Chemical Characteristics of Indoor Aerosol Particles and Surface Films
RACHEL O'BRIEN, Amy Hrdina, Cate Shirilla, Emily Heery, Kathryn Mayer, Dustin Poppendieck, Marina Vance, Delphine K. Farmer,
University of Michigan Abstract Number: 192
Working Group: Indoor Aerosols
AbstractIndoor surfaces and the films on them play important roles in indoor air quality due to the high surface area to volume ratios in our homes. These films are formed from the deposition of aerosol particles and the sorption of semi-volatile organic compounds and are thus often complex mixtures of organic chemicals. The chemical complexity can expand even further after film formation as the chemicals in the mixture react and age on the surface. The composition of these films will play a role in their behavior indoors, so an improved understanding of the important chemical classes found in these films will help model predictions for partitioning of organic chemicals in indoor air. Important sources for chemicals in these films are cooking, cleaning, and aerosol particles from outdoors including wildfire smoke. Cooking can be a large source for semi-volatile and lower volatility organic compounds. Cleaning processes can generate aerosol particles and leave behind lower volatility material on indoor surfaces. Depending on the distance of the building from the fire, biomass burning organic aerosol particles (BBOA) can reach indoor spaces at different levels of aging. Here, we investigate the chemical composition of surface films formed on impermeable surfaces during different activities. Intact films formed on coupons that were deployed during the campaign are compared to films aged with ozone and higher relative humidity (RH). We also investigate the correlations between this composition, and the composition of size resolved aerosol particles collected at the NIST (National Institute of Standards and Technology) Net-Zero Energy Residential Test Facility during the CASA (Chemical Assessment of Surface and Air) field campaign.