Los Angeles wildfires: The unique dangers of urban wildfire smoke

As wildfires rage across Los Angeles, the smoke billowing into the air carries more than the expected risks of particulate matter and carbon emissions.

As wildfires rage across Los Angeles, the smoke billowing into the air carries more than the expected risks of particulate matter and carbon emissions.

Urban wildfires, unlike those in remote forests, burn through large areas of neighbourhoods filled with synthetic materials like plastics, rubber, fiberglass and treated asphalt, releasing a cocktail of hazardous chemicals into the air.

“Wildfire smoke when it’s purely burning biomass is bad enough. But when there are large fires in the wild and urban interface, then you get all these kinds of smoke and toxins that are from structural fires,” said John Balmes, a professor emeritus at the University of California, San Francisco, and the University of California, Berkeley.

“It’s much more toxic. The combination of burning biomass and structural fire smoke… like the Palisades fire, that is blocks and blocks of homes, that is particularly toxic smoke,” he added.

As of Friday, the fires have engulfed iconic Los Angeles neighborhoods, killing 10 people so far and destroying nearly 10,000 structures. The fires have torn through buildings, roads, cars and bridges.

On Friday, air quality in the Los Angeles area remained “unhealthy”‘ due to the multiple wildfires ravaging the region.

But wildfires can travel long distances, and the harmful particles they produce can cross the country and even the continent, Balmes warned.

Here’s what to know about the risks of wildfire smoke when fires hit cities.