The masks are not equal when it comes to protecting the wearer against the COVID-19, but all of them, even the covers-face to craft the simplest, would prevent at least some of your cough to land on your neighbor.
Confined to his home, Matthew Staymates, an engineer at a federal research institute u.s., has tested 26 covers-different faces that are designed with common materials such as flannel, cotton or polyester. Using sophisticated equipment for viewing the flow of air borrowed of his work, he filmed himself in the process of coughing in each of them.
It has been demonstrated that all had blocked a part of the cloud of exhaled air that could potentially carry infected droplets. However, the experience was not the virus particles themselves.
“Even the cover faces the most simple […] prevent a large part of your cough to land on someone else,” says Mr. Staymates on his blog, where you can see the video results.
This is why everyone should wear a mask or covers the face in public, especially in the vicinity of the other, he insists, while noting that a good cover-face is well fitted, breathable, it covers the mouth and nose, and that it is made of a few layers of a fabric, tightly woven.
In another study published in the Journal of Hospital Infection, scientists from the University of Arizona used a mathematical model to predict the protection offered by several types of masks, but this time to the one who wears the mask.
Not surprisingly, the masks professionals such as the N95 and his cousin even more powerful, the N99, are the most secure, but some solutions craft provide a defense surprisingly acceptable.
The vacuum filters, which may be inserted in the pockets of some of the masks in fabric, would reduce the risk of infection by 83 %, if it is exposed to coronavirus in a contaminated environment for 30 seconds. The reduction would be 58% for an exposure of 20 minutes.
The cover faces are made of a scarf, themselves, decrease the risk of infection by approximately 44 % after 30 seconds of exposure, and 24 % after 20 minutes, while the cotton t-shirts are only slightly more effective than not wearing anything at all.
– With the collaboration of the QMI Agency