AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Indoor Indirect Emissions from Smoking in a Summertime Classroom
ANITA AVERY, Michael Waring, Peter DeCarlo, Drexel University
Abstract Number: 537 Working Group: Indoor Aerosols
Abstract The chemistry of the indoor environment is influenced by a combination of outdoor aerosols and indoor emissions. To analyze the impact of varying pollutant sources, measurements were made simultaneously outdoors and in a classroom at Drexel University in Philadelphia in two seasons: August 2014 and February 2016. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) measured size-resolved non-refractory chemical components while black carbon and size distribution were measured using an aethalometer and scanning electrical mobility system (SEMS). For AMS measured sulfate, nitrate, and organic material, measured median indoor to outdoor concentration ratios were 0.37, 0.55, and 0.39, respectively. The organic aerosol (OA) measured with the AMS was further analyzed with positive matrix factorization (PMF). PMF results revealed some factors previously identified outdoors, including oxygenated OA (OOA), hydrocarbon-like OA (HOA), as well as a new factor, an indoor-originated OA (IOOA) factor. In both environments, the HOA factor followed daytime traffic patterns from nearby highway sources, COA followed patterns of lunchtime and evening outdoor cooking, and OOA peaked in the evening consistent with photochemical aging. The IOOA contained high nitrogen content and is consistent with “third-hand” cigarette emissions. This factor was not seen in the outdoor aerosol dataset and contributed 29% of the total submicron aerosol loading indoors. The classroom was located close to an outdoor balcony frequently used for illicit smoking, but changes in IOOA concentrations were variable over hours, indicating that it is emitted over time after deposition indoors. Impacts of occupancy on submicron aerosol composition is also investigated with increasing CO2 levels used as a proxy for occupancy. Aerosol composition and ozone levels pre, during, and post occupancy will also be discussed.