10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Seasonal Changes in Organic Aerosol Composition in Ulaanbaatar, Mongolia
SKYLER SIMON, Audrey Dang, Brent Williams, Jay R. Turner, Washington University in St. Louis
Abstract Number: 872 Working Group: Aerosol Chemistry
Abstract Ulaanbaatar (UB), Mongolia is the coldest capitol city in the world and has faced persistent air quality challenges driven largely by wintertime space heating demands. For example, in 2016 the PM2.5 mass concentration measured at the US Diplomatic Post in UB had an annual average >70 μg/m3 with a wintertime (November-February) average >160 μg/m3 and summertime (June-September) average <20 μg/m3. Previous measurements demonstrate wintertime PM2.5 is dominated by organic matter, perhaps as much as 85% of PM2.5 mass. This is consistent with the primary sources of space heating being coal combustion in residential heating stoves in gers (yurts) and ger-area houses, heat-only boilers for schools and other small facilities, and combined heat and power plants that serve the central business district. However, there is little information on detailed organic speciation which could be valuable to understand emissions sources and health impacts.
We present results from organic speciation of 24-hour integrated ambient particulate matter samples collected on quartz filters at four sites across UB from January to April of 2013 [1]. These samples were thermally desorbed and analyzed off-line by gas chromatography – mass spectrometry using a Filter Thermal Desorption Aerosol Gas Chromatograph-Mass Spectrometer (Filter TAG). Individual molecular markers are identified and quantified, including polycyclic aromatic hydrocarbons which are known to have adverse health effects. Additionally, positive matrix factorization (PMF) solutions of binned chromatograms are used to investigate how seasonal trends in sources such as coal burning contribute to changes in ambient organic aerosol speciation [2].
[1] “Health assessment of future PM2.5 exposures from indoor, outdoor, and secondhand tobacco smoke concentrations under alternative policy pathways in Ulaanbaatar, Mongolia”, L.D. Hill, R. Edwards, J.R. Turner, Y.D. Argo, P.B. Olkhanud, M. Odsuren, S. Guttikunda, O. Chimedsuren, and K.R. Smith, PLOS ONE, 2017. [2] “A technique for rapid gas chromatography analysis applied to ambient organic aerosol measurements from the thermal desorption aerosol gas chromatograph (TAG)”, Y. Zhang, B.J. Williams, A.H. Goldstein, K.S. Docherty, I.M. Ulbrich, J.L. Jimenez, Aerosol Science and Technology, 2014.