Spatial and Seasonal Variations in the Composition of Organic Aerosols Collected During the Cleveland Multiple Air Pollutant Study

IVAN PILETIC, Jonathan Krug, John Offenberg, Mohammed Jaoui, John Turlington, David Olson, et al.

US Environmental Protection Agency

     Abstract Number: 142
     Last modified: April 1, 2011

Abstract
The carbon content of PM2.5 (aerosol) particles collected around Cleveland Ohio was comprehensively investigated using several analytical methods, each possessing varying degrees of chemical sensitivity and specificity. In the Cleveland Multiple Air Pollutant Study (CMAPS) field campaign, aerosol particles were collected on a daily basis at three sites (GT Craig, Fire Station 13 – downtown Cleveland Ohio and Chippewa Lake – near Medina Ohio) during August 2009 and February 2010. Multiple sites (urban versus rural) and multiple time periods (summer versus winter) allowed for a thorough examination of spatial and seasonal aerosol composition variance. During the summer and winter sampling periods, total organic and elemental carbon concentrations were determined at all three sites while 14C data were obtained at the GT Craig and Chippewa Lake sites. The latter analysis determined the fraction of ‘modern’ carbon which is important for discerning the relative contribution of petroleum to organic aerosols. Additionally, primary and secondary organic aerosols were investigated by more specific organic tracer-based methods capable of discerning biogenic and anthropogenic sources of PM2.5. The tracers that were quantified included: primary organic aerosol tracer compounds (polycyclic aromatic hydrocarbons and hopanes), secondary organic aerosol tracer compounds (derived from isoprene, alpha-pinene, beta-caryophyllene, toluene) and a biomass burning tracer (levoglucosan). This comprehensive analysis allows a majority of the carbon in ambient aerosol particles to be inventoried and source apportioned.