Characterization of Speciated Aerosol Emissions from Combustion of Furnished Structures

MICHAEL MILAZZO, Nathan Kreisberg, Robert Weber, Wuquan Cui, Bryce Bathras, Siyan Wang, Faraz Hedayati, Michael Gollner, Allen Goldstein, University of California, Berkeley

     Abstract Number: 495
     Working Group: Burning Questions of Aerosol Emissions, Chemistry, and Impacts from Wildland-Urban Interface (WUI) Fires

Abstract
The number of structures destroyed in fires has risen in recent decades due to the increasing severity of wildland fires and expanding development at the Wildland-Urban Interface (WUI). Although previous research has characterized smoke emissions from individual anthropogenic fuels, limited data exist on emissions from fully furnished, burning structures. We measured emissions from a series of structure-to-structure fire spread experiments using full-scale Accessory Dwelling Units (ADUs). These ADUs were constructed according to the California Building Code and furnished with typical household contents, including appliances, bathroom fixtures, a couch, television, and clothing.

Emissions were measured and collected using a custom sampling package aboard a drone that followed the smoke plume in real time. Online continuous measurements of CO and CO₂ enabled calculation of the modified combustion efficiency (MCE). Time-integrated samples of particulate matter were collected to quantify PM_2.5 mass, organic carbon (OC), elemental carbon (EC), speciated elemental composition via inductively coupled plasma mass spectrometry (ICP-MS), and organic aerosol speciation via thermal desorption two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (TD-GCxGC-HToF-MS).

We report CO₂-based emission factors for speciated PM_2.5 from the combustion of multiple ADUs. We contextualize the observations by MCE, building materials, and notable fire events. Elemental analysis revealed high emission factors for potassium and sulfur, which have been observed in studies of biomass burning emissions. Strong correlations among certain metals suggest they are emitted together from specific household materials or combustion events.

These findings will contribute valuable data to emissions inventories of WUI fires and will improve air quality predictions during these events. Furthermore, they will support improved regulatory modeling of health and economic impacts associated with WUI fires, and could inform choices of building material in future policy.