With COVID risk elevated in Bay Area, should you upgrade or double your mask? – San Francisco Chronicle

The Bay Area’s worst coronavirus surge yet is finally starting to ease, but in its wake, pandemic risks are higher than before.

And as the region starts to reopen, experts say it’s time to double down on safety measures — which may include upgrading or even doubling your mask for maximum protection.

Such measures are important, they say, because case levels remain high, California’s vaccine rollout has been rocky, and a number of new variants are popping up in the state and around the country. One from the United Kingdom is more infectious and could become the dominant strain by March. One found and being studied in the Bay Area, and others from Brazil and South Africa, could possibly evade antibodies created by the new coronavirus vaccines or maybe even reinfect people a second time, experts say.

“We are at an urgent period of transmission because … we are in our third and worst surge of the pandemic, and our vaccine rollout is still not rapid enough,” said Monica Gandhi, an infectious disease specialist at UCSF. “It is an incredibly important time to do everything we can to tamp down transmission.”

Experts are urging the public to ramp up the familiar safety measures of social distancing, hand washing and wearing masks. With more virus transmission everywhere and the new variants possibly leading to higher rates of infection, vigilance is more important than ever.

In particular, experts are offering new recommendations on whether your masking is up to snuff.

Several European countries, including Germany and Austria, are now requiring everyone to wear surgical or N95 grade masks. Some Asian countries are mailing high-quality masks to their residents.

Gandhi worked with Linsey Marr, an expert on airborne transmission of viruses and a professor of civil engineering at Virginia Tech, on a scientific article about the importance of and science behind face masks. They offer advice on what types of face masks offer the best protection.

What’s the best face mask out there?

Gandhi said N95 masks are the gold standard, but it’s still challenging for the general population to obtain them because they are in shorter supply, they have to be fit-tested, and can be uncomfortable because they are so snug.

Mark Holton wears two masks in Wyoming County, Pa.

Mark Holton wears two masks in Wyoming County, Pa.

Mark Moran / Associated Press

Can I get close to an N95 mask? What about cloth and surgical masks?

The article by Gandhi and Marr cites a study conducted by Marr and some graduate students that tested the effectiveness of 10 different masks. Based on the findings, they recommend a high-quality surgical mask or cloth mask with at least two layers with high thread count for basic protection.

Who should be double-masking?

During an appearance this week on NBC’s “Today Show,” top U.S. infectious disease expert Dr. Anthony Fauci said that wearing two masks “just makes common sense that it likely would be more effective” at preventing droplets from getting through.

But Gandhi said she doesn’t think it’s necessary for everyone to wear two masks all the time, and that “buy-in of masks in this country is still uneven and complicated.” Instead, her recommendations focus on certain individuals and situations:

• Medically vulnerable and older individuals.

• Individuals who work in crowded indoor conditions such as meat processing plants and restaurant kitchens.

• Those in indoor environments with others not in their household, in an area of high transmission. Most of California is in a period of high transmission right now, including the Bay Area.

When looking at the trio of masking, distancing and ventilation, one can diminish the other, Gandhi said. So if you are wearing a single mask but are outdoors, that makes up for the mask. If you are inside and double-mask, that makes up for lack of ventilation.

But if you’re particularly concerned, she said, do what makes you feel most comfortable.

“Anyone who feels more worried about the virus, it’s a great thing to do,” she said.

How can I get the best protection?

According to the study cited by Gandhi, those with concerns have several options for maximum protection:

A tight-fitting cloth mask over a surgical mask, which acts like a filter. Surgical masks tend to fit looser than other masks, so this would improve fit and add protection.

A three-layer, tightly woven cloth mask with a filter pocket. Vacuum or HEPA filters can be used, and many companies now sell affordable, precut filter inserts for masks.

The study found that if the masks fit well, “these combinations should produce an overall efficiency of >90% for particles 1 mm and larger, which corresponds to the size of respiratory aerosols that we think are most important in mediating transmission of COVID-19,” according to the article.

According to the CDC, studies have shown that multilayer cloth masks can block 50% to 70% of large and fine droplets. Masks with multiple layers of tightly woven cloth performed better than single layer masks, filtering almost 50% of fine particles. Surgical masks are 60% to 70% effective at protecting others, and 50% effective at protecting the wearer, according to studies.

Gandhi stressed that users should pair a surgical mask with a cloth mask because a surgical mask blocks viruses electrostatically, while a cloth mask blocks them physically, so layering them uses two different mechanisms. The same goes with the filters and the cloth masks. And when looking for surgical masks, make sure they are made of polypropylene.

Is layering more than two masks even better?

There’s no need to go overboard. Layering more than two masks has “zero utility,” Gandhi said, and the more you pile on, the harder it is to breathe.

What about KN95 masks?

Other N95 versions are offered, including the KN95 from China and the KF94 from South Korea. Gandhi said they are exactly the same as N95 masks but don’t fit as tightly, so people who want more protection should put a cloth mask over them.

Kellie Hwang is a San Francisco Chronicle staff writer. Email: kellie.hwang@sfchronicle.com