Aerosol Emissions from Structural Fires at the Wildland-Urban Interface: From Carpets to Couches and Shingles to Studs

KEVIN RIDGWAY, Anna Helfrich, Jamie Cast, Cristian Medina, Miranda Trujillo, Christian L'Orange, Shantanu Jathar, Colorado State University

     Abstract Number: 511
     Working Group: Chemicals of Emerging Concern in Aerosol: Sources, Transformations, and Impacts

Abstract
With nearly 50 million houses in the US located at the wildland-urban interface (WUI) and wildfire frequency and activity on the rise, there is a growing concern that wildfire-related structural fires might be an important source of aerosols in WUI regions, with implications for air quality and public health. However, aerosol emissions from structural fires are poorly understood and what we do understand remains fragmented and incomplete. In this work, we will report on structural fire experiments performed as part of the Burning Homes and Structural MAterials (BHASMA) project at Colorado State University in the Summer of 2023. More than 80 experiments were performed on 17 different fuels, representing structural wood (e.g., Douglas-fir), manufactured wood (e.g., oriented strand board), insulation (e.g., extruded polystyrene), carpet (e.g., polyester), roofing (e.g., asphalt shingles), electrical sheathing (e.g., polyvinyl chloride), and flooring (e.g., luxury vinyl plank), under pyrolysis and flaming conditions. Aerosol emissions were collected on a combination of Teflon and quartz filters and analyzed offline using a host of analytical techniques. We will describe emissions ratios and emissions factors for PM2.5, inorganic ions (e.g., sulfate, nitrate), organic aerosol (OA), light-absorbing carbon (e.g., black carbon), and trace metals as a function of the fuel type, fuel category, and combustion mode. Further, we will contrast emissions for these structural materials against historical data and develop an emission factor database for use in constructing emissions inventories for structural fires. Our work contributes to the body of literature focused on understanding the environmental and health impacts from WUI fires.