COVID-19 and the Mask


Wearing a mask by general public in private and social life during the COVID-19 epidemic has different approaches. This post presents my personal opinion which has been gradually formed by emerging facts and deeper understanding of the current epidemiological situation. However, unfortunately, we have minimal scientifically supported data and maximal fear-mongering statements. The main goal of this post is in presenting rationality of mask wearing in private life.

This post violates the rules of the short size of a Blog’s entry. The subject requires a comprehensive presentation because the mask wearing issue became a civil life event.

The readers, who are in haste to conclusions, can omit some pages. Many details reflect some of my literature research work which support my opinion. The most available sources are related to influenzas and prior coronavirus epidemics. World Health Organization (WHO) separated COVID-19 from other coronaviruses outbreaks. Without going in the politically charged viruses classification terminology, SARS-CoV-2 virus is the closest relative of SARS-CoV, first cousin. For the wearing a mask issue, these viruses discharge pattern is the same.

Only in rare occasions, some references are provided, because this post is not a scientific study. It is rather an opinion on the background of pathophysiology, environment physics, my experience as a laboratory practitioner, and… some common sense.

Elective masks’ classification

Surgical operational mask

The surgical mask serves to protect the operation field and the operative room from infectious contamination. The use of this kind of masks is undisputable.  Now even dental hygienists use them though also for self-protection.

Mask for an ill person

Wearing a mask by an ill person with symptoms of potentially infectious discharge (or even without) is in the same line, although more nuanced, as a surgical mask. Even positively tested, as socially considerate citizens, might be required to wear one, if they would not be in a quarantine confinement. This issue along with rationality of testing itself requires special discussion.

Professional PPE mask

Masks, as part of Personal Protective Equipment (PPE) predominately in anatomic pathology laboratory, were discussed in previous posts. OSHA regulation are the bottom line with some variant depending on the local implementation. The principles can be extrapolated to other areas in medical field with some correction of the assigned procedures, especially during the care for COVID-19 patients in the acute stage of the disease.

Mask as part of civilian life, a “street mask”

The current post is going to touch on the topic of wearing a mask which can loosely be called a private life mask, or elected mask, or civilian mask, or casual mask, or a “street mask” or any better name during the COVID-19 epidemic.

Since April 12th, wearing a mask outdoors is mandatory in Israel. Although there some exceptions for certain categories of situations, such a ruling for the entire country requires a close look. Is not unjustified fear or other, including political considerations, influence such decision? Is there a reliable research support?

There is a no-love triangle in the epidemic outbreak where the mask, the object of this post, has been caught in the middle. The Diagram presents the participants which cannot be separate in real live, but need to be discussed separately for the sake of a comprehensive approach. The virus, the culprit, being on the top of the triangle in the ambient environment is infecting individuals. Their encounter creates an epidemiological “crime scene”.

Virus: the intruder, the culprit

Supposedly, we have reliable information about SARS-CoV-2 virus (or COVID-19 virus), when human-to-human transmission of the SARS-CoV-2 in Wuhan, China, began in December 2019. The name SARS-CoV-2 virus was selected by International Committee on Taxonomy of Viruses due to the nucleotide sequence similar to SARS-CoV which caused the 2003 SARS epidemic.

SARS-CoV-2 virus is an enveloped particle containing single-stranded RNA associated with a nucleoprotein within a shell of matrix protein. The envelope bears projections which glycoproteins are responsible for attachment to the host cell. After the virus enters the host cell and uncoats, the genome is transcribed and then translated. The mRNAs form a unique “nested set” by budding from host cell membranes.  This is a short description of the virus’s initial nefarious behavior in the infected area.

Person: the host, the victim

An incoming coronavirus needs to find epithelial cells to invade the host. It intrudes predominately into the respiratory tract. The intrinsic barrier on the mucosal surface of the respiratory epithelium provides the first line of defense against respiratory viruses. Mucus layers can effectively trap the virus before it can enter the host cells. Infected cells become vacuolated. Cell damage triggers the production of inflammatory mediators, which in turn increases nasal secretion and causes local inflammation and swelling. Mucociliary Clearance Apparatus (MCC) serves as a key mechanism for eliminating the intruders from the respiratory epithelial surface. If that protection fails, they move toward the larynx, where mucus containing the entrapped virus is swallowed or expectorated (Seasonality of Respiratory Viral Infections. Annual Review of Virology; 2020, 7:2.1–2.19).

This local reaction to the virus intrusion is relevant to the mask wearing topic. These responses stimulate sneezing and obstruct the airway, and raise the temperature of the mucosa or even the body’s temperature. Relationship between temperature, humidity, and COVID-19 virus can increase host’s susceptibility to infections. Inhalation of cold dry air directly affects the upper airway mucosa, impairs mucociliary clearance, and increases mucin production, as well as potentially causing epithelial damage.

The subject of this post is the protective mask. It is important to visualize what happens when the virus is leaving the infected nasopharyngeal and orotracheal areas, through sneezing, coughing, even speaking, and perhaps just in minimal skin contact in form of snot, sputum, saliva, and skin cornea. The virus is not “naked” (it is impossible), but now it is coated by mucus and large and small droplets of water that depends very much on air humidity. Components of the mucus are 93– 97% w/w water.

Epidemiological crime scene encounter

Respiratory virus infection can occur through:

 (a) direct contact,

 (b) droplet spray in shortrange transmission, or

 (c) aerosol in long-range transmission (airborne transmission).

Direct contact transmission occurs either indirectly through contact with infected (by virus) secretions or directly through physical touch between an infected individual and a susceptible person. Just common sense, it cannot be managed by mask or its absence.

Droplet spray in shortrange transmission can be prevented by a mask. This is a purpose of the mask as part of PPE. Droplet transmission requires the source of infectious to directly spray large droplets by coughing or sneezing onto mucous surfaces or eye conjunctiva of a susceptible person.

The overwhelming majority of person-to-person transmission happens indoors through discharge by an ill person through droplet spray in shortrange transmission. Wearing a mask by an ill person, besides apparent rationale of preventing the discharge of the virus, requires a closer look at scientific data which support this notion. The load of infections material, frequency of encounters, proximity from the individual with discharge, and other epidemiological details require scientifically reliable data.

A direct quote from an article: “In order for droplet transmission to occur infected and susceptible persons have to be in close contact (several tens of cm apart), of comparable height and the sneeze or cough has to be directed in the “right” direction. The stopping distances of expelled particles provide another telling illustration of the complexities involved in droplet transmission: particles smaller than 488 μm (cough) or 232 μm (sneeze) will not travel further than 60 cm. (Quantifying the routes of transmission for pandemic influenza. Bulletin of Mathematical Biology. 2008; 70:820–867). Although these data are related to influenza viruses, the physical properties of a droplets are the same. They punch a hole in the established in 1930th 6 feet (2 meters) distance notion (Wells WF. On air-borne infection. Study II. Droplets and droplet nuclei. American Journal of Hygiene. 1934; 20:611–618). A researcher in MIT from Fluid Dynamics of Disease Transmission Laboratory, however, found the distance should be 27 feet (810 cm)  or even more due to turbulent gas cloud dynamics during sneezing by infected person (Turbulent Gas Clouds and Respiratory Pathogen Emissions. Potential Implications for Reducing Transmission of COVI-19. JAMA online, March, 26, 2020). 

In a close expiratory event, a close cough is unlikely (≈1% probability) to generate traditional droplet transmission (i.e., direct deposition on the mucous membranes), although a close, unprotected and horizontally-directed sneeze is potent enough to cause droplet transmission (Quantifying the routes of transmission for pandemic influenza. Bulletin of Mathematical Biology. 2008; 70:820–867).

 Virus inactivation should be taken into account, as well as gravitational settling of particles with supposedly viruses. This understanding can contribute to rational use of the mask under certain working conditions and in private life.

Aerosol transmission is far more dominant than contact transmission for influenza. Aerosol in long-range transmission should be divided into indoors and outdoors transmission. The latter is in the background of the personal mask (“street mask” indoors and outdoors) employment. Airborne transmission through droplet nuclei does not require face-to-face contact with a person who is prone to be infected.

SARS-CoV-2 virus in COVID-19 is completely similar to influenza viruses by the physical features of distribution in droplets transmission. The differences might start at the level when the virus is uncoated from its envelop and start relationship with the invaded host.


Indoors transmission occurs as droplet spray of predominantly large droplets up to millimeters settling directly or by indirect contact on mucous membranes or by inhalation of either large respiratory droplets (>10 μm in diameter) or small airborne droplet nuclei (<5 μm in diameter). Transmission requires the direct deposition of large droplets on the mucosa of a susceptible person. The only mechanisms that occur immediately after expulsion (<1 s) are in a restricted space.

Outdoors, transmission occurs at close ranges rather than over long distances. The airborne transmission in this situation is unlikely to be of significance in most clinical settings. (Transmission of influenza A in human beings. Lancet Infect. Dis. 2007. 7:257–65). Outdoor aerosol transmission is not likely due to dilution and dispersion by ambient wind speeds and turbulence, whereas in closed environments, particularly with low ventilation, aerosol transmission is more likely. (High infectivity and pathogenicity of influenza A virus via aerosol and droplet transmission. Epidemics. Volume 2, Issue 4, December 2010, Pages 215-222).

Airborne transmission is only important indoors. Outdoors, where virus discharge is by dilution, air circulation and higher virus inactivation, the transmission is, in my view, questionable.

The low humidity and lower temperature environment would promote the viability of SARS-CoV-2 in the droplets and impaired ciliary clearance and innate immune defense, for robust access to the deep lung tissue and rapid transmission between infected individuals.

Stability of Respiratory Viruses

The stability of SARS-CoV-2 was similar to that of SARS-CoV-1 under the experimental circumstances tested. This indicates that differences in the epidemiologic characteristics of these viruses probably arise from other factors, including high viral loads in the upper respiratory tract and the potential for persons infected with SARS-CoV-2 to shed and transmit the virus while asymptomatic. There are some statements that the virus can remain viable and infectious in aerosols for hours and on surfaces up to days (depending on the inoculum shed). These findings echo those with SARS-CoV-1, in which these forms of transmission were associated with nosocomial spread and super-spreading events, and they provide information for pandemic mitigation efforts. (Aerosol Surface Stability New England Journal Medicine on April 12, 2020).

Some sources state that the virus can hang around in the air for at least 3 hours, but this statement does not have a reliable experimental support. A special study reports the virus viability 5.6 hours on stainless steel and 6.8 hours on plastic surface. These sporadic data are only partially related to the topic of this post, namely casual mask wearing. They are the decontamination and disinfection issues, which require a separate discussion.


The presented above available to me research data are in the background of my understanding of wearing a protective mask just in private life outside a medical facility, diagnostic or clinical. I am open to changes in my view if new data would look reliable to me.

A special masks comparison discussion will be posted later. Now, I want to discuss the rationality of manufactured or various self-made “masks”, simple improvised scarfs.  

Should the use of face masks be recommended during a pandemic on the basis of current knowledge of airborne or droplet transmission?

It looks like airborne transmission is important only indoors.  Outdoors, where virus discharge is by dilution, air circulation and higher virus inactivation, the transmission is, in my view, questionable. However, even indoors use of a face mask requires some sober considerations.

Infection part

If we exclude very exceptionally rare situation when a COVID-19 ill person coughs or sneezes in close proximity (2 feet), the casual face mask is used to protect from viruses that presumably exist in the room. They are distributed diffusely in the area of a person presence. It means, that the same particles of droplets, containing viruses, are at the surface of the mask and other areas of the face (forehead, eyes, remaining part of the cheeks, etc.), as well as hear, hands and cloth equally.

Viruses invade predominately the respiratory tract via the nose or open mouth and less through eye conjunctive. The droplets containing viruses don’t know where the nose is, they don’t have a GPS. The wet and warm mask provides the virus in droplets (droplet nuclei) a comfortable dwelling surface. The mask becomes a hotbed for viruses. When the mask is taken off, the droplets inevitably are disseminated in close proximity to the “infection gates” (nose, mouth, eye conjunctive). The person’s wet and warm breath through the mask also provides the surrounding face’s skin with some additional humidity for viable viruses which would otherwise dry out on the skin’s surface. Semidried droplets become lighter for take off from the skin. By air circulation, hands manipulations and other ways, they can find their way to the nose or mouth because the power of active inhale prevails over power of the passive exhale.

Practical advice: when the face mask is taken off, wash with soap not only your hands but also your face and the exposed parts of the neck.

Breathing through the mask is not the best evolutionary achievement for the humans. The nose is the first line of defense. The nasopharyngeal and oropharyngeal areas are the second lines of immunological defense. Would it not be reasonable to let them do their defense work under natural physiological conditions if some amount of viruses sneaked behind the infection gates? We cannot seal them off from entry of a pathological agent completely.

Epidemiological concern   

Very rarely, the masks are taken off according to the infection disease professional rules – slowly rolling with the mask’s outside in. Actually, facial masks designed in the respirators dome form cannot be taken off in this manner. Such way of taking the mask off is also just impossible for an improvised mask made from a kerchief. There are other details of handling the face masks outside the medical facility that makes it, in my view, useless for an individual’s employment and undesirable from epidemiological point.

Community life aspect

We see that almost all people in China are wearing masks. Besides, they are used to wearing them due to living in highly polluted cities, so this is more of a psychological phenomena.

Of course, some exceptions should be made for immunocompromised individuals, but they should be instructed to follow safe use of the mask which should protect them not only from SARS-CoV-2.

Some additional questions

Is a grocery store, supermarket or smaller size store an indoor space during COVID-19?

Do we want a socially devastating life when people move around with Pitbull’s muzzles? How long will this last, and who will decide when it is time to take the masks off? Would it be for now right to go on a date equipped also with gloves, perhaps double gloves just in case, and a respirator? Maybe, a mask will be a part of our attire for a foreseeable future, keeping in mind second waves of many epidemics?

While working on the cytotoxins antibodies history in experimental immunology, I was impressed by how deep immunologists dived into the cell structure. During the current post preparation, I was surprised by how shallow the swims into the infectious epidemiology are in determination of dissemination of airborne infections and immunological responses in population.

Would it not be right, for the institutions in charge of just this current epidemic to arrange simultaneous multiple corroborative and clandestine from each other studies of the infamous 6 feet social distancing? Is not a shame that this distance is based on 90 and 70 years ago studies (WF Wells)? It would not be a long and expensive study.

Is not it time to separate the real knowledge from urban legends in such a serious act of placing the whole country on a complete standstill?

Is the probability theory still a tool for mathematical models based on reliable data?

Meanwhile, let people have some fun in masks creation, like below. Bandanas (Bandannas) now became a fixture of fashion.

However, to make the mask as a part of attire in public areas is , in my view, an unsubstantiated overkill. The society would pay a substantial price for such self-destruction.  

N95 and other Masks


This post is a comparative review of different types of protective masks which are used or suggested for use during the COVID-19 epidemic. These materials are continuation of the previous post COVID-19 and the Mask where some “theoretical” data the about SARS-CoV-2 virus and conditions of the virus distribution are discussed. N95 respirator is the most popular protective mask. It will be discussed in some detail.

Surgical mask

Surgical mask, the mother of all protective masks, was tested more than 100 years. However, it was designed to protect the s space of manipulation from the care provider’s infectious contamination, as well as the ambient environment, namely the room.

 Surgical mask, the older variant

Current variant of a surgical mask

Optimal professional mask in a health care facility with suspected SARS-CoV-2 virus

Below is the optimal professional protective mask with or without a respirator for an anesthesiologist, respiratory therapist, or other person in charge for work with a patient on the ventilator for a short time of the actual procedure management.


The N95 respirator on the figure B looks superfluous, but perhaps, for operational purpose when the anesthesiologist spends the most time in procedures which do not assume the direct contact with the patient discharging infectious material.

N95 respirator

3M respirator

Different types of N95 respirators/masks

Respirators are used predominately in construction, sometimes agriculture, and in healthcare for protection against airborne infections, including viruses and now in COVID-19 epidemic.

Respirators are tested in the direction of inspiration (from outside to inside). The tests take into account the efficiency of the filter and leakage to the face. N95 respirator (in Europe disposable particulate respirator FFP2) have a minimum of 94% filtration percentage and maximum 8% leakage to the inside. As a standard, insulating respirators are most used (the filtering consists of a facepiece and a filtering device, sometimes with an exhalation valve).

According to CDC “The ‘N95’ designation means that when subjected to careful testing, the respirator blocks at least 95 percent of very small (0.3 micron) test particles.” Each SARS-CoV-2 virion is approximately 50–200 nanometers in diameter. 50-200 nanometer is 0.05- 0.2 microns. It means that N95 cannot prevent SARS-CoV-2 virus transmission.  However, the virus is not “naked”. It travels in mucus droplets and droplet nuclei, which are the dried-out residual of droplets presumably containing SARS-CoV-2 viruses. Mucus is of 95% water.

Again, an effective N95 respirator is designed to achieve a very close facial fit (8% leakage). Never mind that it is not achievable in hairy face.

Now, I want to address a significant, in my view, detail in using N95 respirator for individual’s protection from viruses in the air space which is in the person’s proximity. Otherwise, why bother to use a respirator.

The respirator catches droplets (>5 micro) and containing viruses droplet nuclei (≤5 micron) at the protected area in the same amount as at all other areas of the face, including adjacent to the respirator’s edges. While at the nose area the respirator is sealed by a metallic insert, the rest has certain narrow (8% leakage space between the face and the edges).

The droplet nuclei are water substances moving in the air, like fog, which is condensed water droplets. For understanding what is occurring in the narrow area (8% leakage) between the respirator’s edges the face, we need to apply some physics, particularly the Bernoulli principle.

When a fluid flows into a narrower channel, its speed increases (Bernoulli principle). With a higher pressure on the outside, the high-velocity fluid forces other fluids into the stream. This process is called entrainment. An aspirator uses a high-speed stream of water to create a region of lower pressure. A paint or perfume sprayers, a carburetor or a chimney are examples.

The kinetic energy of the droplets flow is generated by the gradient between air pressure outside the respirator and the negative pressure of the person’s inhalation. Dust or other firm particle would stop by friction.  Their form is certain. The droplet nuclei is water. It can change its form. It sneaks inside the respirator without opportunity to go out because the exhale is passive. The number of sneaked droplet nuclei is minimal, but a person is breathing around 15-18 times per hour. The wet and warm mask provides the virus in droplets comfortable dwelling. The mask becomes a hotbed for viruses. The droplet nuclei viruses content can go without any difficulty in the” infection gates” as nose and mouth.  

In a case of a mask similar to regular surgical mask, there is an air flow around the mask’s edges without forcible entrainment. Designed for preventing firm particles inhalation, the N95 respirator without 100% face fit, which is practically impossible, is, in my view, unacceptable for biological object like SARS-CoV-2 virus. I would appreciate any substantial objections to these considerations.

Additional problem of a regular N95 respirator is dome like relatively firm design.  By a person’s exhale, the respirator accumulates on its wet and warm outside surface droplet nuclei with viruses, if they supposedly exist. They can dwell there comfortably until the respirator is taken off. However, the protective device should be taken off by slow careful rolling keeping the external surface inside the roll. This is difficult by the respirators form and fabric. Those are not unimportant details. The infectious material in semi-dried droplets appears in relatively large quantities directly in the areas most vulnerable for the entry during the taken off the respirator.

Other protective masks

As a practical solution, in my view, would be either complete sealing as Figures A and B or the Kimberly- Clark FLUIDSHIELD mask type with (better) or without shield.

Kimberly- Clark FLUIDSHIELD mask has five layers. Both the internal and external (orange stripes) layers are water permeable. The three layers between them have different degrees of water resistance. Although the company advertises them as LONCET breathable film, these layers, in my experience, make the mask uncomfortable for prolonged use because the area between the mask and the face is overheated and over-saturated with exhaled carbon dioxide that decreases the percentage of oxygen in the inhaled air.

Kimberly- Clark FLUIDSHIELD mask. 

Protective Face Shield Visor, like offered by Htovila or Decdeal, is seemingly convenient. It definitely protects from dust and splashes and other situations of direct infectious material application. But it does not substitute the mask which it is necessary as protection from airborne infectious material, like coronaviruses. PET (polyester) material is relatively rigid and difficult to adjust to the protective gown for the neck protection. In my opinion, and experience of working with different masks, the Kimberly- Clark FLUIDSHIELD mask upside down (see above) wearing is preferable.

Decdeal Safety Face Shield

3M™ Full Facepiece Respirator 7800 Series looks solid, though intimidating, but it does not solve the main problem of the standard N95 respirator, namely face-fit adjustment that in the case of protection from viruses in crucial. Some suggestion to use this devise with reusable filter is controversial. In my view, it is unadvisable under condition of COVID-19 epidemic.

3M™ Full Facepiece Respirator 7800 Series

The development of protective mask will continue. Hopefully, the inventors would not think that the SARS-CoV-2 virus is going to reach specifically a cupper insert to be destroyed.

Meanwhile, if people feel comfortable by using a mask, let them do it, including bringing some creativity and fun, like the mask with owls on it. Positive spirit is part of healing from real dangers and unsubstantiated fears.

However, bandanas (bandannas) and similar creative protection “devices” are not innocent from infectious epidemiology point. We are not at the masquerade. This issues will be discussed in a special post later.

The main thing is that manufacturers understand design principles of a protective mask against the airborne infection. And the mask is correctly used. Both posts are written on the background of my experience in anatomic pathology as a pathologist, pathologists’ assistant, morgue attended, and grossing technologist.

Protective Face Covering Folly

From Chicago area food market store email (italics and bold added):

Shop and Save Market Wed 4/22/2020 3:00 PM Face Mask Required Effective April 22nd,                                               Dear Customers, We respectfully request that you wear a protective face covering when shopping with us. For your and our safety & protection. Mask, Homemade Mask, Bandana or Scarf.

For your safety & protection

If a person is surrounded by SARS-CoV-2 virus in a given place, otherwise a protective face covering for you is not needed, viruses are disseminated equally around the head and neck areas at least. Even when virus’s carrier sneezes in close proximity at the person wearing a bandana.

The droplet nuclei (containing the viable viruses, in sneezing 40 million, in coughing only 5 million) do not have any knowledge where the “infection gates” (nose, mouth, eye conjunctive) are. Droplet nuclei land indiscriminately on every place. However, a mask, bandana or scarf provide them conditions in maintaining their comfortable dwelling by warm and wet person’s breath. Although the forehead or the neck might be sweaty, at these places and especially on the cloth viruses are less viable by losing their water surrounding.

The protective mask becomes a hub for viable viruses. The face cover should be treated as biohazard material. Are these masks taken off according to infectious epidemiology rules avoiding contamination of hands, face, and cloth? Are they disposable? More than likely not. How are they discarded? And numerous additional epidemiology questions.

For our safety & protection

Apparently, this is about preventing SARS-CoV-2 virus contamination the indoor space. Face covering to protect others from the potential carrier of viruses could be rational if a symptomatic people come in droves to the enclosed public spaces and sneeze and cough out their infectious material. This is very much questionable now. Asymptomatic viruses’ carriers distribute them without sneezing and coughing. Workers, who perform in-person jobs, now have separating from public plastic screens and use non-medical grade face coverings.


Nasopharyngeal area is one of the first lines of defense in the fight with a virus, which includes the initial cellular immunologic response. This defensive zone is the product and gift of humans evolution. The face covering does not contribute to its effective function. I know this as a person who worked many hours using a protective personal equipment mask.

In contrast to (PPE), which is a necessity under certain conditions for medical and other professionals, in my definite believe, the face covering in public space indoors and definitely outdoors is not only unnecessary but wrong under COVID-19 epidemic.   

Compulsory Protective Masks

On April 24th, Michigan Governor Gretchen Whitmer signed EXECUTIVE ORDER No. 2020-59 Temporary requirement to suspend activities that are not necessary to sustain or protect life. The current post discussed only the point 15, which is related to mandatory protective face covering.

15. Effective on April 26, 2020 at 11:59 pm:

(a) Any individual able to medically tolerate a face covering must wear a covering over his or her nose and mouth—such as a homemade mask, scarf, bandana, or handkerchief—when in any enclosed public space.

(b) All businesses and operations whose workers perform in-person work must, at a minimum, provide non-medical grade face coverings to their workers. (bold added)

The purpose of this order is in protecting people of Michigan from you, the suspect of SARS-CoV-2 virus carrier. You, perhaps intentionally through sneezing or coughing, or even unintentionally being asymptomatic would contaminate any enclosed public space, especially “workers perform in-person work.” Never mind that according to point (b) All businesses and operations whose workers perform in-person work must, at a minimum, provide non-medical grade face coverings to their workers (italics and bold added). Scared by the death toll in Detroit, people are of each other more than 6 feet because they don’t carry a yardstick to measure the safe distance.

The Governor’s order obliges me to wear a mask which is, in my believe, a danger to me and others under current conditions. I can defend the notion that wearing masks in public life, including enclosed public space, is founded on unsubstantiated premises (see three previous post on this subject).

COVID-19 epidemic generated a commonly accepted by public notion regarding wearing a protection mask. It is based on a natural instinct to cover the “infection gates”, understandable to everyone, relatively cheap, easily achievable, psychologically acceptable. Even Surgeon General Dr. Jerome Adams could show how to do a mask at home. Although when he took from his pocket a mask at the White House briefing, he demonstrated his innocence in following epidemiology rules.

Here is an excerpt from on of the most reputed journal in internal medicine (bold added). New England Journal of Medicine  on  May 21, 2020 Perspective Universal Masking in Hospitals in the Covid-19 Era

Michael Klompas, M.D., M.P.H., Charles A. Morris, M.D., M.P.H., Julia Sinclair, M.B.A., Madelyn Pearson, D.N.P., R.N., and Erica S. Shenoy, M.D., Ph.D.

“We know that wearing a mask outside health care facilities offers little, if any, protection from infection. Public health authorities define a significant exposure to Covid-19 as face-to-face contact within 6 feet with a patient with symptomatic Covid-19 that is sustained for at least a few minutes (and some say more than 10 minutes or even 30 minutes). The chance of catching Covid-19 from a passing interaction in a public space is therefore minimal. In many cases, the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.”

However, when the hyperactive authorities impose as mandatory scientifically unproved and epidemiologically wrong action on the general public, it is not good. This order looks as a politically motivated action to impose more and more control upon society.

The next will be obligatory testing (this issue I’m going to explore in a serial next posts). The rationality of seatbelts or helmets were proved. Mandatory masks in enclosed public space open the window for other restrictions in public life with questionable premises. They will gradually crawl in. Do we want to live in China or even in splendid, almost sterile Singapore?  Yes, almost everyone is wearing a mask outdoors in Japan, but a mask is not out of their culture conscience.  

Independently where the Wuhan virus came from, now poor, hated by everyone SARS-CoV-2 virus is a part of the environment with the same rights as mosquitos, elephants, and humans. A crazy question about protective masks use. Would not be right for humans to join Saints Indians who cover their mouth with a cloth (Muhapatti) that prevents them from swallow by accident a mosquito?

Silly humor in gray times, when for political gains, a Russian roulette is played in the uncertainty casino. Political weaponization of a medical crisis is suicidal for democracy and for the society eventually.

This post is the last of four previous on the masks subject.  The goal was bringing some rationality in their use by distinguish masks as a part of protective equipment for professional and just protective face covering. The main focus was to make a dent in protective face covering understanding which is at the level of delusion, unhealthy for an individual and the society.

Personal Protective Equipment (PPE) and Beyond

Watching the health workers in China, I always doubt that they could work in their protective attire efficiently for a long time. They looked more like an intimidating alien from a space ship. What are their boots for? As I can see on the TV, people, who are working in the patients wards in USA,  are ”packed” in Personal Protective Equipment (PPE), which does not contribute to efficient work. The medical personnel is afraid of a patient, the patient is intimidated by the caregiver’s attire appropriate in a virology laboratory, BSL-4 . This is not a healing atmosphere in a hospital’s ward. The mutual fear might have contributed to the lethal outcomes.

Is SARS-CoV-2 different from other previously known Corona viruses? As far as we know from the open press, this virus is not different except more transmittable and contagious, which is still questionable, and unfortunately more excessive morbidity and obviously mortality, like in Italy. The Italy’s case still is waiting for a sober analysis.

These introductory words preclude my reflections on personal protective attire donning/don off under more benign conditions, namely in anatomic pathology laboratory, but similar by the necessity of understanding the principles and attention to details.

As far as Personal Protective Equipment (PPE) is concerned, Occupational Safety and Health Administration (OSHA) in Guidance on Preparing Workplace for COVID-19 states: ”Workers, including those who work within 6 feet of patients known to be, or suspected of being, infected with SARS-CoV-2 and those performing aerosol-generating procedures, need to use respirators.”

The most popular is NIOSH-approved fit-tested N95. On the paper this looks easy. OSHA recommends the employer, the employer requires the employee, but it is extremely difficult to work by using a N95 respirator for a prolonged time.

No any anatomic pathology laboratory work meets the mentioned above requirement as well as “close contact” situation. The weak place is the frozen section procedure which requires a separate presentation.

Center of Disease Control and Prevention (CDC) defines “close contact” as being about six (6) feet (approximately two (2) meters) from an infected person or within the room or care area of an infected patient for a prolonged period while not wearing recommended PPE. Close contact also includes instances where there is direct contact with infectious secretions while not wearing recommended PPE. Close contact generally does not include brief interactions, such as walking past a person.

CDC does NOT currently recommend the general public use face masks. Now (3/3/2020), the CDC changed their approach. The use of mask in general population will be addressed in one of the post the next week.

When I see medical personnel in an Italian patient’s ward, my feeling is that they cannot provide an effective care in such attire despite ventilators and best in the world medication. They require special personnel to dress and undress them. They are living people who have physiological needs. In my understanding, such PPE can be used for a short time during procedures which include placing or removing from a ventilator, suctioning air ways, bronchial lavage, etc.

In the complete adherence to OSHA for COVID-19 recommendations, a workable attire should include following items:

a disposable plastic gown (tied on the back),

cap (covering ears completely),

goggles type glasses,

a protection mask with a shield,

and disposable gloves.

In my view, double glows are obligatory (explanation later). Is the shoes cover advisable? During an epidemic yes, just to prevent spreading infection outside the laboratory. This is not a cavalierly rather a realistic approach.

In the gear

For many years, I used the Upsidedown Kimberly-Clark FLUIDSHIELD mask on a regular basis during my work in the surgical pathology grossing room. (See more details The Protection Masks post).

The main crucial point of using PPE is how the attire is donoff. In this regard, the ways for infection transmission would be appropriate to present. This knowledge would be useful for the general public as well.  

The SARS-CoV-2 virus, which is the source of concern, dwells in wet surroundings of more or less size invisible droplets. It comes from their human carriers (ill or not). The virus does not jump, but the semi-dried out virus, which is attached to the protective attire (otherwise why the attire is used), can reach the “entrance gates” (medical term) for infection (nose, mouth, eyes) just at the moment when the attire is taken off. This brings us to the rational mode how to take off PPE.

On the TV, I’ve seen how a doctor took off his protective gown and gloves (first) with fast movements while placing them into an open large bucket. This is dangerous for him and the environment, especially in the limited room space under air conditioning circulation. Multiple videos present donning and doffing PPE with or without multiple hands sanitation, but each of them demonstrate that correct actions are not ingrained in their mind. A person did everything in general correctly, but in the end he took of the cap completely wrong.

There are certain common-sense rules which I have inherited during my training and work as an epidemiologist.

First, the attire should taken off be in a slow motion manner.

Second. Following a certain sequence of items, which are taken off :

with still gloves on, the gown is taken off the first; it is slowly folded with external side inside and rolled before place in the collection bucket;

then the double glow is taken off slowly,rolled exposing their internal side, placed in a trash bucket;

then the cap is taken off in the same manner;

then protection of eyes/face goggles/glasses/mask with internal gloves still on.

The internal gloves are taken off slowly, rolling the glove from one hand and taken off from the second hand using the rolled glove as a tool. Both rolled gloves are slowly placed in the trash bucket.

Hand wash and all open face’s hair areas (eyebrows, mustache, beard) by closed eyes.

The process of donoff the protective attire is very important in preventing self-inoculation. The most significant is the contamination of the laboratory environment. This issue will be addressed in following post/s.

The presented PPE principles are applicable in private life. Understanding of the rationale of infection protection can be helpful in different everyday life situations. The angel is in understanding of the details.

As an illustration of the detail’s angel, a comparison of two PPE types wearing by two anesthesiologists working in hospitals apart the entire country, at East and West shores. Both are using a protective attire which covers the head, face, and neck, the figure below.

The head, face, and neck mask.

On the figure A, the mask is above the gown, while on figure B it is beneath the gown.


On the figure B, the protection is complete. On the figure A, an additional respirator was required.

N95 respirator

Although the mask on figure B is less comfortable and manageable, the short time of the anesthesiologist’s encounter with potentially material makes figure B use of the mask preferable.

However, the most significant detail is violation of the basic rule of the take off the PPE on the figure A. The gown, the larges area, which might be contaminated by infectious material, should be taken off first, the face and the neck should be open the last. Unless the infected patient sneezes, coughs directly in close (60 cm) proximity of the infection recipient, the infection in the operating room is in an aerosol form, which is diffusely spread by contaminating the largest part of PPE, the gown. In figure A, it is difficult to take off the gown first by yourself safely. The gown should be taken off following certain rules to prevent self-inoculation and contamination of the room.

The safety angel is in details.

The Kimberly-Clark FLUIDSHIELD mask under COVID-19 condition

While observing the protection mask in laboratories, I’ve noticed that some are “overdressed” making work uncomfortable by leaving areas of potential exposure unprotected. Below is the excerpt from my Grossing Technology book’s Occupational Safety section Protective Mask. This observation is especially significant during COVID-19 epidemic.

In the case of potential exposure to tuberculosis, AIDS, SARS – coronavirus, Methicillin-resistant Staphylococcus aureus, etc., a different kind of protective mask should be used. The Kimberly-Clark FLUIDSHIELD mask is definitely advisable,


by wearing it in the upsidedown mode (Figures 15-6 and 15-7).

The mask’s shield touches the gown .

Obligatory protective glasses.

First, two internal layers are made from unwettable material. Designed to prevent penetration of splashes, the mask is not suitable for a prolonged use. The breathing area is overheated because the mask hampers evaporation. There is also over saturation with exhaled carbon dioxide that decreases the percentage of oxygen in the inhaled air. If we add undesirable reflections of the plastic shield (WrapAround SPLASHGUARD Visor), the conditions of using the mask become more unfavorable. It is more reasonable to wear the Kimberly-Clark mask with the plastic shield upside-down. In this situation, the area of air circulation is larger.

Second, while using the “modified” Kimberly-Clark mask with the shield down, I noticed that many droplets of blood, stain, and other fluid could be found on the plastic shield. It means that the chin and the neck, as more vulnerable to contamination than the forehead, are more protected from splashes and spatters. The shield reaches the ubiquitous blue protective gown like Convertors (ALLEGIANCE’s Impervious Gown w/Thumbhooks, Universal). One lower fold of the mask can be loosened to make the mask longer or the plastic shield can be cut to make it shorter if it is necessary for the individual adjustment. The lower strings can be tightened or loosened depending on the type of the processed specimen.  The use of protective glasses with solid side shields at the grossing table is a necessity and the OSHA’s requirement without any exception.

If an air permeable light fabric extension to both sides of the mask were added with strings tight behind the neck, this design would make the mask more protective and comfortable for a prolonged work.(Figure 15-8). This “improvement” would not substantially increase the cost of the mask.The Kimberly-Clark FLUIDSHIELD mask line production had already been established for many years.

Figure 15-8.

Perhaps, some other vendors will come across this post and implement this principle of a protective mask design.

Such type of a protective mask would be useful now and after the tide of deaths and fears. Only a simple design is workable.