Several studies are being conducted on the effectiveness of masks: one of them suggests that two masks should be worn to be better protected. A second indicates that the humidity generated by wearing the mask would reduce the severity of the disease.
- Superimposing two masks would make it possible to better adjust the protection to the face
- The humidity resulting from wearing the mask would be a protective element against contamination by the coronavirus
Masks are now integrated into our daily lives. “Wearing a mask is one of the essential measures that aim to stop transmission and save lives“, recalls theWorld Health Organization. But if its necessity is recognized, what type of mask to choose? and how to wear it? The US Centers for Disease Prevention (CDC) issues recommendations on the best way to wear the mask to be well protected, in a publication published on February 13. According to their analyses, it is essential to wear it as tightly as possible when it comes to surgery, or even to wear two when it is a fabric mask.
How to properly wear the surgical mask?
Thanks to tests carried out in the laboratory, American researchers were able to measure the filtration capacity of the masks, according to different criteria. “One of the frequent problems with the masks is that there may be a gap between the mask and the faceexplains the document. When there are these gaps, virus-containing droplets can leak out the sides of the mask“According to these specialists, the surgical mask must be worn close to the face, without there being any gaps. If necessary, they recommend wearing a mask with a small metal rod to adjust it around the nose, or a kind of over-mask, which makes it possible to limit leaks on the sides or to tie knots.No air should pass on the sides of the mask or around your eyes.
The double mask, proven effectiveness
To improve the effectiveness of the mask, the CDC recommends superimposing the layers: a surgical mask covered with a cloth mask. According to their findings, this allows the first mask to be better positioned against the face and creates additional filtration, reducing the risk of leaking droplets. Concretely, an unfitted surgical mask filters 42% of the particles emitted by coughing, a fabric mask blocks 44.3%: when they are worn together, the figure rises to 92.5%. This combination can only be achieved in this way: wearing two surgical masks is unnecessary, and the FFP2 must also be worn alone.
What is the impact of humidity on the level of protection?
Other American scientists, belonging to the National Institute of Health, have taken an interest in the mask. According to their researchthe humidity it creates would be a weapon against Covid-19. When we wear a mask, it generates humidity in the air we breathe, but this hydration of the respiratory tract would improve immune defenses and reduce the severity of the disease. According to the authors of this research, this could explain “documented findings linking lower severity of Covid-19 with mask wearing“. “High levels of humidity have been proven to reduce the severity of the fluunderlines Adriaan Bac, the main author of the study, and that could be applicable for Covid-19.” High humidity in the airways stimulates mucociliary cleansing: an immune mechanism that expels mucus, and the dangerous particles it may contain, from the lungs. It also increases the production of proteins, called interferons, which fight against viruses. The researchers did not compare the level of humidity according to the type of mask. But the High Council for Public Health recommends no longer wearing homemade masks since the end of January. According to his conclusions, they do not offer a sufficient level of protection against variants of Covid-19.
