Are N95 Masks Useful for Wildfire Smoke?


Good morning. So far in August, California has been hit hard by fires, record high temperatures and power blackouts, all amid a pandemic. One reader asked how residents with respiratory diseases are doing well.

Evan Underwood, who suffers from asthma, migraines and heat sensitivity, has been quarantined for months at his home in San Ramon. And now, with wildfires over Northern California, if the air quality index – which measures the pollution level – goes above 100, even after a few minutes of going outside, an asthma attack and migraine trigger that would last a whole day would last. His plan is to hunt at home until the fire season is over, as long as he does not lose power or be forced to evacuate.

For our series that answers readers’ questions about life during the pandemic, Mr. Underwood asked us about how inhaling smoke affects people at high risk for severe Covid-19, such as himself, and if they are more vulnerable to major disease. “When our whole region is bathed in smoke, when so many people still have damaged lungs, the virus is still endemic and people are going back to work, that can not be good, can it?” he wrote.

As my colleagues have reported, Covid-19 and smoke are a dangerous combination, as both affect the respiratory system, making those exposed to the virus more vulnerable.

Polluted air can also weaken the immune system of healthy people, making them more susceptible to diseases like Covid-19, according to experts from the Washington State Department of Health.

And studies have shown that in areas with poor air quality, people die more often when they contract the virus.

[Read the latest updates on the wildfires burning across California.]

“We know that people with asthma or chronic obstructive pulmonary disease are at a higher risk for both getting Covid-19 and have more severe symptoms when they become infected,” said Dr. Jeanne A. Noble, a physician for emergency medicine and the director of the response to Covid-19 at the emergency department of UCSF Medical Center. “Adding smoke inhalation into the mix will further increase everyone’s vulnerability to Covid-19, but especially to people with respiratory problems.”

Dr. Noble said she could see smoke rising above the city as she rode across the San Francisco-Oakland Bay Bridge Wednesday night to work. Since March, the emergency department at UCSF Hospital has been using open tents to properly care for patients while they wait to see. The fumes are likely to render them unusable.

“We strongly encourage everyone to take things in stride. It’s just so much safer. And now we can not, ‘she said. “It’s essentially when winter comes early.”

In addition, said Dr. Noble that their department is likely to be busier because there is always an uptick in respiratory cases during power outages of people who rely on electrically powered CPAP machines for breathing as nebulizers for medication management. Heat is also a trigger for asthma and emphysema, she said.

For people who are infected with Covid-19 and have suffering effects, said Dr. Michael Daignault, an emergency room physician at Providence Saint Joseph Medical Center in Burbank, said that since Covid-19 is a multi-systemic inflammatory disease, significant smoke exposure and inhalation, along with an underlying respiratory disease, may increase symptoms.

“I think this depends on the primary symptoms a patient had with Covid-19 and their underlying medical problems,” he said.

In previous years, people have used N95 masks as respirators to protect themselves from inhaling dangerous particles caused by fire smoke.

But Allison Thomas, a reader in Butte County, asked us: “There are no N95 masks available for the general public to use. What will we use when the wildfires start? ”

Like everything these days, the pandemic has complicated things. Both the Centers for Disease Control and Prevention and state public health officials are telling people to keep N95 masks for workers in front of the pandemic.

The California Department of Public Health states on its website:Do not buy N95 respirator masks for personal use. They are part of PPE needed by medical professionals. ”

Dr. Noble warns against using N95 masks with exhalation valves. Although they are effective at filtering particles of smoke, the valves allow the wearer’s breath to escape the mask, thus posing a risk of Covid-19 spreading. If the mask contains an exhalation valve, she said you should wear a surgical mask over it.

If you feel the effects of smoke, you should first try other means of reducing exposure.

In its Fire Smoke Manual, the Environmental Protection Agency advised, “Respirators should only be used after other, more effective methods of reducing exposure have been implemented, including staying indoors, reducing activity, and using HEPA indoor air purifiers to reduce general exposure to smoke. . ”

[What to know about buying an air purifier to clear wildfire smoke.]

If you can not reduce your exposure in other ways, experts say that N95 or N100 masks will work to filter fine particles. But keep in mind that respirators are not approved for infants and young children and may not work on people with beards.

For people with shortness of breath, said Dr. Daignault to make sure you have enough medication in advance and use breathing aids, such as albuterol, as needed and seek medical attention when things get upset.

Dr. Noble said: “I think people really need to wait and see about air quality.” She recommends checking the EPA’s interactive map for updates. ‘As many people are accustomed to following Covid-19 numbers to see when their primary school may reopen or when their province comes off the watchlist, I think people should now get into the habit of airing to check quality index. ”

Have a question about how the pandemic is changing daily life in California? Click here to submit.


Read our ongoing coverage of California wildfires and see where the fires are currently burning. [Latest Updates][Map of Wildfires]

  • An astonishing lack of planning, poor record keeping and weird bad luck left California short of electricity in a heat wave. Power plants with the ability to produce about 15 percent of the electricity on California’s grid were reported offline when temperatures rose last Friday. [The New York Times]

  • Hours before Uber and Lyft were due to discontinue riding dog services throughout California in response to a judge’s ruling, an appeals court granted them a temporary reprieve, allowing them to continue working while the court raises their appeal. [The New York Times]

  • Gavin Newsom canceled a scheduled appearance at the Democratic National Convention on Thursday as fires spread across California, instead sending in a cell phone video. [The Sacramento Bee]

  • Since she first ran for attorney general in California a decade ago, Kamala Harris has forged close ties with the tech sector. [The New York Times]

  • U.S. Postal Service workers in California reported chaotic conditions at postal facilities, including packages of rotting food, dead animals, and missing or padlocked mail sorters. [Los Angeles Times]

  • Two suspects have been arrested in connection with a hate crime against a group of transgender women in Hollywood this week. [Los Angeles Times]

  • After World War II, thousands of Japanese-Americans returned to the West Coast from Internet camps with nowhere to live. Poverty, restrictive housing conventions and rational prejudice allowed many homes to seek out where they could. [The New York Times]

  • The Criterion Collection, a highly prestigious film archive, has largely excluded Black Americans from its collection.. Only four films to be seen in the collection feature African-American directors. [The New York Times]


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Jill Cowan grew up in Orange County, went to school at UC Berkeley and has reported all over the state, including the Bay Area, Bakersfield and Los Angeles – but she always wants to see more. Follow here or on Twitter, @jillcowan.

California Today is edited by Julie Bloom, who grew up in Los Angeles and graduated from UC Berkeley.