PFF2 type masks, which are equivalent to KN95 masks, offer almost 100% protection against the coronavirus, concluded a study released last week by the Max Planck Institute in Germany.
According to the authors of the study, the risk of an infected person transmitting the disease indoors at a distance of three meters is high. It takes less than five minutes for an unvaccinated person standing next to a person with Covid-19 to become infected with almost 100% certainty, the study says.
However, if both are wearing well-fitting medical masks or – better yet – FFP2 masks, the risk drops dramatically, according to researchers at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany.
“We would not have thought that at a distance of several meters it would take so little time for the infectious dose to be absorbed by the breath of a carrier of the virus,” said Eberhard Bodenschatz, director of the Max Planck Institute, in a statement.
The researchers explain that, at this distance, breathable air spreads into the air in a cone shape. Furthermore, particles that are particularly large, and therefore virus-rich, fall to the ground after a short distance in the air.
“In our study, we found that the risk of infection without the use of masks is enormously high after just a few minutes, even at a distance of three meters, if infected people have a high viral load of the delta variant of Sars-CoV-2 ”, says Bodenschatz.
The environments that most favor this type of infection are schools, restaurants and clubs, but even outdoors the risk of infection under these conditions is still high, says the study.
The study confirms that FFP2 or KN95 masks are particularly effective at filtering infectious particles from the air you breathe – especially if they are fitted tightly to the face. If both the infected and uninfected people wear well-fitting FFP2 masks, the maximum risk of infection after 20 minutes is unlikely to be more than one in a thousand, even at the shortest distance, the researchers say.
If the masks are tightly fitted, the chance of infection increases to about 4%.
The study also confirms the intuitive assumption that, for effective protection against infections, the infected person must wear a mask that filters as best as possible and fits well on the face.
How masks protect against Covid-19, study says
The study used a mannequin to demonstrate how the respiratory cloud and possibly coronaviruses spread in different settings.
Without a mask, many potentially infectious particles disperse in the room, researchers say. Surgical masks already significantly reduce the amount, even if they don’t fit well.
Well-fitting FFP2 or KN95 masks can provide even more protection.
Although Max Planck researchers’ analysis shows that FFP2 face-tight masks provide 75 times better protection compared to tight-fitting surgical masks and that the way the mask is worn can make a big difference, medical masks significantly reduce the risk of infection compared to a situation without any oral or nasal protection.
“That’s why it’s so important for people to wear a mask during a pandemic,” said Gholamhossein Bagheri, head of the research group at the Max Planck Institute. “Our results once again show that wearing masks is a very good idea,” said Bodenschatz.
Reference: CNN Brasil
