The Wildfire Danger We’re Only Just Beginning to Understand

The narrative surrounding wildfires has traditionally focused on rural devastation, with images of charred landscapes and fleeing wildlife etched into our collective memory. However, recent years have shown that this is no longer an exclusively rural problem. As the urban-wildland interface expands, wildfire danger has moved closer to home for America’s cities, exposing residents to a toxic mix of smoke and chemicals that threatens their health.

The presence of burning plastics and metals in urban wildfires has become increasingly common. The 2025 Los Angeles County fires exemplified this trend, with large swaths of the city engulfed in flames producing complex and potentially more toxic forms of smoke. When over 16,000 buildings, household items, and electric vehicles burned, they released a cocktail of pollutants into the air.

Research suggests that exposure to particulate matter (PM 2.5) from wildfires is associated with premature death, severe damage to respiratory health, and cognitive impairment. A study published in February found that accumulated exposure to wildland smoke was linked to a greater hospitalization risk for cardiovascular diseases in older Americans, even at moderate levels of PM 2.5.

The changing nature of wildfire smoke is not the only concern. As human structures and vehicles burn, they release chemical toxins into the air, including plastics, metals, and vehicle fuel. The World Health Organization has warned that PM 2.5 is associated with a range of health risks, from respiratory problems to cardiovascular disease.

Suburban expansion into wilder regions has created a perfect storm of risk. According to the US Forest Service, there was a 46 percent increase in the number of houses in the WUI zone between 1990 and 2020. This trend is expected to continue as global temperatures rise and drought conditions worsen.

As we build more homes on the edge of wildfire-prone areas, we are essentially creating a ticking time bomb of health risks. The math is simple: as suburbia expands into wilder regions, the fire risk grows greater, and so do the health threats.

To mitigate these risks, policymakers must invest in wildfire mitigation strategies, such as creating defensible spaces around homes and promoting sustainable land use practices. Communities should also educate residents about the risks associated with urban wildfires, provide resources for those affected by smoke exposure, and support research into the long-term health effects of wildfire smoke.

Ultimately, the changing face of wildfire danger is a reminder that our built environment has become an integral part of the natural world. As we continue to expand our cities into wilder regions, we must acknowledge the unintended consequences of this trend and take action to mitigate the risks. The clock is ticking – literally – as the threat of urban wildfires continues to grow.