filter, in two size fractions, fine (PM2.5) and coarse (PM10-2.5) particulate matter. Ion beam analysis provided the elemental concentration values and receptor modeling was used to determine the sources contributing to the particulate matter pollution. The results show that the main sources of PM pollution are soil, motor vehicles, coal and wood combustion, with varying contributing amounts at each site. Source contributions to PM2.5 at a residential site were found to be: soil 47%, coal combustion 35%, motor vehicles/road dust 13% and biomass burning 4%. At the residential site it was found that the primary source contributors to PM10-2.5 were soil 71%, coal combustion 10%, and motor vehicles/road dust 19%.Source contributions to PM2.5 at a non-residential site were found to be: coal combustion 92%, motor vehicles/road dust 3%, soil 3% and biomass burning 2%. At the non-residential site it was found that the primary source contributors to PM10-2.5 were: soil 92%, motor vehicle/road dust 5% and coal combustion 3%.
The elemental composition has been extensively used to characterize wine and to find correlations with environmental and winemaking factors. Although X-ray fluorescence (XRF) techniques offer many advantages, they have been rarely used for wine analysis. Here, we show the comparison of wine elemental composition results obtained by total reflection X-ray fluorescence (TXRF) and energy dispersive X-ray fluorescence (EDXRF) for elements K, Ca, Mn, Fe, Cu, Zn, Br, Rb, and Sr. The results obtained by TXRF and EDXRF have been additionally verified by inductively coupled plasma–mass spectrometry. The important analytical features of XRF techniques in wine science have been described, the preservation of volatile elements (e.g., Br) being one of their main advantages. In addition, we have shown that XRF techniques offer an optimal analytical approach for building large data sets containing highly reliable and reproducible results of elemental abundances in wines, corresponding soils, and grape juice. Such data sets are especially important for the geographic authentication of wine. This has been shown for 37 Austrian and Croatian wines collected together with respective soils from selected wine regions. The element abundances in soil reflect in a large portion in grape juice and finished wine suggesting that the contribution of the soil, that is, the plant uptake capacity expressed as c i(wine)/c i(soil) concentration factors, can be a highly discriminating factor for wine fingerprinting. This indeed has been proved in the present study in comparison to discrimination based only on wine element abundances. We have identified Fe, Zn, Br, Rb, and Sr as the best discriminator elements for the geographical authentication of wine. The study opens a new perspective in extending the application of XRF techniques as a cost-effective analytical tool for creating large databases of soil, grape juice, and wine element abundances for the evaluation of soil characteristics and other environmental parameters on wine composition.
This study presents chemical speciation results of atmospheric particulate matter (PM) samples from Ulaanbaatar, Mongolia. The health effect of atmospheric aerosol depends, among others, on their size distribution, elemental composition and contained chemical species which can be variable due to the nature of the contributing pollution sources and meteorological conditions at the sampling site. Samples of PM2.5 (fine) and PM10-2.5 (coarse) were measured by X-ray Absorption Near-edge Structure (XANES) spectroscopy under ultra-high vacuum environment with shallow angle synchrotron beam excitation at International Atomic Energy Agency (IAEA) experimental end-station installed at the XRF beamline of Elettra Sincrotrone Trieste, Italy. The XANES study was conducted across the K-edge of the transition metals chromium and zinc on selected fine and coarse PM samples. The selections were based on their high total Cr and Zn concentrations as determined by energy dispersive X-ray Fluorescence (EDXRF) analysis. XANES results revealed that the major chemical forms of Cr for both fine and coarse fractions are the chromium sulfate (Cr2(SO4)3) and chromium(III) oxide (Cr2O3) compounds. Concerning Zn, the sulfate (ZnSO4) and silicate (Zn2SiO4) compounds were abundant in both the fine and coarse fractions, whereas Zn oxalate (ZnC2O4) was found only in the fine particles and Zn chloride (ZnCl2) only in the coarse particles. The origin of Cr an Zn species in the samples studied seem to be local and anthropogenic, such as combustion and road dust resuspension due to traffic. These first chemical speciation results from Ulaanbaatar city provide enhanced insights in the atmospheric aerosols physiochemical nature as well as information on the potential contributing sources of Cr and Zn species in the two size-fractioned particulates.
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