Wednesday, July 28

Five reasons you may still want to wear a mask – San Francisco Chronicle

With California lifting nearly all COVID-19 pandemic restrictions, fully vaccinated people no longer need to wear masks in most public settings — but health experts say there are some good reasons for continuing to do so.

It is no coincidence that this year’s flu season was the mildest on record. Masks cut the spread of infectious respiratory particles, including those carrying influenza.

“The prevention benefit of masking is derived from the combination of source control and wearer protection,” according to the federal Centers for Disease Control and Prevention. Translation: Masks not only protect you from others, but others from you when you’re sick.

Asian countries embraced wearing masks to prevent the spread of infections after the SARS outbreak in 2003, but Americans have yet to catch on. With influenza vaccines typically showing only 40% to 60% efficacy against seasonal viruses, it might be time to change that.

“What you’re talking about is influenza that makes people have to stay home from school, stay home from work,” said Peter Chin-Hong, an infectious disease expert at UCSF. “If there’s a way to not get influenza by wearing a mask, you can do that to protect yourself and others. It’s a medical intervention.”

Shielding from thousands of people

An arena full of people is one of the few situations in which California still requires people either to be vaccinated or have a recent negative COVID test — but compliance is on the honor system. Unless you have boundless faith in your fellow humanity in a state where nearly half the residents remain unvaccinated and the worrisome delta variant is starting to spread, maybe mask up.

“Unvaccinated folks, or people who are in subgroups like kids or immuno-compromised individuals, or even people who got vaccinated outside of the country, may want to wear a mask in those settings,” Chin-Hong said.

Those with additional risk factors or children under 12, who are not yet eligible to receive their shots, may also consider wearing masks in crowded settings.

“If we are at some wheezy old theater that’s completely packed with people who look like they might not be vaccinated, that might cause me to put on a mask,” said Dr. George Rutherford, an infectious disease expert with UCSF who is over 65. “But I think it would be a pretty unusual circumstance.”

Less sneezing during allergy season

Masks not only help curb the spread of the coronavirus, but scientists found that they also help limit symptoms associated with seasonal allergies, according to a study published last year by the National Institutes of Health.

“A regular surgical mask is going to help protect the wearer from exposure to allergens,” said Chin-Hong, who did not take part in the study.

Standard surgical masks can filter out particles larger than 3 micrometers, while an N95 mask can block particles as small as 0.04 micrometers, the researchers said.

Both are effective in reducing inhalation of airborne allergens that can cause itchy eyes and stuffy noses, such as pollen (typically between 10 and 100 micrometers in size), fungal spores (between 2 and 50 micrometers) and house dust (between 10 and 40 micrometers).

Protection from smoke

Bay Area residents have grown familiar with the smoky skies and unbreathable air that signals the California fire season. While experts recommend staying inside a building with clear air, N95 masks may provide some relief for people who have no choice but to be outside for long periods.

But they come with some caveats: The masks need to be fit to the individual, with no gaps to let in outside air. Children should never wear them because they’re not designed to fit their faces. No one should wear them while doing intense activities — in other words, putting on an N95 mask does not make it OK to go outside for a jog when the air is unsafe.

Feel less anxious, or just warmer

After a year of believing that potential deadly hazards are lurking in the air, some people may have a hard time giving up masks. But there are more practical reasons for retaining face coverings, even if you are fully vaccinated.

“We don’t want to shame people for wearing a mask,” Chin-Hong said. “There are psychological and personal reasons, like wanting to be incognito or keeping you warm from a cold San Francisco wind.”

Over the past year, people have discovered the many conveniences that come from wearing a mask — from avoiding unnecessary conversation with strangers to using them as a fashion accessory.

“There’s no real con,” Chin-Hong said. “Nobody dies from wearing a mask. You can still breathe through them. If you don’t want to wear a mask, it’s fine. If you want to wear a mask, wear a mask. It shouldn’t be a political statement.”

Aidin Vaziri is a San Francisco Chronicle staff writer. Email:

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