AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Contribution of Cooking Emissions to Primary and Secondary Organic Aerosol in Urban Atmospheres
IMAD EL HADDAD, Stephen Platt, Jay Slowik, Claudia Mohr, Monica Crippa, Brice Temime-Roussel, Anaïs Detournay, Nicolas Marchand, Urs Baltensperger, Andre Prévôt, Paul Scherrer Institute
Abstract Number: 117 Working Group: Aerosol Chemistry
Abstract Recent, Positive Matrix Factorization (PMF) techniques applied to ambient aerosol mass spectrometer (AMS) data identified primary cooking emissions (COA) as one of the main sources of primary organic aerosol (POA) in major cities like London, New York and Beijing, contributing up to 30% of OA. Cooking processes can also be associated with volatile organic compounds that can act as secondary OA (SOA) precursors, explaining potentially in part the high levels of oxygenated OA (OOA) identified in urban areas. At present, the main cooking activities emitting primary OA and the secondary aerosol production potential (SAPP) of these emissions remain virtually unknown.
The approach adopted here is multi-dimensional, involving ambient measurements of COA contribution in European megacities, as well as laboratory quantification of PM and VOC emission factors from the main primary COA emitting processes and their SAPP. Primary emissions from deep-fat frying, vegetable boiling, vegetable frying and meat cooking were analysed under controlled conditions after ~100 times dilution for different oils, meats and vegetables. An AMS and a high resolution proton transfer time-of-flight mass spectrometer (PTR-ToF-MS) were used to quantify OA and VOC emissions, respectively. SOA production potential of the different emissions was quantified by introducing them into the new PSI mobile smog chamber where they were photochemically aged.
Our AMS measurements in Paris and Barcelona showed that cooking emissions constitute a predominant source of urban OA. In the case of Barcelona for example, COA contributed, on average, 17% to total OA. Laboratory measurements of primary emissions suggest that COA identified in ambient atmospheric aerosols is mostly related to fat release from frying with vegetable oils or grilling fatty-meats. In contrast, vegetable cooking was associated with significant VOC emissions. Emission factors and SAPP from all these processes and their potential contribution to ambient OA in urban areas will be discussed.