Concerned about LA air quality? Here are 7 expert tips

The ongoing wildfires that erupted across Los Angeles County last week have many residents worried about what they're breathing and how to keep their families safe.

More than 5,000 people tuned in Wednesday for a Zoom discussion hosted by the California-based Coalition for Clean Air, during which air-quality advocates and public health experts warned attendees to consider the short- and long-term health effects of this disaster.

“We now have the largest urban fire in the country's history,” said Jane Williams, executive director of California Communities Against Toxics.

“Just for perspective, we've now burned down [an area] like the entire city of San Francisco.”

The experts said that even after the fires are extinguished, health risks from ash, smoke and toxic materials that linger in the air can persist for months or years — especially in or near burn areas. The toxins aren't always visible or detected by standard air quality measurements, making it hard to understand how to protect yourself.

Here are seven tips from the experts for minimizing your health risks during and after L.A.’s wildfires.

1. Don't rely solely on AQI readings

The Air Quality Index is a very useful metric for tracking particulate matter under normal circumstances, but it provides an incomplete picture of the current health risks in Los Angeles, experts and air quality advocates say.

The readings fail to detect many toxic chemicals present in wildfire smoke and ash.

“The AQI does not measure the contaminants and pollutants that we really care deeply about here because they’re extremely expensive to measure,” Williams told the audience.

The AQI measures the amount of tiny inhalable particles in the air, including those 30 times smaller than the width of a human hair. Everyday sources of particle pollution include vehicle exhaust, power plant emissions and construction dust.

In these urban wildfires, countless airborne toxic chemical compounds from burned materials have been absorbed onto those tiny particles, which get lodged inside your lungs and can have enormous health impacts — ranging from bronchitis to cancer, Williams said.

“You're really looking at the type of problems that occur when you've dropped a bomb on a city,” Williams said. “It's really unprecedented in the country's history.”

The particle pollution from wildfire smoke can be up to 10 times more harmful to human lungs than the typical particles that come from traffic or power generation, according to researchers with the Scripps Institution of Oceanography at UC San Diego, who studied hospital admissions data.

That's because urban wildfire particles carry a more dangerous mix of toxic chemicals from burned buildings, vehicles, electronics, plastics and other materials — unlike the more predictable pollution from vehicle exhaust or power plants.

So even if the AQI is “good” or “moderate,” that doesn’t necessarily mean the air is safe, particularly if you are near an active fire or burn scar. Use your senses too. If you can see ash or smell smoke, take precautions regardless of what air quality monitors show.

2. Treat ash as hazardous material

If you can see ash deposited on your window sills, vehicles or the ground outside, that’s an indication that wildfire smoke has been blowing your direction, even if you’re not in the immediate vicinity of a fire, said Dr. Ed Avol, professor emeritus at USC Keck School of Medicine.

That ash is likely contaminated with a complex mixture of toxic substances, and it's not possible to know exactly what toxic chemicals and metals you're breathing when ash particles get into the air.

Before trying to sweep up the ash, Avol recommends wetting it down with a garden hose. Use a protective respiratory mask and HEPA-filtered vacuum to reduce risk of health effects. Don't use a leaf blower.

“We're talking about relative risk here,” said Avol. “There's no zero risk, of course, but we try to do what we can to reduce the risk.”

People returning to ash zones or burned areas should always wear protective equipment:

• Wear a tight-fitting N95 mask at the bare minimum, but a P100 is better, experts say. 
• Wear long sleeves, eye protection, closed-toed shoes and cut-resistant gloves. 
• Clean or decontaminate anything that’s been in contact with ash.
• Don’t try to salvage heavily contaminated items.

Any time you disturb the ash, by sweeping it or just walking through it, you’re creating particles which can be inhaled and damaging to your health and the health of others.

“The air quality index may say something, but that is totally not applicable to us walking on a site that's still smoldering, or smoke coming our way from wind, or us sweeping the dust,” said Dr. Rania Sabty, a Los Angeles-based environmental health specialist.

Tips from the regional agency responsible for regulating air quality

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South Coast Air Quality Management District

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3. Be careful with vulnerable groups

Some people are more susceptible to the health effects of exposure to smoke, soot and ash than others. You should take increased precautions and avoid ash zones if you’re pregnant, over 65 or have a respiratory condition, including asthma.

Small children should be kept inside as much as possible in filtered air environments, as exposure could do long-term damage to their developing lungs. If you don’t have the capacity to purify the air in your entire home, experts said to consider creating a “clean room” — putting an air purification unit with MERV-13 or higher rated air filters in the one room of your home where children or other vulnerable people spend the most time.

The most effective purifiers are HEPA filter carbon filter purifiers, experts say. Avoid ozone-generating purifiers by making sure your air filter is certified by California’s Air Resources Board.

4. Don't rush to return to 'normal'

The psychological and social pressure to resume regular activities can lead to unsafe choices, according to experts. If you live or work in or near an evacuation zone, take time to ensure areas are truly safe.

“This rush to try to return to normalcy, you end up exposing people to really horrific public health impacts,” said Williams. “It will probably take us at least two years, if we were really fast, to get all this ash excavated.”

This week, L.A. County’s Public Health Officer issued an order prohibiting cleanup or removal of fire debris at properties in critical fire areas until a government agency has completed a hazardous materials inspection.

Williams said residents living in ash zones who are concerned about their health should think twice before returning.

“There's a lot of this tension in our future between wanting to rebuild and return to normalcy and trying to protect public health from the cleanup itself and from the ash,” Williams said.

5. Stay informed about cleanup efforts

Because ash removal can take years, experts recommend keeping a close eye on cleanup and removal efforts in your community. Monitor wind conditions during cleanups. Report improper cleanup practices to the South Coast Air Quality Management District. Be aware of disposal sites, which will also be affected by the toxic material.

“People need to be vigilant,” said Sabty. “And if they're watching ash being removed with trucks that are open, they need to say something about it.”

Toxic particles can be stirred back up into the air long after the fires are out. This can happen during property cleanup, demolition of damaged structures, and reconstruction activities — which means areas near burn zones could face recurring exposure risks for months or years as rebuilding takes place.

6. Consider your location and circumstances

The degree of exposure to toxins if you’re living in or near an evacuation zone is likely higher, but distance from burn zones isn't the only factor. Wind patterns can affect your exposure significantly. In the 2018 Camp Fire in Northern California, smoke containing toxic metals traveled more than 150 miles, according to the California Air Resources Board.

Local conditions, like nearby burned structures, matter more than general air quality readings, experts say. Different neighborhoods may have different toxic exposures.

“Air quality is not measured in every location,” said Tim Dye of TD Environmental Services. “There could be dust in the air. There could be local smoke that's not picked up by these monitors. I think [we should] try to use our senses in that case. Do we see blowing dust? Do we see some smoke? Because we can't rely upon measurements if none exist.”

7. Make informed risk assessments

This is an unprecedented situation, and there are no absolute “safe” distances or perfect answers. You’ll need to weigh multiple factors like location, wind patterns, family health conditions, and work requirements to determine what precautions are right for you and your family, experts advise.

What's an acceptable risk for one person might not be for another.

“It’s hard to give absolutes here,” said Avol. “Safe is in the eyes of the beholder, to some extent.”

It’s good to stay informed, but recognize you’ll need to make judgment calls based on your specific situation. When in doubt, err on the side of caution, especially for vulnerable family members.

“You can't live a life of zero risk,” said Joseph Lyou, president & CEO of the Coalition for Clean Air. “In a disaster like this, you may have to make some difficult choices.”