Why do those whose homes survived the Los Angeles wildfires still face serious health risks?

When Kate Gammon and her family fled their home in Santa Monica, California, during the recent wildfires, they weren’t sure what they would find when they returned.

Although they were not under an evacuation order, Gammon, who suffers from asthma, told CBC News that the air quality was deteriorating quickly and the fires were volatile, so they left on Jan. 8, when the fires were about six kilometers away. Four days later, she returned to find that the house had survived the fire, but she was disturbed to see a layer of ash littering everything in her yard.

“It rains on us at night,” she said. “It’s kind of like big, white, chunky pieces of ash.”

Researchers now say that because of the massive scale of wildfires and the types of structures burning, people who return home when the initial fire danger has passed still face health concerns from airborne compounds in the ash and smoke.

State firefighters are still working to extinguish the two largest fires in Altadena and Pacific Palisades, which have killed at least 27 people and destroyed more than 12,000 structures including homes, schools and banks. Thursday, Los Angeles County Health Officer Any cleanup or removal of fire debris is prohibited until hazardous materials inspections have been completed.

Ash and dirt found in debris from residential and structural fires may contain asbestos. Heavy metals and other hazardous materialsThe health official said, noting that people can be exposed to toxic substances by inhaling ash or fire dust particles, or through contact with skin or contaminated drinking water supplies.

As an environmental journalist, Gammon previously did just that I mentioned on Health risks posed by ash, not only from brush, but also from thousands of charred structures. That’s why she says she avoids touching the ashes and wears a mask outdoors.

Earlier this week, scientists They published their findings About how wildfires burning prairies and urban areas affect indoor air. They studied 2021 Marshall Fire In Boulder, Colorado, where about 1,000 structures burned in eight hours, which may help highlight urban fires like the one that raged in Los Angeles.

Headache after fire, itchy eyes

Colleen Reed, a professor at the University of Colorado, studied the health effects among people who returned to their unburned homes after that fire. She and her colleagues surveyed residents living near burning buildings.

Over the course of about five weeks, they also measured levels of volatile organic compounds (VOCs) in one home that had survived the fires, but was severely affected by smoke.

They found that higher-than-normal levels of VOCs persisted for about a month inside the home before returning to normal indoor levels.

“People who said their homes smelled different after the fire were more likely six months after the fire to have headaches, dry and itchy coughs, watery eyes, a strange taste in the mouth, and sneezing,” said Reed, the environmental epidemiologist.

Reed and her team also surveyed people six months after the fire (642 participants) and again a year later (413 participants). Results included:

• 65 percent of participants reported having ash in their homes after the fire.

• Most participants were less confident about the air quality in their homes and neighborhoods six months after the fire. Most of them regained confidence after one year.

Tips for cleaning up after wildfires

Delphine Farmer, a Canadian scientist at Colorado State University, studies indoor air as part of… an experience At the US National Institute of Standards and Technology in Gaithersburg, Maryland, she and her team analyzed the composition of particles inside a house-turned-laboratory, after they introduced wildfire smoke.

The farmer found it Smoke buries itself in painted surfacesIt then begins to slowly return to the air, meaning residents are exposed to indoor pollutants for a long time after the fire.

Watch | The science of indoor air after wildfires:

To provide a guide for people who need to clean up after a fire, scientists are also studying how different air cleaners work and how cleaning surfaces affects air quality.

Based on your findings, farm-specific cleaning recommendations include:

• Open windows as soon as the smoke pollution has cleared. The sooner you clean up the smoke, the better.
• Wash fabrics such as bedsheets, clothes, and curtains that may contain smoke.
• Vacuum floors. Wear an N95 mask while doing this as it may stir up soot or smoke residue.
• Mop floors with soap and water and wipe down every surface you can, including walls if your area has a lot of smoke. Wash ceiling fans and other surfaces that are not cleaned frequently. Change the water as it gets dirty.
• Clean out “hidden spaces” in your home such as attics, basements, closets, and garages.
• If your HVAC system is running, consider having it professionally cleaned. Change the filters on your home’s HVAC system or air purifiers and run fans frequently.
• Vacuum and wash the furniture as soon as possible. If you still smell smoke, consider a deep cleaning or replacement.