Concerns about airborne hazards are being raised by the infernal fires burning in Southern California.
Experts warn that even after the fires have been extinguished, the contaminants in the air from the destroyed structures — some of which may contain toxic materials — can linger and pose health risks.
Although the exact number of buildings that have been destroyed is still unknown, it’s estimated that the Palisades Fire and the Eaton Fire consumed more than 15,000 structures. Daniel Swain of the University of California Los Angeles’ climate science department said that some buildings “will have suffered significant damage due to smoke and toxic deposits” during a webinar this week.
He said, “This is an increasing concern after this urban fire which burned not only vegetation but also a lot of structures containing things like lead, asbestos, and various heavy metals in the batteries used in vehicles, home backup systems, and solar panels.”

Swain described these losses as a “staggering toll” and warned residents of the indirect harm they could suffer from smoke or toxic ash.
He added that “the health harm, illness, and even death, which can result from disasters of this scale and wildfires is not only limited to those who do not make it out.”
The Palisades Fire that has devastated the Pacific Palisades area is now 23,448 acres in size and 77 percent contained. Eaton Fire north of Pasadena was 14,021 acres with 95 percent containment. The Hughes Fire, which started Wednesday near Castaic Lake and has grown to 10,396 acres, is only 56% contained.
In addition to fine particulates (PM 2.5), wildfire smoke also contains other pollutants. In a recent explainer, Tarik Benmarhnia a climate change epidemiologist at Scripps Institution of Oceanography of the University of San Diego, explained that these particles can penetrate the bloodstream and invade the lungs when inhaled.

Benmarhnia said that in addition to aggravating existing conditions such as asthma, repeated exposure to PM 2.5 is associated with future lung disease, cardiovascular disease, and dementia. His colleagues and he recently showed how repeated exposure to PM2.5 from wildfire smoke can increase the risk for dementia and Alzheimer’s.
Scripps Oceanography researchers revealed Tuesday that they had identified ash, debris, and embers as far as 100 miles off the coast. This has prompted concern over the potential impact on fisheries and the wider food web.
In a press release, project leader Julie Dinasquet stated that “these fires not only consume vegetation but also massive quantities of urban infrastructure.” This adds a new component called ‘urban ash’ to the wildfire, which is filled with extremely toxic materials.