We warned of this long ago, at the beginning of the pandemic, but the use of the mask alone is not sufficient to ensure safeguards against the viral spread of VIDOC-19. It must be combined with cleanliness and, above all, with interpersonal distance.
Precisely, and related to this last aspect, the National University of New Mexico has carried out some tests in which the filtration of five types of masks is compared in the case of cough or sneeze made at 1.8 meters.
Thus, the results were that with the fabric mask 3.6% of the drops were filtered. At the other end of the comparison, it was the FFP2 mask that stopped 100% of the drops.
We have to take into account that in one sneeze there are 200 million small viral particles, depending on the level of infection of the person, obviously. This helps us to get an idea of how important it is to keep the interpersonal safety distance and limit the stay in places with people as much as possible.