A recent study has unveiled a troubling reality: hazardous gases harmful to human health lingered in the air for weeks after the Marshall Fire—Colorado’s most catastrophic wildfire.
This disaster incinerated nearly 1,000 homes and forced over 37,000 residents in Boulder County to evacuate their neighborhoods.
Research Overview
Researchers from the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado Boulder conducted this investigation.
Their findings shed light on a concerning issue—indoor air quality in homes near the fire zone is noticeably worse, with pollution levels resembling those of urban Los Angeles in the 1990s.
This information is crucial for residents considering a return home after such a devastating event.
While many houses were completely destroyed, others looked relatively unharmed from the outside.
However, the inside often harbored persistent odors and evidence of residue, such as black ash.
Responding to community concerns, CIRES researchers embarked on a study focused on a typically neglected area: understanding air quality in regions where wildfires meet urban environments, known as the Wildland Urban Interface (WUI).
Findings and Implications
About ten days after the fire, the team set up air quality measurement instruments in a house in Superior, Colorado.
Nearby residents reported strong smoke infiltration and a lingering campfire scent caused by wind patterns.
Led by Will Dresser, a PhD chemistry student, the team discovered that dangerous gases remained trapped indoors long after the flames were extinguished.
The frequency of WUI fires has surged in recent years, yet research on their impact on air quality is limited.
The study revealed a troubling reality: materials commonly found in WUI fires—including wooden structures, vehicles, and household items—emit elevated levels of harmful volatile organic compounds (VOCs).
- Indoor concentrations of aromatic VOCs, like benzene, toluene, and naphthalene, were significantly higher than those found outdoors.
- VOC levels inside homes were reminiscent of those recorded in Los Angeles during the 1990s.
- VOC levels initially decreased rapidly, but the decline slowed significantly over a five-week span.
- Homes acted like sponges, slowly releasing trapped pollutants back into the indoor air.
This study challenges a prevalent assumption: past research suggested that VOCs would dissipate within hours.
However, this investigation shows that these substances can persist for weeks in indoor environments, revealing a critical gap in our understanding of how these pollutants accumulate and linger.
Mitigation Strategies
To tackle the elevated VOC levels, researchers explored various ventilation strategies, such as opening windows.
While this approach did reduce VOC concentrations, those levels rebounded quickly once the windows were shut again.
They also crafted DIY air cleaners that effectively lowered VOC levels while in operation; however, similar increases were observed once they were turned off.
Though this investigation centered on one household following a single WUI incident, it’s essential to recognize that different situations could lead to varying environmental outcomes.
With the likelihood of more frequent and intense WUI fires on the horizon, these findings serve as a vital resource for residents weighing their options after such calamities.
Understanding the implications of indoor air quality post-wildfire is more critical than ever.
Source: ScienceDaily