The infernal blazes burning in Southern California are raising concerns about the potential airborne hazards they may be leaving behind.

Even once the fires are ultimately extinguished, experts warn, contaminants from the structures they've destroyed — some of them potentially containing toxic materials — could linger in the air and pose uncertain health hazards.

While just how many buildings have burned remains inconclusive, estimates indicate that at least 15,000 structures succumbed to the flames of the initial Palisades and Eaton fires. And some "will have experienced significant damage from smoke and toxic ash deposits," noted Daniel Swain, a University of California, Los Angeles, climate scientist, at a webinar earlier this week.

"This is a growing concern in the wake of this highly urban fire that burned not just vegetation, but a whole lot of structures that contain things like lead paint, asbestos, various heavy metals contained in the batteries that burned in vehicles and in home system backups and solar panels," he said.

Describing these losses as "a staggering toll," Swain warned of indirect harm residents could endure from smoke and toxic ash exposures.

"The health harms, the illness and sometimes, the death that can result from large scale disasters and wildfires, is not limited only to the people who don't make it out of the fire zone," he added.

Heading into a likely rainy weekend, the Palisades Fire, which has ravaged the Pacific Palisades neighborhood, was 23,448 acres and 77 percent contained. The Eaton Fire, north of Pasadena, was 14,021 acres with 95 percent containment. But the new Hughes Fire, which began Wednesday near Castaic Lake, had grown to 10,396 acres and was only 56 percent contained.

Wildfire smoke contains a mixture of pollutants, although the most well-studied ingredient is fine particulate matter (PM 2.5). When inhaled, these tiny particles can invade the lungs and penetrate the bloodstream, noted Tarik Benmarhnia, a climate change epidemiologist at the University of San Diego's Scripps Institution of Oceanography,

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