Matt Rahn was about 200 feet away when flames started climbing up the side of the garage and creeping toward the car inside.
A wildfire researcher with California State University San Marcos, Rahn was at the edge of a fire that would go on to burn 4,240 acres across California’s Amador and El Dorado counties. He was there to study the smoke rising off blackening shrubs and trees. Watching the garage burn, though, he realized that firefighters fending off flames without any real lung protection were inhaling more than airborne remnants of burnt plants.
“Think about the average home, all the chemicals and things that are in there, not to mention all the building materials and furniture,” said Rahn, who also is a member of Temecula’s city council. “That’s when we started really thinking about what happens. What’s in the smoke when you have all that complicated fuel being combusted at the same time?”
That was in 2014, when wildfires burned 568 buildings across the state. Fire season is not yet over this year and the toll already is higher: three people dead and 732 buildings burned. And the state is still recovering from back-to-back years of catastrophic fires that killed 137 people and damaged or destroyed nearly 35,000 buildings.
As climate change primes the West to burn and more people build closer to nature, the question of what’s in the smoke when fires tear through wilderness and homes alike is still far from being answered. Yet the health of those breathing the smoke — like the firefighters battling the flames — depends on real data.
“Right now, we’re trying to keep California from burning down,” said Michael McLaughlin, chief of the Cosumnes Fire Department and legislative director of the California Fire Chiefs Association. “But how do we put emphasis on those that we’re putting between the fire and the communities we’re trying to save?”
“On people’s radar”
When a wildfire burns through grasslands, forests, and chaparral, the blaze churns out fine airborne particles that can irritate the lungs and have been linked to heart and lung problems, as well as premature death. Deadly gases like carbon monoxide and irritating, potentially cancer-causing chemicals like polycyclic aromatic hydrocarbons mix into the smoke cloud as well.
It’s a complex soup with ingredients that can change depending on the fuel and the ferocity of the fire. And as the chemicals stew in the atmosphere, they continue to react — breaking apart and joining together to create new ingredients to inhale.
Burning buildings and cars typically make up only a small proportion of wildfire smoke, according to Shawn Urbanski, a research physical scientist at the Missoula Fire Sciences Laboratory — but their contributions are starting to capture scientists’ attention. “With these recent fires, it’s really sort of gotten on people’s radar,” Urbanski said.