The Chemistry of Wildfire Smoke in the Indoor Environment during the CASA Campaign

KATHRYN MAYER, Jienan Li, Lauren A. Garofalo, Liora Mael, Andrew Martin, Michael Link, Dustin Poppendieck, Marina Vance, Delphine K. Farmer, Colorado State University

     Abstract Number: 167
     Working Group: Biomass Combustion: Outdoor/Indoor Transport and Indoor Air Quality

Abstract
Climate change and land management practices have resulted in increasing numbers of severe wildfires over the last several decades in the US, which in turn negatively affect air quality for millions of people. Due to the negative health effects associated with wildfire smoke, officials generally recommended that people stay inside during smoke events; however, very little is known about how wildfire emissions affect indoor air quality. During the Chemical Assessment of Surfaces and Air (CASA) campaign, we studied the chemical transformation of wildfire smoke in a 4,100 ft² (380 m²) test house located at the National Institute of Standards and Technology. Briefly, ponderosa pine wood was burned as a proxy for wildfire smoke and injected into the test house, which has an air change rate of ~0.24 hr^-1. Experiments included injections of fresh smoke, as well as smoke that had been aged by exposure to ozone. The chemical and physical properties of the smoke were monitored using a suite of instruments, including a high-resolution aerosol mass spectrometer (HR-ToF-AMS), which measures size-resolved submicron non-refractory aerosol composition. In addition, sub- and supermicron aerosol size distributions and black carbon concentrations were measured, as well as a suite of gas-phase measurements. Preliminary findings suggest that there are significant differences between the chemistry of fresh and aged smoke. Future results will explore the fate and chemical evolution of wildfire smoke in the indoor environment.