AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Spatial and Seasonal Trends in Polycyclic Aromatic Hydrocarbon Particulate Measurements in Ulaanbaatar, Mongolia
Skyler Simon, AUDREY DANG, Jay R. Turner, Rufus Edwards, Brent Williams, Washington University in St. Louis
Abstract Number: 791 Working Group: Urban Aerosols
Abstract Ulaanbaatar, Mongolia is globally the coldest capital city. Poor wintertime air quality is influenced by distributed space heating (including inefficient residential coal stoves) and other emission sources, strong inversions, and a topography that further traps ground-level emissions. Ambient PM2.5 field sampling was conducted January to April 2013 across four sites with offline analysis for chemical components. More recently, a subset of 80 archived samples (20 samples per site) were analyzed by Filter Thermal desorption Aerosol Gas Chromatography – Mass Spectrometry (Filter TAG) for organic species including particle-bound polycyclic aromatic hydrocarbons (PAHs). To date 18 PAHs have been quantified using authentic standards and surrogate standards, and additional unquantified PAH material is present in the samples. The grand average (across all sites and sampling dates) 24-hour integrated summed ∑PAHs was 1.3 μg/m3 (range 0.1-4.6 μg/m3) with strong seasonal variation in both concentration and carcinogenic potency. ∑PAHs spatiotemporal variability across the four sites was characterized by Pearson correlation coefficients 0.84-0.92 and coefficients of deviation (COD) 0.18-0.35; these metrics demonstrate relatively high homogeneity across the city. Positive matrix factorization (PMF) was used to resolve PAH sources and atmospheric processes.