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“There is no scientifically proven evidence that the wearing of masks is ineffective. On the contrary (…), the latest biological discoveries concerning the penetration of the SARS-CoV-2 virus into human tissues (…) suggest that the main mechanism of virus transmission is not small aerosols but large droplets, and therefore the wearing of surgical masks guarantees a higher level of protection by everyone » – say the drug. Dariusz Tuleja and biologist Dr. Damian Ryszawy.
WHO: Wearing masks by everyone can do more harm
According to WHO recommendations, protective masks should wear:
- persons sick with COVID-19;
- people with suspected SARS-CoV-2 infection or having symptoms such as coughing or sneezing;
- people caring for people suffering from COVID-19 or people suspected of being infected with the coronavirus.
The World Health Organization has emphasized many times that wearing masks is not always good for our health. The WHO is concerned that people who wear masks feel safe and thus neglect other forms of protection against the coronavirus, such as hand hygiene and social distancing.
“There is no scientific evidence that there is any benefit to the mass wearing of masks by the population on a massive scale. On the contrary, there is evidence that the misuse of masks causes harm ».
For many people, however, these recommendations and recommendations turn out to be insufficient. Why?
It is known that many people pass the coronavirus infection asymptomatically, which means they should be treated as sick and wear face masks, but they don’t because they don’t know about their disease.
Face masks. Everyone wears it, so do I.
Dariusz Tuleja, an ophthalmologist from the Specialist Health Care Center in Koło and Dr. Damian Ryszawy – a biologist from the Department of Cell Biology, Faculty of Biochemistry, Biophysics and Biotechnology of the Jagiellonian University in Krakow, decided to explain the subject on the basis of the scientific data contained in the report «COVID-19: WHY WE SHOULD ALL WEAR MASKS – THERE IS NEW SCIENTIFIC RATIONALE », developed by Professor Sui Huang of the Institute of Systems Biology. What conclusions did they reach?
“The official recommendation in the United States (and other Western countries) that the public should not wear protective masks was motivated by the need to provide an adequate number of masks for healthcare professionals,” argued the authors of the report, explaining that the guidelines had no scientific basis. Public orders to wear masks in Asian countries have contributed, in their opinion, to the “flattening of the incidence curve”, which is said to be the best proof of the effectiveness of widespread covering of the face.
Therefore, in the report “COVID-19: Why We Should All Wear Masks – Scientific Justification” we read that while the policy of universal wearing of masks certainly does not completely eliminate the risk of coronavirus infection, it may reduce it. Why not eliminate? If only because not everyone has the same quality mask, not everyone is able to put it on and use it properly.
«Obviously, N95 surgical masks and masks, if improperly worn, do not provide complete protection. But if the goal is to “flatten” the curve, we must abandon binary black and white thinking and look at the problem in different shades of gray. We can no longer claim that masks are “not effective”. We cannot allow the ideal to be the enemy of good. What if the partial protection provided by leaky surgical masks, and even self-made ones, reduces the likelihood of transmission to an extent similar to the recommended (equally imperfect) separation of more than 2 meters or not touching the face? » – we read in the study.
Ballistics of cough droplets and other arguments
«Taking into account the ballistics of cough droplets and the latest research on the biology of SARS-CoV-2 virus transmission (which causes COVID-19 disease), it can be concluded that any physical barrier, even provided by shapeshifting masks, can significantly reduce the efficiency of the spread of the virus »- write the authors of the study, explaining that the mask ineffectiveness theorem is incorrect in three respects: in logic, in the mechanics of transmission and in virus biology.
How logic speaks for the common wearing of masks?
As we read in the report:
«Of course, no mask, be it the NIOSH-approved tight-fitting N95 mask, a loose-fitting surgical mask or a home-made mask, provides excellent (100%) protection. But imperfect protection does not mean the mask is “completely useless”, and neither does an unfilled glass need to be empty: I will gladly take a 60% full glass of water when I am thirsty. The lack of (protection) evidence is not evidence that the mask does not protect. But in our binary black and white world, the official message that surgical masks are “ineffective” may have sent the wrong message: that they are absolutely useless. Unfortunately, due to the black and white picture painted by officials, the discussion about the effectiveness of masks has been stifled, and with it the possibility of encouraging industry to increase production of these very cheap protective measures. »
DRAWING: Droplets larger than aerosol droplets (> 10 μm) evaporate or fall to the ground at a distance of less than 1 m from the source when exhaling (at a speed <1,5 m / s). In contrast, larger droplets (> 0,1 mm) when ejected at high speed by coughing or sneezing, may be carried by the air stream further 2 m or even 6 m, respectively.
The authors also use arguments in the field of mechanicsby carefully analyzing the pathway that viruses spread from person to person. For this purpose, they divide the drops that sneezers excrete into:
- aerosols, i.e. drops with a diameter of less than 10 micrometers, which can stick to the air, be carried by wind, ventilation, spread freely around the rooms;
- spray droplets, larger than aerosols, with a diameter exceeding 10 micrometers, reaching sizes up to 100 micrometers. These droplets have been found in studies to hit a surface 1,5 meters away when breathing. However, as we read:
Coughing or sneezing can shoot them like projectiles from the mouth with a «muzzle velocity» of 50 meters / second (for sneezing) or 10 m / s (for coughing), and the drops can reach up to 6 meters away. If so, the aforementioned “safe distance” of 2 meters in social gatherings may not be enough
In other words, larger drops can easily go to our nose, throat, trachea, bronchi and lungs, and aerosols – even to the alveoli. Professional surgical masks protect us against droplets from getting into the alveoli. According to the authors, any physical barrier protects against the absorption of the drops.
DRAWING: The major route of viral entry is probably due to the large aerosol droplets that deposit in the nasal cavity, where cellular ACE2 receptor expression is highest. It is a transmission path that can be effectively blocked with simple masks that constitute a physical barrier.
Tuleja and Ryszawy refer to an interesting study carried out in 2008 in the Netherlands, which compared three types of masks in terms of filtering ability:
- a homemade handkerchief mask,
- standard surgical mask,
- FFP2 – European equivalent of N95 masks.
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The authors of the study found that FFP2 masks filter out 99% of aerosol particles, and surgical masks four times, and homemade masks – three times reduced the content of aerosol droplets. It is also known that in the case of larger drops contained in the cough, this difference would be even smaller.
DRAWING: Filtering effect of small droplets (aerosols) for various masks: homemade handkerchief, surgical mask (3M “Tie-on”) and FFP2 mask (N95). Numbers are scaled to a reference of 100 (droplet source) for illustrative purposes, calculated from the PF (protection factor) values in Table 2 by van der Sande et al., 2007. Measurements were made with a Portacount which records airborne particles ranging in size from 0,02 to 1 micrometer at the end of a 3-hour period of wear without physical activity. The number covered is the median of 7 (or 8) adult volunteers per group. Protection at the start of the test was similar for a tissue and surgical mask, but for FFP2 the protection was double. Children had much less protection (see van der Sande et al. 2007)
What about the transmission of drops from a coughing person? “Even an imperfect mask can provide protection that is at least comparable to the effects of the recommended 2 meter interval in social contact, washing hands and avoiding touching the face,” the study authors explain.
The third group of arguments in favor of the widespread wearing of masks in the epic coronavirus are arguments from the field of biology.
As Tuleja and Ryszawy write in their study:
«SARS-CoV-2 virus, like any virus, must attach to human cells using a specific receptor binding method (simplified: the lock-lock principle, in which the virus has a key and the cell has a lock on its surface that is complementary to key). In order to start replication, the virus must penetrate inside the cell and use its molecular mechanisms to replicate its own particles. In the case of the SARS-CoV-2 virus, the viral surface protein “Spike protein S” is the “key” and must closely match the “lock” where it is expressed (molecularly presented) on the surface of the host cells. The cell blocking protein used by SARS-CoV-2 is the ACE2 protein. »
Notably, ACE2 levels are very low in the lungs and alveoli, and much higher in the cells that line the nasal cavity. It follows from this that «the transmission of SARS-CoV2 virus occurs largely by large droplets of coughing or sneezing, which constitute a large part of the spray (in coughing / sneezing) and settle in the nasopharynx due to their size – exactly where ACE2 protein molecules are present, allowing the virus to attach and enter the host cells ». The path of this transmission can be successfully interrupted by a simple physical barrier, i.e. a mask.
To sum up, each mask, including the one made by yourself, is a better protection against infecting yourself and others with the virus than without it.
As they explain:
“Therefore, surgical masks, perhaps even your home-made ski mask, bandana, or scarf, can provide better protection than the general public advised not to wear masks presented by a government official in the initial period of the epidemic. N95 masks may offer little more protection than you might think. It is worth adding that the CDC suggests the use of a scarf by healthcare professionals when face masks are not available. Practically and socially, surgical or self-made masks, if properly used, will not hurt at worst, and can help at best (remember to throw them away or wash them after use without touching the outer surface). These simpler, inexpensive masks can be enough to flatten the disease curve, perhaps a little, maybe considerably. Importantly: using them will not take precious N95 respirators away from healthcare professionals. »
Find out more:
- Everything you should know about face masks [INFOGRAPHICS]
- Obligation to cover the mouth and nose in Poland. What are the types of face masks?
- Here is the WHO recipe for hand sanitiser
- 10 activities for which you must wear disposable gloves
- Should we all wear masks? WHO position paper