The science behind wearing a mask

TALLAHASSEE, Fla. (WCTV) - Plenty has been said about putting on a mask since the COVID-19 pandemic began. There is plenty of truth, but also no shortage of misinformation and disinformation.

FSU Medical School Assistant Professor and practicing pediatrician Dr. Ramiz Kseri spoke with WCTV in late August for nearly 45 minutes on topics from how the virus is spread, how scientists know the virus is spread, and fact checking some of misconceptions floating in the wild.

How the virus is spread

SARS-CoV-2, the virus that causes COVID-19, is spread by very small droplets from the mouth and nose.

“Every time you cough, every time you sneeze, or just exert yourself, you have a strong grunt, you might produce some of those very, very small droplets and that’s how the infection can spread from one person to the next,” Kseri said.

There was uncertainty in the beginning of the pandemic about how it was spread, according to Kseri. The unknown was one of the reasons why masks were not initially recommended to limit the spread.

“In time, we learned a little bit more about [the virus],” he said. “That’s when masks made more sense [to wear masks].”

How masks limit the spread of the virus

The masks act as a physical barrier between the face and the surrounding environment.

“Having a barrier like a mask is how you are able to prevent that spread from one person to the next,” Kseri said.

Masks limit the spread of the droplets that would contain the virus and spread to other hosts (humans).

Is there a mask that’s better than another? What about two masks?

Different types of material can have an impact on the effectiveness of the mask, assuming they are being worn correctly.

“I’ve seen some people wear mesh masks,” Kseri said. “Well, if you have giant holes in your mask, those are definitely not going to stop droplets.”

He said that cloth masks are sufficient with providing protection to limiting the spread and contracting the strain of coronavirus. There is also research, Kseri said, that claims that wearing two masks would be better than one.

“More barrier creates more protection,” he said.

Kseri is likely referring to a study released by the CDC earlier in 2021. The researchers placed two masks on a “dummy” to simulate coughing. They also tested out a single mask and “knotting and tucking the medical procedure mask.” Researchers found that double masking blocked 85% of the cough particles compared to 51% with just wearing one mask. There were caveats, according to the study’s authors, which noted children or those with beards interfering with the fit, and different materials may also be used compared to what was used in the experiment.

How do scientists and physicians know that masks work

Physicians have known the effectiveness on spreading disease for a while, according to Kseri.

“Working on the pediatric ward, there are tens of viruses from rhino virus to RSV to all of these things that you hear about,” he said. “One of the things we do in training is that every time a child is diagnosed with one of those viruses, they end up getting a droplet precaution on their room. Everyone that is walking into that room appropriately gowns, appropriately puts masks - whatever the kind of precautions are. We know from practice that that works.”

As for SARS-CoV-2, there are a few studies that have looked into the effectiveness by either observation or experimental (e.g. the aforementioned CDC study).

One example is a study that looked into infections, hospitalizations and deaths in Kansas counties that had and didn’t have mask mandates. By late in the study period, cases were nearly two times higher in no-mask counties according to research published in the Journal of the American Medical Association. Hospitalizations and deaths were 1.4 and 1.8 times higher in no-mask counties, respectively, late in the trial period.

Another study looked at all 50 states and found that there was a statistically significant decrease in new cases up to 40 days after the start of mask mandates.

There are critics that do question the effectiveness of masks. A common and recent study cited is one from Brown University. The study, not-yet peer reviewed as of this writing and with an economics professor as the lead author, did say that it was “important to note that this does not imply masks are ineffective, as these results focus only on masking in schools and do not take community behavior into consideration.”

Are there psychological concerns about children wearing masks?

“I don’t know of any literature that’s based on good research” that reflects psychological harm done to children from wearing masks, Kseri said.

“One of the things I’ve seen quite a bit of in the past six to nine months was kids going back to school [with] a lot of obesity, a lot of mental health issues partly because of isolation and feeling they are not integrated socially with their peers,” he said. “Younger children who have not been able to go to kindergarten or interact with other children. Language skills. All of these things - those are long-lasting effects.”

“The ability of children to be physically back in school, interacting with their peers, being physically active, being able to kind of participate in sports, that has such a great benefit compared to whatever minute risk there is in wearing masks,” Kseri continued.

Do masks increase carbon dioxide levels?

Another common argument in recent days has been that masks allegedly cause children to cause higher carbon dioxide levels, or cause difficulty breathing.

“I would love to see those data,” he said. “Unless a child an underlying condition, I don’t see how [that’s the case]. I haven’t seen from the CDC any strong data to indicate that it’s even a remote possibility.”

“The discomfort of wearing them, I promise you, is a lot better than the consequence of getting COVID,” he said.

Are masks 100% effective?

“It is not,” Kseri said answering the question on whether or not masks are 100% effective in spreading the virus that causes COVID-19.

“I don’t think there’s ever been a claim by the CDC or any kind of medical entity to say it works 100 percent,” he said. “But it’s all about risk reduction.”

Wearing masks properly, social distancing, and getting vaccinated (if eligible) are tasks that, Kseri said, will have a cumulative drop in contracting and spreading the novel strain of coronavirus.

“If all of us, as a community, begin to truly engage in all of those steps, we will be able to get over this,” he said. “But it requires active participation, again, on everyone’s behalf and especially parents of children who are younger than 12 and are unable to get vaccinated.”

What is the “gold standard” of scientific studies?

With respect to the effectiveness of proper mask wearing, studies have either looked at cases as a whole compared to local mask mandates, small-scale case studies, and environmental studies. But the “gold standard” of research studies is known as a Randomized Control Trial (RCT).

That type of experiment is “study design that randomly assigns participants into an experimental group or a control group,” according to The George Washington University.

But, with mask wearing, there are a least two problems with an RCT study and COVID-19 according to Kseri.

“Part of doing a research study like that would be a little bit challenging because then it’s obvious in the face,” he said. “It’s not like you can give placebo to someone versus another. You’re either wearing a mask [or you are not]. So, you relate kind of bias within that because you can visibly see the intervention.”

There are also ethical concerns: Bringing the potential of not only getting someone sick, but also spreading the illness to others.

“It would also be unethical for us to kind of put people at risk knowing that masks work and just ask them to be the placebo of the experiment,” Kseri said. “At the end of the day, especially for a physician, our job is do no harm.”

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