The University of Colorado Boulder has published two new research papers examining the air quality inside homes that survived the 2021 Marshall Fire, Colorado’s most destructive wildfire, and its impact on residents’ health. These studies are among the first to investigate air quality within smoke and ash-damaged homes and assess the health effects on occupants.
The first study conducted mass spectrometer sampling of a fire-damaged home during a five-week period starting 10 days after the fire. 1 The research, which included measurements of 50 gases, found that volatile organic compounds (VOCs) begin to decrease after the fire but linger for far longer. Testing detected elevated levels of compounds like benzene, copper, zinc, arsenic, and industrial pollutants, which can cause serious health issues with long-term exposure. The study pointed out that additional “laboratory experiments with different building materials such as drywall and wood are needed to study these processes in detail” and test results “may differ for homes that contain different materials and exchange rates.”
The second study surveyed 859 residents within two miles of the Marshal Fire boundary and documented health symptoms between January 2022 and March 2023. 2 The study revealed that over half of the survivors whose homes remained standing reported health issues such as headache, sore throat, cough, and unusual taste in their mouths due to poor indoor air quality. The study aptly noted that “uncertainty around the health impacts of WUI [Wildfire and the Wildland Urban Interface] fires has contributed to a lack of clear guidance and regulations around home remediation and when it is safe to return to a smoke or ash damaged home.”
Concerns about the long-term health effects and exposure have been a hot topic in Colorado, including the recently passed Colorado House Bill 24-1315 requiring the Colorado Division of Insurance (DOI) to conduct or commission a comprehensive study on the remediation of residential properties damaged by smoke, soot, ash, and other fire-related contaminants. The DOI study aims to examine existing remediation practices and develop recommendations for establishing uniform standards in this area.
The University of Colorado and DOI studies highlight the critical role of addressing post-fire health risks in structurally intact properties. They also serve as important reminders for insurance companies to acknowledge the need for comprehensive testing, ongoing air quality monitoring, and appropriate remediation when properties have been contaminated.
1 William D. Dresser, Jonathan M. Silberstein, Colleen E. Reid, et al. Volatile Organic Compounds Inside Homes Impacted by Smoke from the Marshall Fire. ACS ES&T Air (Dec. 23, 2024).
2 Colleen E. Reid, Jessica Finlay, Michael Hannigan, et al. Physical Health Symptoms and Perceptions of Air Quality among Residents of Smoke-Damaged Homes from a Wildland Urban Interface Fire. ACS ES&T Air (Dec. 23, 2024).