AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Rapid Size and Chemical Characterization of Outdoor and Indoor Particulate Matter, Implications for Transport and Environmental Influence
PETER DECARLO, Michael Waring, Drexel University
Abstract Number: 320 Working Group: Indoor Aerosols
Abstract The size, concentration, and chemical composition of submicron particulate matter (PM) was measured with an Aerodyne Aerosol Mass Spectrometer (AMS) in the winter of 2013. Utilizing a custom inlet switching system, PM was alternatively measured indoors and outdoors with a time resolution of 2 minutes. AMS measurements were conducted in Drexel Air Resources Research Laboratory in downtown Philadelphia. The unique set-up of this experiment allows the interrogation of the chemical and physical changes of PM as it is transported from the outdoor to the indoor environment. Lag time between changes in outdoor concentrations and reflected changes in indoor concentrations is clearly observed and the implications of air exchange in a mechanically ventilated building can be assessed. PM loss processes upon outdoor to indoor transport from deposition and/or volatilization are determined by the relative changes to non-volatile and semi-volatile species (e.g. ammonium sulfate and ammonium nitrate). Detailed changes in submicron size distributions are a combination of the same depositional and volatilization losses. The influence of different sources is investigated using mass spectral features, and factorization techniques such as positive matrix factorization (PMF). The influence of food trucks located on campus are clearly observed in the dataset using the ratio of m/z 55 and m/z 57 in the AMS measured mass spectra. These and other results will be presented.