Rocio Magnani
10/10/2020 6:00
Clarín.com
Society
Updated 10/09/2020 16:07
They can be purchased online for
270 pesos
and promise
"greater breathability
.
"
But it is proven that "sports masks", the masks that come with one or two breathing valves, are inefficient for the prevention of COVID-19 infections.
"They are not useful," says the neurologist Conrado Estol.
Furthermore, he explains to
Clarín
: "There is evidence that the masks with the exhalation valves release aerosol with a
high risk of contagion
for the people around those who wear it."
In addition to so-called "homemade" masks, there are different types of sanitary-use masks that come with
exhalation valves
in the center or on the sides.
There are models of the N95, FPP2 and FPP3 that include them, for example.
Masks with breathing valves are not recommended as a method to prevent coronavirus infections.
It could be reviewed how many particles each one filters, but
none of these masks
or chinstraps with a valve
are recommended
as an infection prevention strategy in the framework of the coronavirus pandemic.
Why?
"They are
definitely contraindicated
, because if you are infected, you are risking those around you, the mask with a valve spreads the breath, the air, the drops, the aerosol that one emits loaded with viruses," explains Estol, who gained notoriety in the quarantine for being one of the first to defend the use of the mask, in times when the WHO still advised against its use.
They are
"selfish masks"
, Fernando Simón, the spokesman for issues related to the pandemic of the Spanish Ministry of Health, had described them in June.
It is that whoever uses them is protected when inhaling, but can spread when exhaling.
The United States Center for Disease Control and Prevention (CDC) also advised against its use, an entity that was ahead of the WHO in recommending homemade masks.
In recent research published in the journal
Physics of Fluids
, scientists at Florida Atlantic University triggered a vaporized mixture of glycerin and distilled water through hollow plastic heads to
simulate a cough or sneeze
, and used green laser lights to illuminate the path of that "aerosol".
When testing the N95 masks with valves - which meet the standards set by the US Occupational Safety and Health Administration - they saw
large amounts of particles escape
from them.
In a study at Florida Atlantic University, they tested a mask with a breathing valve.
Such masks are frequently used by construction workers or in workshops to prevent inhalation of dust and other particles, but
they are not allowed in
sterile
medical settings
because they allow the wearer's germs to escape.
As an exception, N95s with valves could be used in medical settings by healthcare workers who are
in contact with infected people
.
In those cases, the objective of the mask is to
avoid contagion from these personnel
.
"Good adaptation and greater breathability", offers a publication of "chinstraps with breathing valves" on the Mercado Libre site.
"Recommended for
running
,
spinning
,
aerobics
,
trekking
and cycling," says another.
They come in different sizes and colors.
Also with the shields of soccer teams.
There are models that reach
4,500 pesos
.
Valved masks are offered for exercise.
During the pandemic, different versions appeared that mimic non-medical exhalation valve masks, especially designed for those who
say they feel "choked"
when walking wearing a mask or for those who want to exercise.
Is that by allowing a greater air outlet, they help reduce the temperature and internal humidity of the mask.
The Florida Atlantic University study found that many of the non-medical masks they tested directly had
faulty valves
, so they didn't even protect
those wearing them
from contagion.
For Estol, "it is true that masks make breathing more difficult, but they do not impede it,
nor do they alter the oxygenation of the blood
or the increase in carbon dioxide."
Along these lines, the doctor explained that tests have been carried out in which the oxygenation of the blood of people running on a treadmill was measured with a saturometer, and it was observed that oxygen levels do not suffer alterations.
“If you are in a square where there are many people running, without it being overcrowded but there is a lot of gene
You have to put on a mask that is tight around the nose, chin and sides of the face, and
loose in front of the mouth and nose
so that there is more room for breathing ”, suggested the neurologist.
But being outdoors without people around, "there is no danger, because you are not exposing another and
you can exercise without a mask,
" he said.
You have to aim for common sense: "It depends on where you are: the gyms are closed, but if you are in a square or a park that is not crowded with people, you don't need to have a mask."
LGP
Look also
Coronavirus: why the universal use of chinstraps could make it milder
They analyzed 14 types of chinstraps: how much each one protects