Does the mask protect you from Covid if no one else is wearing it?

If I’m the only one wearing a mask in a store or other indoor location, am I really protected from infection?

Indeed, masks work best when everyone in the room is wearing them. This is because when an infected person wears a mask, most of the infectious particles that are exhaled are trapped and prevented from spreading at the source of the virus. Also, if there are fewer virus particles floating around the room, masks worn by others can block the escaped masks.

However, there is plenty of evidence that masks protect the wearer even when others around them are not wearing the mask. The amount of protection depends on the quality of the mask and the suitability of the mask. Outbreak of hotels in SwitzerlandFor example, some employees and guests who tested positive for coronavirus wore only face shields (without masks). The person who wore the mask was not infected. And Tennessee research We found that communities where masks are required have lower hospitalization rates than areas where masks are not required.

“Healthcare workers, scientists dealing with nasty pathogens, and workers who may be exposed to dangerous airborne particles at work rely on special masks like the N95 for protection. , We have found that a well-fitted, high-efficiency mask works. ” Linsey Marr, a professor of engineering at Virginia Tech and one of the world’s leading experts in viral infections.

Many laboratory studies have also demonstrated that masks protect the person wearing the mask, but the level of protection is the type of mask, the material of the mask, the setup, and particle exposure. It depends on the measurement method of.

However, the conclusion of all studies is that the mask reduces the potential exposure of the person wearing it. Here are some findings.

• One study from the Centers for Disease Control and Prevention It has been found that a standard surgical mask only protects the wearer from about 7.5% of the particles produced by the simulated cough. However, tying the loop and pushing the sides of the medical mask reduced the exposure by nearly 65%. (((Watch this video Check the “knot and tack” method. Covering the surgical mask with a cloth mask reduced exposure to simulated cough particles by 83% in a technique called double masking.

• Virginia Tech Studies We investigated how homemade masks, surgical masks, and face shields protect the wearer based on particle size. Studies have shown that most masks can block very large particles such as sneezes. However, when researchers examined the smallest aerosol particles that were the most difficult to block, protection ranged from nearly zero with face shields to about 30 percent protection with surgical masks. (The percentages in this study cannot be directly compared to the CDC Knot and Tuck study due to different test methods.) Based on the findings, Dr. Ma and her colleagues filter flexible, tightly woven fabrics. Combined with materials (such as coffee filters and surgical masks), it provides excellent protection, reduces 70% of the most penetrating particles, and can trap over 90% of larger particles. They also found that head straps or ties fit better than ear loops.

• Studying from Tokyo We tested how different types of masks protect the wearer from real coronavirus particles. This study showed that even a simple cotton mask provides some protection (17-27 percent) to the wearer. Improved performance of medical masks such as surgical masks (47-50% protection), loose-fitting N95s (57-86% protection), and tightly sealed N95s (79-90% protection).

• Many labs use mannequin heads to test masks, 2008 study Real people were used to measure how well the mask could protect the wearer from respiratory viruses. Subjects wore different types of masks with special receptors that could measure particle concentrations on both sides of the mask. In this study, cloth masks reduced exposure by 60%, surgical masks reduced by 76%, and N95 masks by 99%.

All lab research has shown that masks can protect the wearer, but how well masks work in the real world depends on how people use them consistently and at high risk. It depends on various variables such as whether or not and the infection rate. In the community. Danish research Of the 6,000 participants, half were told to wear a mask, which did not show the benefits of wearing a mask, but the survey did not show any benefit. Widely criticized Because of its poor design.

Laboratory studies have shown that high quality medical masks such as N95, KN95 and KF94 are optimal. Vaccination is the best precaution against Covid-19, but even vaccinated people are advised to avoid crowds and large groups indoors if they do not know the immunization status of others. increase. Delta variants are much more contagious than other variants, so Dr. Ma is best possible if he can’t keep a distance, is outdoors, or isn’t masked by anyone around him. We also recommended wearing a quality mask.

“If you are in a situation where you have to rely solely on masks for protection — you may have unvaccinated people, they are crowded and you know nothing about ventilation — wear the best mask for your wardrobe Yes, it’s N95, “Dr. Ma said. “Delta has proven to be much easier to infect, and vaccinated people can get infected, so you should wear the best possible mask in high-risk situations.”