Masks not perfect, but do help, says Tri-County Health chief

Tri-County's Douglas, data shed light on misconceptions

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His local public-health department has issued another mask-wearing mandate for two metro-Denver counties with nearly 1.2 million people. Even so, John Douglas doesn't hesitate to admit that masks aren't perfect in the fight against COVID-19.

“But, like vaccines, they work better when more people use them,” Douglas, executive director of the Tri-County Health Department, told Colorado Community Media.

“Because, like vaccines, they can both prevent the individual from getting infected or sick,” and also can prevent spread of the virus to others, Douglas said.

Tri-County Health serves Adams and Arapahoe counties, and provides certain public-health services in Douglas County.

Under a Nov. 22 Tri-County order, all people 2 and older in Adams and Arapahoe County must wear a face covering in all public indoor spaces. Authorities in Jefferson, Denver and Boulder counties have issued similar mandates.

With rates of new coronavirus cases reaching levels not seen since December of last year — and daily deaths among those with COVID-19 recently hitting numbers higher than they did during the first wave in spring 2020 — coronavirus hospitalizations in Colorado had for months been creeping up toward last December's peak. Colorado had 1,466 people hospitalized with confirmed COVID-19 as of Nov. 30, according to state data.

Colorado had the 10th-highest COVID-19 hospital demand in the United States as of early November, according to a Nov. 3 report by the Colorado School of Public Health.

But with the public hearing so many concerns about masks and mask effectiveness — and about vaccines — why wear a mask? Why get vaccinated when so many people already have been?

Colorado Community Media spoke to Douglas and reviewed other sources of information below to address those questions.

Like 'sand through a chain-link fence'

At a contentious public comment session in front of Arapahoe County's elected leaders after Tri-County Health issued its school mask order in August, a man offered an evocative picture of how he thought masks interact with the coronavirus.

“If you took a fist of sand and threw it through a chain-link fence, imagine how much of it would go through,” the man said during the meeting, noting how small the virus is.

A post on a popular social media page last year, focusing specifically on N95 masks, said: “COVID 19 virus particle size is 125 nanometers (0.125 microns); the range is 0.06 microns to .14 microns,” the post said, according to a USA Today fact-check report. “The N95 mask filters down to 0.3 microns. So, N95 masks block few, if any, virions (virus particles).”

A micron is one one-thousandth of a millimeter — it's also referred to as a micrometer.

But there's more to it than that. A COVID-19 virus particle exists on a tiny scale — around 0.1 microns in size — but it is always bonded to something larger, an expert told USA Today for the report. In other words, masks don't have to stop bare virus particles alone.

“There is never a naked virus floating in the air or released by people,” Linsey Marr, a professor of civil and environmental engineering at Virginia Tech who specializes in airborne transmission of viruses, told USA Today.

The virus attaches to water droplets or aerosols — really small droplets — that are generated by breathing, talking, coughing and so on. These consist of water, mucus protein and other biological material and are all larger than 1 micron, USA Today reported.

Those points were echoed in a research article published in the journal City and Environment Interactions and available online in May 2020, a piece that also suggested the use of masks indoors and improving ventilation to combat COVID-19.

Douglas, the local health chief, has said masks have been shown to be “50-70% effective.” The federal Centers for Disease Control and Prevention's website says: “Multi-layer cloth masks can both block up to 50-70% of … fine droplets and particles and limit the forward spread of those that are not captured.”

Another speaker at that Arapahoe County commissioners' meeting in August, from Centennial, said: “If you want to wear a mask, wear it. If you don't, then don't. If your guys' mask works so well, why do I have to wear one? Why does my kid have to wear one?”

The issue arose again at a Nov. 22 Arapahoe commissioners' meeting, where Commissioner Nancy Sharpe said: “I do think there's a level of personal responsibility ... They should wear them if they want to wear them and if they need to wear them.”

Masks are primarily intended to reduce the emission of droplets toward others, an effect known as “source control,” as opposed to “wearer protection,” the CDC's website says.

But studies also demonstrate that cloth mask materials can also reduce wearers' exposure to infectious droplets through filtration, including filtration of fine droplets and particles less than 10 microns.

“The relationship between source control and wearer protection is likely complementary and possibly synergistic, so that individual benefit increases with increasing community mask use,” the website adds.

See the long list of studies the CDC cites about mask effectiveness and related topics near the bottom of that page.

“By the way, we often forget that this is (spreading) because a very large chunk — maybe 60% of COVID cases — (come from) people who are asymptomatic or presymptomatic,” Douglas said, using terms for people who have COVID-19 without symptoms or whose symptoms have yet to arise.

For a look at other mask data, see our previous story.

Because masks aren't a cure-all, physical distancing; meeting outdoors rather than indoors; avoiding large groups; and improving ventilation by opening windows or running heat, air conditioning, or an air purifier are all still important steps to take, the Colorado Department of Public Health and Environment reiterated on Nov. 24 ahead of holiday celebrations.

Masks in schools

State health officials have presented data showing that requiring kids to wear masks while in school is associated with lower rates of COVID-19, The Colorado Sun reported in September, citing comments from Rachel Herlihy, the Colorado state epidemiologist.

The state public-health department looked at age-adjusted case rates for kids in 48 school districts, split into two groups by whether the districts are requiring masks in schools, the Sun reported.

A recent CDC study looked at the impact of masking in schools on COVID-19 case rates among K-12 students across the United States. Counties without school mask requirements experienced larger increases in pediatric COVID-19 case rates after the start of school compared with counties that had school mask requirements, according to the Sept. 24 study.

While Douglas acknowledged it's difficult to say unequivocally that the masks made the difference, he's confident that the data back up that conclusion.

“What is notable in the data from CDPHE and even more so from the national study performed by CDC is that while rates were reasonably similar between districts that did and did not implement mandates going into the school year, they increased substantially more in the areas without mandates than in those that had them, which is highly consistent with a benefit of the mandate,” Douglas said.

Mental health concerns

Douglas previously responded to concerns among some parents that masks are making kids anxious or leading to other negative mental health outcomes.

Mental health concerns among young people are likely due to family life and routines being disrupted amid the pandemic, along with isolation and uncertainty, according to Douglas.

Speaking to Colorado Community Media, Douglas said younger kids “probably do lose a lot of emotional cues” such as smiles, frowns or teachers' lips moving.

“I don't disagree at all that from a learning perspective, there may be an impact, but the counter to that is that masks have ended up being (what) allows kids to stay (safe) in the classroom anyway,” Douglas said.

As opposed to school being remote, kids get more social interaction from being in a classroom, Douglas said.

“You've got better education outcomes (and) probably better social-emotional outcomes” in that case, Douglas said.

The text of Tri-County Health's initial mid-August school mask order also addressed the topic of mental health. It reads: “Children's Hospital Colorado clarified that mask wearing has not been linked to mental health problems in children or any other group and did not contribute to their declared 'state of emergency' for pediatric mental health.”

Elizabeth Whitehead, a spokesperson for Children's Hospital Colorado, confirmed the accuracy of that statement.

For more outside information on masks and mental health, see the “mental health” section of our previous story.

Physical health concerns

Another claim that came up during a Tri-County board of health meeting on Aug. 16: Masks problematically forcing a person to “rebreathe the carbon dioxide.”

Wearing a mask does produce a “small increase” in breathing resistance caused by the mask material filtering particles and any moisture that is trapped in the mask material, according to a commentary in the International Journal of Environmental Research and Public Health.

“One consistently documented negative impact of wearing a mask for a long period of time is an increase in the development of headaches in people with a history of headaches,” the September 2020 article says.

“In otherwise healthy individuals, wearing masks, even for an extended period of time, does not produce any clinically relevant changes in circulating O2 or CO2 concentrations, and does not seem to impact tidal volume or respiratory rate,” the article says.

Douglas pointed to real-world experience: health and hospital settings, where health care providers have been wearing masks for “decades if not longer.”

“There have been virtually no detected impacts on acute health, long term health (or) job performance,” Douglas said.

Why more vaccinations?

The speaker at the Arapahoe County commissioners' meeting in August from Centennial also asked: “If your vaccine works so well and you believe in it so much, why do I have to wear a mask? Why do I have to get a vaccine?”

Douglas, speaking to CCM, brought up the example of compelling people by law to wear seatbelts.

“We've made the decision that somebody dying in a car accident is a bad enough societal impact that something pretty minor … seatbelt wearing, is something we endorse and use,” Douglas said. He added: “Most of the time, a law like that is purely designed to protect the person using the preventive measure.”

He noted that the chances of the virus spreading — and the chances of more-dangerous variants developing — are reduced the more people get the vaccine.

“We're in this national, if not global, lifeboat together because we share a contagion that can spread globally really quickly, certainly quickly nationally,” Douglas said.

Some people who are fully vaccinated will still get COVID-19, according to the CDC. An infection of a fully vaccinated person is referred to as a “vaccine breakthrough infection,” the CDC's website says. Like other vaccines, COVID-19 vaccines are not 100% effective.

That's part of why stopping the virus's spread on a societal level is important — and it's partly why mask wearing is still being urged.

Even when fully vaccinated people develop symptoms, they tend to be less severe symptoms than in unvaccinated people. This means they are much less likely to be hospitalized or die than people who are not vaccinated, the CDC's website says.

Herd immunity

Some may be wondering when enough people will be vaccinated for life to begin returning to some semblance of normal.

At one point, it was thought that “herd immunity” — a term for when enough people become immune that the spread of a disease becomes unlikely — could happen when around 70% to 80% of people attain immunity to COVID-19. (See more on how that works in the sidebar in our previous story.)

But there is uncertainty regarding the true herd immunity threshold.

What's more, the delta coronavirus variant is more transmissible, a development that changes the percentage needed for herd immunity, according to an article from the American Medical Association.

“Herd immunity is a helpful concept but often difficult to operationalize and hang your hat on,” Douglas said. “The estimate went up because delta is over twice as contagious as the original strain. Eighty to 90% of persons in the population being immune is the best estimate at this point, but it would go higher if an even more contagious variant emerged.”

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