EC-15. Measurements of VOCs in Homes Impacted by Smoke from the Marshall Fire

Abstract
The Marshall Fire was one of the most destructive fires in Colorado history, and burned and damaged over 1000 structures in Boulder County. In the immediate aftermath of the fire, there was an intense interest in accessing the persistent air quality effects of the fire both due to its close proximity to major population centers as well as the unique nature of the fire fuel, mostly man-made structures as opposed to biomass. While smoke emissions from traditional wildfires have been well studied and characterized, the emissions from building materials are less well understood and can vary significantly based on the structure. We are interested in how the smoke emissions from this fire infiltrated and then interacted in indoor environments, which have large surface reservoirs, leading to potential persistent indoor air quality effects. In the weeks following the fire, multiple instruments were deployed in a smoke-impacted home immediately adjacent to one of the burn areas to monitor effects for a period of roughly a month. Our measurements focused on gas phase Volatile Organic Chemicals (VOCs) and were carried out with a Vocus Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (Vocus PTR-TOF) and Aerodyne Gas Chromatograph (GC). Both indoor and outdoor levels were measured to look at long term trends and indoor enhancements. Ventilation experiments as well as mitigation tests using Corsi-Rosenthal boxes were done, and analyzed with respect to changes in indoor VOC concentration and exposure. Smoke remediation took place during the study, and the data give insight into enhancements in VOCs before, during, and after the cleaning.