AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Sources of Organic Aerosol in Eastern Iowa
ELIZABETH STONE, Chathurika Rathanyake, Thilina Jayarathne, University of Iowa
Abstract Number: 176 Working Group: Source Apportionment
Abstract Atmospheric aerosols are micron-sized particles in the atmosphere that have significant consequences on human health and in the regulation of global climate. The climate and health effects of aerosols depend partially on their chemical composition, which is largely determined by the contributing aerosol sources and atmospheric transformations. The ambient atmosphere in Eastern Iowa provides a unique setting to study industrial, motor vehicle, agricultural influences on aerosol composition. Very few aerosol measurements have been made in the Midwestern United States outside of polluted urban areas; this study presents the first detailed characterization of organic aerosol in the state of Iowa. At a natural location in Johnson County approximately 40% of fine particulate matter with diameter less than 2.5 microns (PM2.5) was found to be comprised of carbonaceous material. In this study, the sources of carbonaceous aerosol are explored by the measurement of molecular markers that are unique tracers for aerosol sources. Molecular markers for gasoline vehicles, diesel engines, coal combustion, biomass burning, primary biogenic materials and secondary organic aerosol were measured by solvent-extraction followed by gas chromatography mass spectrometry (GCMS) analysis. The resulting data were used in a chemical mass balance source apportionment model to evaluate the relative contributions of these aerosol sources to ambient measurements.