A Comparison of Summertime Secondary Organic Aerosol Source Contributions at Contrasting Urban Locations

作者：Stone, Elizabeth A.; Zhou, Jiabin; Snyder, David C.; Rutter, Andrew P.; Mieritz, Mark; Schauer, James J.^*

来源：Environmental Science & Technology, 2009, 43(10): 3448-3454.

DOI：10.1021/es8025209

• FINE-PARTICLE EMISSIONS
• UNITED-STATES
• CHEMICAL-CHARACTERIZATION
• FIREPLACE COMBUSTION
• SOURCE APPORTIONMENT
• PARTICULATE MATTER
• ELEMENTAL CARBON
• AIR-POLLUTION
• AMBIENT PM2.5
• WOOD

Primary and secondary sources contributing to atmospheric organic aerosol during the months of July and August were quantitatively assessed in three North American urban areas: Cleveland, Ohio, and Detroit, Michigan, in the Midwest region and Riverside, California, in the Los Angeles Air Basin. Organic molecular marker species unique to primary aerosol sources and secondary tracers derived from isoprene, alpha-pinene, beta-caryophyllene, and toluene were measured using gas chromatography-mass spectrometry. Source contributions from motor vehicles, biomass burning, vegetative detritus, and secondary organic aerosol (SOA) were estimated using chemical mass balance (CMB) modeling. In Cleveland, primary sources accounted for 37 +/- 2% of ambient organic carbon, measured biogenic and anthropogenic secondary sources contributed 46 +/- 6%, and other unknown sources contributed 17 +/- 4%. Similarly, Detroit aerosol was determined to be 44 +/- 5% primary and 37 +/- 3% secondary, while 19 +/- 7% was unaccounted for by measured sources. In Riverside, 21 +/- 3% of organic carbon came from primary sources, 26 +/- 5% was attributed to measured secondary sources, and 53 +/- 3% came from other sources that were expected to be secondary in nature. The comparison of samples across these two regions demonstrated that summertime SOA in the Midwestern United States was substantially different from the summertime SOA in the Los Angeles Air Basin and indicated the need to exert caution when generalizing about the sources and nature of SOA across different urban areas. Furthermore, the results of this study suggest that the contemporary understanding of SOA sources and formation mechanisms is satisfactory to explain the majority of SOA in the Midwest. Additional SOA sources and mechanisms of formation are needed to explain the majority of SOA in the Los Angeles Air Basin.

• 出版日期2009-5-15
• 单位武汉理工大学