Mask Wearing Can Do Harm
For those who claim to “follow the science,” here is a lesson on the difficulty of proving the benefit of a blanket policy.
The leading health experts the public trust in have been almost uniformly advocating wearing a mask during the current pandemic. Along with social distancing, hand washing and testing, it’s one of the “common sense” practices everyone is told to abide by to prevent the spread of COVID-19. Experts from the CDC and NIH appear on TV repeating the advice. Vice President Biden, boasting of his intent to “follow the science,” has been threatening a prolonged national mask mandate should he be inaugurated president on January 20, 2021. Along sidewalks and in the few stores remaining open, the compliant wear their masks, some making fashion statements with them, while some rebellious holdouts flout the order, sometimes garnering disapproving glances from the cooperators.
New research from the University of Massachusetts casts doubt on the adequacy of masks for protection from the pandemic. Like many things in health science, it’s not always clear cut; it depends on various factors. Measures of effectiveness vary along a range of percentages.
Their paper illustrates the difference between science as it is publicized and science as it really is. As a summary of the new research shows, masks matter – but many variables make the advice more complicated than people realize, when particle sizes, fabrics, and cleanliness are considered. Sometimes, in fact, masks can do more harm than good!
The mask matters: How masks affect airflow, protection effectiveness (American Institute of Physics, via Phys.org). Researchers considered the physics of fluids and the sizes of particles in a variety of masks and wearers. “Even though it has been widely known that wearing a face mask will help mitigate the community spread of COVID-19,” they say, “less is known regarding the specific effectiveness of masks in reducing the viral load in the respiratory tracts of those wearing them.” How is that possible after ten months of a global pandemic being studied by scientists around the world?
“It is natural to think that wearing a mask, no matter new or old, should always be better than nothing. Our results show that this belief is only true for particles larger than 5 micrometers, but not for fine particles smaller than 2.5 micrometers,” said author Jinxiang Xi.
The researchers found that wearing a mask with low (less than 30%) filtration efficiency can be worse than without.
Don’t Just Follow the Crowd; Think and Ask Questions
There are too many variables for a blanket mandate. For instance, when governors and mayors order their citizens to “wear a mask,” what mask is acceptable? Masks vary widely in material strength and permeability. Is a cloth mask better than a paper mask? Do people need N95-grade masks or surgical masks? How about face shields and bandanas? Many people undoubtedly wear the same mask every day, keeping it on a dirty car seat, in a dirty purse or pocket, or on a dirty desk or counter. That risks breathing in germs from those locations and concentrating them in the throat and lungs, weakening the immune system from its ability to fight the very culprit everyone wants to avoid, the SARS-coV-2. Those viruses, with diameters about 0.1 micrometers, can pass through most masks like a mosquito flying through a chain link fence.
Performing experiments with a variety of masks and their ability to stop penetration of various particle sizes, the researchers followed how droplets and particles became deposited on the faces of mask wearers and continued into the airway and lungs. By decreasing the airflow, the mask might even become more effective at causing harmful particles to remain on the face and get into the nose and mouth.
The model showed a mask changes the airflow around the face, so that instead of air entering the mouth and nose through specific paths, air enters the mouth and nose through the entire mask surface but at lower speeds.
The lower speed near the face favors the inhalation of aerosols into the nose, so even though masks filter out certain numbers of particles, more particles escaping mask filtration can enter the respiratory tract.
They found the filtration efficiency of the three-layer surgical mask can vary from 65%, if new, to 25%, when used, so wearing a 65% mask properly will provide good protection, but wearing a 25% filtration mask can be worse than not wearing one at all.
The paper is open-access,1 so individuals can see the details and share them with government officials who are prone to order mask wearing without adequate scientific knowledge. There have been cases where citizens have been cited for not having a mask on when alone at home, or walking alone on a beach or in a forest, or out on the lake alone in a boat. The blanket order becomes its own justification for classifying people into cooperators and lawbreakers. It becomes a method for power-hungry leaders to flex their authority and gloat at what they can make people do.
“We hope public health authorities strengthen the current preventative measures to curb COVID-19 transmission, like choosing a more effective mask, wearing it properly for the highest protection, and avoid using an excessively used or expired surgical mask,” said Xi.
A take-home point is that blanket policies that claim to “follow the science” can actually be anti-science when the details are considered.
- Jinjiang Xi et al., “Effects of mask-wearing on the inhalability and deposition of airborne SARS-CoV-2 aerosols in human upper airway,” Physics of Fluids (American Institute of Physics), 32, 123312 (2020); https://doi.org/10.1063/5.0034580. One researcher is from California Baptist University; the other two are from the University of Massachusetts at Lowell.
Masks clearly can help in some situations, such as in operating rooms. This commentary does not demean the use of masks, or recommend flouting the orders, but uses this research as an illustration of insufficient rigor in the understanding of science in general by many in the public and government.
When given a blanket order such as “wear a mask,” smart citizens should ask a number of questions: What kind of mask? Under what conditions? For how long at a time? How do you know it helps? How do you know it doesn’t cause more harm than good? Can constricting the airways hinder natural breathing for good health? Can masks concentrate pathogens on the face? Is it healthy to keep breathing in the same germs? How often does a mask need to be cleaned? Where is the research to show it can stop viruses? How effective is mask wearing compared to other mitigations, like social distancing? Is mask wearing equally effective for all age groups and for both sexes? Do masks need to be worn outdoors? Is mask wearing for the wearer’s benefit, for others’ benefit, or both, or neither? Where is the evidence that mask wearing has stopped the spread of COVID-19? Was it a controlled experiment? If not, how can you trust it?
Few are the people who understand the intricacies and uncertainties in scientific research in order to ask such questions. Even in this paper, the authors left some questions unaddressed, such as the influence of mask shape on airflow, and the fit of the mask to the face.
It is pathetic that this paper is coming out after almost 10 months of non-stop advice to “wear a mask.” Will the leaders of “consensus science” (an oxymoron) be convinced to backtrack and confess to the public that their science was flawed? Will WHO, the CDC and NIH change their public recommendations based on this new research? Don’t count on it. Groupthink is a pervasive human trait.
We do not advise putting on a Lone-Ranger mask over the eyes when being virtue-shamed by a lemming shouting, “You should be wearing a mask!”