A scientific study takes stock of the effectiveness of different types of masks. The observation is clear: they do not all have the same effectiveness.
A scientific studies takes stock of the effectiveness of different types of masks in blocking salivary droplets and protecting others from possible infection with coronavirus.
After several months of debate, the face mask to prevent the spread of the coronavirus is now a consensus.
Associated with barrier gestures, which should not however be abandoned, the mask is effective in slowing down the spread ofepidemic.
In particular, it allows the wearer not to diffuse droplets of saliva in the ambient air at all costs when speaking, sneezing or coughing.
In a new study published Aug. 7 in the journal Science Advances, researchers from Durham (North Carolina, United States) compared 14 different masks… fabric masks, or even a simple bandana.
The team put together a very simple installation, consisting of a black piece, a box, a laser, a lens and a smartphone camera.
A volunteer then entered the facility, first without a mask and then with different types of face masks, and pronounced the sentence “stay healthy people” (“stay healthy”).
This method allowed the researchers to observe the number of droplets suspended in the ambient air just after the individual spoke.
- Unsurprisingly, the study reveals that the n95 mask (without valve) proved to be the best to avoid the projection of droplets (The N95 mask is a protective mask against particles with a filter, meeting the filtration classification from the US agency NIOSH).
- It is closely followed by the surgical masks (number 14 in the photo below) worn by the nursing staff.
- Polypropylene and cotton-polypropylene masks also performed well.
- Even fabric masks, especially cotton, have proven to be quite effective.
On the other hand, bandanas and other makeshift fabrics, not intended for such use, have proved ineffective or even dangerous, as they are liable to further disperse the droplets of saliva in the surrounding air, transforming large drops of saliva into small particles.
According to the study, these makeshift devices could even be worse than wearing nothing at all!
“ We have confirmed that when people talk, small droplets are expelled, so the disease can be spread by talking, without coughing or sneezing “, Commented Martin Fischer, co-author of the study in a statement:” We have also seen that some face coatings have done much better than others in blocking the expelled particles. ”.
(Source : Health Magazine)