As Santa Ana wind conditions continue to stoke fears of resurgent wildfires across Los Angeles County, health officials are warning of yet another wind-borne threat: ash and dust from active fire zones and burn scars.

On Tuesday, the county Department of Public Health issued a windblown dust and ash advisory until 7 p.m. Wednesday.

During this time, ash may be dispersed from the Palisades and Eaton fire areas, as well as from the Hurst, Kenneth, Line, Airport and Bridge fire burn scars, according to the South Coast Air Quality Management District.

“Windblown ash particles may be too large to be detected by air quality instrumentation and will not influence Air Quality Index levels,” the advisory stated. “However, ash particles are typically visible to the naked eye either in the air or on outdoor surfaces.”

Experts say that wildfire smoke is unsafe for everyone and that all area residents should be worried about the potential health effects from this pollutant.

The cause for concern is, “the main component of smoke is particulate matter and that can penetrate deep into the lungs, which directly causes respiratory issues, but it can also enter the bloodstream where it can cause a range of other health issues,” said Anne Kelsey Lamb, director of Regional Asthma Management and Prevention.

Wildfire smoke can be extremely harmful to the lungs of at-risk people, who include children whose lungs are still developing, pregnant women, older adults, and those with asthma, chronic obstructive pulmonary disease, chronic heart disease or diabetes, according to the American Lung Assn.

Exposure to air pollution such as wildfire smoke can also lead to the onset of asthma in otherwise healthy people, Lamb said.

As wildfires have become more common researchers have been learning that wildfire smoke, depending on what it consists of, can be even more dangerous to public health than other types of air pollution.

Last year the UCLA Luskin Center for Innovation published a study in the journal Science Advances that found an estimated total of more than 55,000 premature deaths in an 11-year span from inhaling fine particulate matter known as PM2.5, or soot, from wildfires.

Air pollutants from wildfires are dangerous to the immediate fire zone and surrounding communities, but the harm can reach out farther.

Lamb noted that during the 2018 Camp fire in Butte County, researchers found smoke with lead in it 150 miles away from the fire zone.

“Even people who aren’t in the immediate vicinity of the fire are likely still facing some of the impacts of the smoke from it,” she said. “I encourage everyone in the broader area to take the same precautions that we would recommend for someone who’s really right there in the midst of it.”

What’s possibly in the air? In the ash?

We know that wildfire smoke can include toxic materials such as lead, asbestos and arsenic, which can lead to additional health harms, Lamb said.

Part of the reason wildfire smoke from the Los Angeles-area fires is particularly concerning is because — in addition to PM2.5 — the smoke from this disaster can include harmful components that were part of houses, items inside the home, buildings and cars that burned.

Toxic chemicals from plastics, paint from the house and furniture are a few examples of what has been burned and is being released in the air, said Anthony Wexler, director of the Air Quality Research Center at UC Davis.

Researchers are still working to understand the relative toxicity of these specific chemical pollutants during a fire event.

“We’ve done some experiments, some early experiments in my lab showing that it’s more toxic, the building materials than burning wooded material,” Wexler said. “But again, we have just a little bit of data.”

In the face of uncertainty, he said, “people should protect themselves as much as they can.”

Local and regional public health officials are recommending that at-risk people stay indoors with the windows and doors closed — while keeping the indoor air clean.

“You have permission to be a couch potato, as long as you have electricity so you can watch the tube,” Wexler said.

The more you do outside the more you’re going to expose yourself to all the harmful air pollutants.

Wexler advises you whip out the protective gear that you had for the pandemic: air purifiers, N95 masks, gloves and protective eyewear in case you have to go outside.

If I have to be outside, what can I do to stay safe?

If people need to be outside, experts recommend wearing an N95 mask.

That’s because those are really the only masks that are going to filter out the damaging fine particles, Lamb said.

“The surgical masks allow too much air to get in, because it’s not the tight fit,” she said. “It doesn’t filter out as fine of particles as the N95 does.”

Researchers have looked into wearing cloth masks during wildfire smoke and found that it “led to more exposure because some of the smoke sort of settled in the material and then it was continuously breathed in,” Lamb said.

There are a lot of Los Angeles residents who are out in surrounding communities volunteering their time to local disaster relief efforts, providing essential services and working.

“We want people to volunteer and help out, because we need that,” Wexler said.

But there are further safety steps that men with beards should take, he said.

Bearded men need to shave or at least cut back facial hair as much as possible so that a protective mask makes a firm seal around the face, keeping pollutants out.

Experts also urge everyone to remove clothes worn while working outside, including shoes, before entering home. Put the clothes in the wash right away, because some of the particulate they carry can come inside the home and affect other people, Lamb said.

One thing to remember, Lamb said, is that the components of the pollutants, including ash, will settle on the ground and can be aerosolized again when disturbed as part of the cleanup efforts.

“There may be no way to avoid that happening, but to avoid exposure, make sure you’re wearing a mask, and I would even have on eyewear, gloves and change clothes,” she said.

I have pets. How can I protect them?

As irritating as smoke can be for people, it can cause health problems for your pets too.

Animals with cardiovascular or respiratory disease are especially at risk from smoke and should be closely watched during all periods of poor air quality, according to the American Veterinary Medical Assn.

Experts share the following information to keep your beloved animals safe during a poor or unhealthy air quality event:

• Keep pets indoors as much as possible, and keep your windows shut.
• Smoke is especially tough on your pet birds. Keep them inside when smoke is present.
• Let dogs and cats outside only for brief bathroom breaks if air quality alerts are in effect.
• Avoid intense outdoor exercise during periods of poor air quality. Exercise pets when dust and smoke have settled.

When can I stop wearing a mask and safely open my windows?

In regards to the current windblown advisory, experts advise you check for updates from local officials and follow their safety guidance.

How can I check the air quality in my area?

Even though windblown ash particles may be too large to be detected by air quality instrumentation and officials warn it will not influence Air Quality Index levels, you should still keep an eye on the air quality in your area.

When you are looking at the air quality reading, keep in mind the harmful particles that are not being recorded.

You can do so with the following tools:

• AirNow, the website and the app, created by the U.S. Environmental Protection Agency includes information from its permanent air quality monitors as well as temporary air quality monitors that will be put in place in incidents like this. It has an updated “Fire and Smoke” map, or you can enter your ZIP Code and check the air in your community.
• Purple Air is a company that helps monitor air quality by selling easy-to-install sensors with real-time data on various particulate matter levels. Purple Air has a free online map with real-time air quality data.
• The South Coast Air Quality Management District issues advisories, guidance and warnings in regards to air quality impacts. It has a current hourly air quality index map and a dedicated webpage to news releases of such advisories.

All resources will provide a number for the air quality index. If it’s greater than 100, that is considered unhealthy for sensitive and at-risk groups. If it’s greater than 150, it is considered unhealthy for all people.

Where can I find free N95 masks in Los Angeles County?

Here is a list of locations where you can pick up free N95 masks.

This list will be updated as more organizations, local agencies and others post their offerings.

• L.A. Care Health community resource centers. There is an extended list of locations and contact information online.
• All Los Angeles Public Library branches. The branches will be offering free masks while supplies last. Check online for branch address and hours; it’s encouraged you call ahead to check on supply inventory.
• Los Angeles city recreation and senior centers, aquatic facilities, golf courses, museums, and the Cabrillo Marine Aquarium will all be providing free masks. A complete list of locations and contact information is online.