The Marshall Fire, a wildfire that swept through Boulder County in December 2021, caused negative physical health effects for residents of homes within two miles of the fire for up to two years afterward, according to a recent study. The study found that 55 percent of survey respondents continued to experience physical symptoms of smoke exposure six months after the fire stopped burning, and about 33 percent of respondents still had symptoms two years after the destructive blaze burned down more than 1,000 homes and businesses.
The study collected 642 surveys about physical health effects caused by the fire after six months and 413 surveys after one year. Co-author Colleen E. Reid wrote that nearly the same percentage also reported at least one symptom two years after the fire, but did not explain how the two year data was collected.
The most common symptoms were itchy or watery eyes (33 percent of respondents), headache (30 percent), dry cough (27 percent), sneezing (26 percent), and sore throat (23 percent). The study, called “Physical Health Symptoms and Perceptions of Air Quality among Residents of Smoke-Damaged Homes from a Wildland Urban Interface Fire,” was released in late December, 2024, about three years after the fire tore through Boulder.
Fire crews are continuing containment efforts in Los Angeles as the Palisade Fire and Eaton Fire have burned more than 14,000 structures since the fires began on January 7. Los Angeles residents impacted by the fire will have to work through insurance claims and potential long-term health effects similar to those experienced by survivors of the Marshall Fire.
Survivors of the Marshall Fire have been communicating with Los Angeles residents through a Facebook group called “From the Mountains to the Beach.” In the Facebook group, Marshall Fire victims have expressed the difficulty in working with insurance companies in the aftermath of a wildfire. Nearly a dozen insurance companies including State Farm and Allstate, have left California due to increased wildfire risks and proposition 103, which prevents insurance companies from raising rates more than 6.9 percent without a mandatory public hearing.
One Boulder resident in the Facebook group commented on a post saying that her family fought the insurance company to pay for remediation efforts but only received “pennies on the dollar” for the total cost the family incurred. Another resident said her family had the home professionally cleaned right after the fire, but it is still uninhabitable more than three years later. Another resident found out last month that her home requires remediation, but the deadlines have passed for filing insurance claims.
Reid explains that house fires are dangerous because chemical smoke can travel between door and window cracks to contaminate nearby homes. These chemicals stick to indoor surfaces like walls and will continue to release toxic compounds for weeks to months after the original contamination event.
The authors of the study found elevated levels of polycyclic aromatic hydrocarbons (PAH) and volatile organic compounds (VOCs). “Research-grade instrumentation” was used to collect samples from one “heavily impacted home in Superior, and “low-cost sensor packages” were sent to ten other homes. Sample collection began ten days after the fire and lasted for about five weeks. Some VOCs are toxic and carcinogenic, including dioxins and benzene. Short-term exposure to PAH can cause eye irritation, nausea, and vomiting, while long-term exposure can cause breathing difficulties, kidney damage, and liver damage.
Boulder County did not issue any health or environmental warnings in the aftermath of the fire before lifting evacuation orders. As areas of Los Angeles have evacuation orders lifted, there has been no mention of potential health effects from the destruction of buildings by the Los Angeles Fire Department.
Insurance companies determine what remediation efforts can be covered after a wildfire. According to a resident who lived through the Marshall Fire, one insurance company covered debris cleanup, but that did not include ash deposits that could contaminate homes and backyard gardens with toxic compounds like dioxins and other VOCs.
