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I am meeting my friend Carlos to go to the mountain to climb; We hadn’t seen each other for a long time and we both wanted to. For a while we were deciding the routes and the material that we should take, when in an innocent way, he asked me:
Do we need to take a mask to the field?
I was not surprised by the question. On March 31, Law 2/2021 came into force, which states that people over 6 years of age are obliged to use masks on public roads, in outdoor spaces and in any closed space for public use, as well as in public spaces. means of transport, that is, in all places and circumstances. That includes the field and the beach, the subway and a boat.
This tightening of the previous rule has generated a great stir and uncertainty. On the one hand, due to the contradiction involved in the imposition of the mandatory use of the mask at all times in open public spaces, allowing exceptions when entering a restaurant or bar. And, on the other, due to the lack of consensus prior to the norm among the autonomous communities, especially those with a large coastal area.
Well of course! –I can say–. Don’t worry, when we meet I’ll explain why.
And that’s how, as the shadow finished falling on the wall we were trying to climb, I found myself giving a whole spiel in the middle of the mountain about why I had answered yes so quickly.
A robot portrait of the “enemy”
Since the beginning of the pandemic, we have put all our efforts into finding out how SARS-CoV-2 is transmitted between us. The scientific evidence accumulated so far indicates that SARS-CoV-2 can be transmitted from person to person by different routes, although they point to air transmission as the main one. What’s more, currently the European Center for Disease Prevention and Control warns of the low ability to spread by contact with contaminated inanimate surfaces.
Spread would occur through inhalation of respiratory droplets and aerosols emitted by a patient. And those droplets and aerosols must reach the upper and lower airways of a susceptible person, depositing on the mucosa of the respiratory tract.
While the size of the droplets (greater than 300 microns in diameter) causes them to fall rapidly to the ground, aerosols, with a diameter ten times smaller than a hair (less than 100 microns in diameter), can remain suspended in the air. during hours. Specifically, they can carry viable virus RNA for at least up to 3 hours, which facilitates the spread of the virus.
The risk of transmission is determined by the increase in production and concentration of contaminated droplets and aerosols, and by the permanence of virus particles in the air in non-ventilated environments.
That is why the risk is multiplied if activities are carried out that increase the generation of aerosols, such as doing physical exercise, talking loudly, yelling or singing. Especially in closed and crowded environments, especially poorly ventilated, which do not allow the aerosols to be diluted. Without forgetting the danger of short distances, where we also contact the droplets.
Masks save us
While we do not have definitive solutions, I am commenting to Carlos – who looks at me incredulously for listening to a summary of the pandemic at the foot of the climbing route – that reducing the risk of contagion requires reducing the concentration of aerosols and reducing the time of exposure to them. Measures such as hand hygiene, social distancing, ventilation of spaces and the use of masks are measures of proven efficacy.
Masks are useful in protecting against the transmission of the virus in two ways. For one thing, they filter the exhaled air, reducing the risk of exposure to others. But they also reduce the speed of the exhaled air, reducing the transport distance of the droplets.
Currently, most of the population have become experts in differentiating the different types of masks (hygienic, surgical, FPP2, FPP3 ..), their protection levels (65%, 95%, 98% ..) and the different UNE standards.
But this knowledge also makes us increasingly critical and skeptical of rules that may contradict what we know. Inconsistencies screech at us, and it shows on the street.
Mandatory consistent with the need
Returning to the initial question, is it necessary to wear masks in the field, the beach or the pool? The Interterritorial Council of the National Health System and the Autonomous Communities, as well as front-line scientists, do not agree on whether the use of the mask is beneficial in all sites – outside as well – regardless of the activity carried out.
Why should one wear a mask on the beach while one sunbathes alone on the towel and yet we can remove it to eat at a restaurant with friends? Some wonder. Others support the imposition of the use of the mask in all circumstances, arguing that the risk of transmission of the virus is the same if I walk along the promenade as if I do it along the seashore.
It seems logical to think that masks do not protect more because they are worn all the time and in all places. Its obligation must be consistent with the need. In this sense, the studies published so far indicate that the mask is necessary (and useful) when the interpersonal safety distance of at least 1.5 meters cannot be ensured.
This excludes sunbathing in a static place and respecting the safety distance. In addition to the fact that, outdoors, the virus has a lower transmission capacity. Although this argument still does not clarify why it is logical to impose its use walking along a promenade and not when walking on the sand.
All these reasonable doubts, added to the dissatisfaction of the autonomous communities in socioeconomic terms, led the Ministry to a “softening” of the norm, just a week later, with a new text prepared within the Interterritorial Council of the National Health System
The flexibility of the rule now includes the permission not to use a mask in periods of rest, with low production of aerosols, in which interpersonal distance can be maintained. The obligation remains if people are on the move. This text has obtained a higher level of agreement among the Autonomous Communities.
The new standard coexists with the criterion of necessity to prevent contagion, which justifies its use in any “natural environment” whenever a safety distance cannot be ensured, with the criterion that justifies its non-use.
The doubts are cleared. It is necessary for all walks, for exercise and any activity except for those incompatible with its use, such as bathing or eating. In short, we cannot take it off to get our feet wet on the shore.
So, is it necessary to wear a mask in open spaces?
Although we must strictly comply with the rules established for a correct social coexistence, we must also be able to see that, when it comes to legislating collectively, generalization can lead to errors.
When exceptions arise – cases in which the application of the general rule seems ridiculous or against good sense – we must be guided by individual logic.
So, friend Carlos, the problem is that sometimes we don’t use logic! To your question about whether we put on or take off the mask, I have answered with another question: is it good to wear the mask in all places and at all times? There is no universal answer. It will be good if it is necessary to carry it, and it will be bad – or even counterproductive – when its use is unnecessary.
For now, we are going to put on the mask well, we are less than five feet away and we are not living together. But above all, take the rope and make sure I do not fall, that I go up to climb.
This article was originally published on The Conversation. Read the original.
The signatories are not salaried, or consultants, nor do they own shares, nor do they receive financing from any company or organization that can obtain benefit from this article, and they have declared that they lack relevant links beyond the academic position mentioned above.