Expert: Decreasing future COVID-19 spread indoors

With more coronavirus variants emerging in more places, the U.S. is focused on how we should be adjusting our social distancing efforts, mask wearing and use of indoor space.

Dr. Joseph Allen, associate professor and director of the Healthy Buildings program at Harvard University’s T.H. Chan School of Public Health, said even though it seems that coronavirus spikes from holiday gatherings have begun to ease, the newly discovered variants are certainly more transmissible and therefore more dangerous.

“If it proceeds the way we expect it will, based on what we’ve seen in other countries, these new highly transmissible strains should be the dominant strain in the coming weeks,” Allen said. “And what that means for the average person is that you really need to double down on the set of controls that we know work to help reduce risk.”

Dr. Allen said that, while it is not always possible to increase the amount of space between people while indoors, as in at grocery stores, it is highly important to increase the amount of ventilation in such buildings, and to wear high-er quality masks.

“If you’re out for a walk with a friend or at the park, I don’t think you need an N95,” Allen said. “But if you’re spending all day indoors, you’re an essential worker or a waiter or waitress at a restaurant, you’re going to want one of these better masks.”

Dr. Allen said an alternative to wearing an N95 mask would be a KF94, which is reportedly 94 percent effective.

“If you want good protection right now, today, with common materials that are in disposal, and you’re not sure which better mask to buy, a double-masking approach can work,” Allen said. “And that is simply taking a blue surgical mask, which has good filtration but not so much good fit, and put a cloth mask on top of the surgical mask. That improves the fit. You do that, and you can approach the effectiveness of an N95.”

Allen said that, after putting on two masks, any virus particles would then have to travel through two filters, which means a decrease in the chances of contracting the virus.

He added that, unfortunately, a face shield over a cloth mask is not equivalent in prevention quality as an N95 mask.

Dr. Allen, who wrote a paper that looked into the coronavirus outbreak on a Diamond Princess cruise ship last year, said that going forward the cruise ship industry is among the challenges for transitioning the world back into a pre-pandemic state, as most cruise ships deal with ventilation concerns.

He added that in the future, cruise ships will need to follow very strict rules in order to safely function, including testing travelers before entering and while on the ships.

“I wouldn’t be surprised if in the not-so-distant future, to go on a cruise ship you have to show proof of vaccination and/or proof of a negative COVID test - either a PCR-based test or a rapid antigen test.”

Dr. Allen said that in the past, the way buildings and traveling vehicles (planes, ships) were not designed to help prevent the spread of disease, therefore making regular inspections necessary going forward.

“The hope is that what everyone is waking up to, and what will hopefully lead to a change going forward, is to stop designing at the bare minimum air quality standards and start building a resilient and healthy building standard,” Allen said.

Meanwhile, he said it is definitely possible to have safe school, office and household environments. But the obvious problem lies where people fail to follow proper health protocols.

KCBS Radio’s Ask An Expert segment airs each weekday at 9:20 a.m. PT. To submit a question, please email AskUs@kcbsradio.com.