Wearing a mask can help protect you if no one else is wearing it
One a federal judge in Florida brought down the US Centers for Disease Control and Prevention (CDC) public transport mask duty on April 18, which means that people no longer have to wear masks on public transport in most cases.
When the mission is over, some public health Experts have advised people to continue wearing masks on public transport and in other crowded indoor areas, even when others around them are not. People at high risk for severe COVID-19 — including those who are immunocompromised or have chronic medical conditions — may want to continue wearing a high-quality mask even when doing so is not recommended for everyone in their areaunder CDC guidance.
But is “wearing a one-way mask” – or wearing a mask even when no one is around – really enough to protect you from getting infected with SARS-CoV-2, the virus that causes COVID-19?
“A one-way mask is definitely better than nothing — but she says it’s also not as good as a general-purpose mask,” says Emily Sickbert-Bennett, director of infection prevention at UNC Medical Center. .
Masks work in two different ways: they contain the wearer’s germs and filter out the germs of others. If two people are wearing masks to trap some of the particles they breathe out, there will likely be fewer germs floating around in their shared air, and both people will have a lower risk of getting sick. “One of the key things you want to do in infection control is block the source,” said Kimberly Prather, an aerosol expert and chair of the department of atmospheric chemistry at the University of California, San Diego. “Never leave it in the air in the first place.”
If one person does not wear a mask and freely breathes out germs, all responsibility for protection rests with the other person’s mask. Although cloth masks and surgical masks provide some protection in this case, respirators like N95s and KN95s designed to filter out almost all particles, making them the best and most protective option for one-way respirators.
A model study published in a magazine PNAS in December 2021 estimated a person wearing a mask to get sick after talking to a non-masked person with COVID-19. Someone wearing a surgical mask has up to a 90% chance of becoming infected after half an hour (even when sitting about 5 feet away from a sick person), while those wearing a mask have about a 20% risk after an hour. adequate, the researchers estimate. If both the sick person and their companions are wearing respirators, the risk of infection drops to just 0.4% after an hour.
In other words, wearing a high-quality mask provides significant protection even when others aren’t — but wearing a two-way mask is even better, the study found.
A relatively small CDC study published in February provides some real-world data. The results showed that people who said they always wore a respirator in public places in their home were 83% less likely to test positive for COVID-19 than those who said they didn’t wear a mask indoors. People wearing surgical masks were 66% less likely and those wearing cloth masks were 56% less likely to test positive. Of course, people wearing face masks in public are likely to be more cautious about COVID-19 in general than those wearing masks indoors — and the data are self-reported — but the CDC authors still argue that masks help prevent people wearing masks from getting sick.
Masks like the N95 are the best protective masks on the market, but they only work when they fit properly. Your respirator should create a seal over your face, with no openings for air to get in. (Experts say that a good way to test this is to bring your hands close to your face and breathe in and out. If your mask fits snugly, you won’t feel any air coming out.)
There are also a lot of respirators for sale, so be careful when buying. Packaging for real N95 will be marked with an approval label from the National Institute of Occupational Safety and Health (NIOSH). The N95 non-profit project also has Instructions on how to find authentic respiratorsand a White House website direct people to where to find free N95 masks in their area.
If you don’t want to wear a mask but still want to wear one in public, you can make surgical masks more effective with a few simple tweaks, says Sickbert-Bennett. Tie the earcups for a better fit and use the metal rod at the nose to help the mask conform to the contours of your face. (Sickbert-Bennett recommends using both hands to slide the bar across the sides of your nose instead of pinching it, which can create a spot at the bridge of your nose to let out air.) If you want to wear a mask with fabric, layer a surgical mask over it for extra protection.
Besides Update on COVID-19 vaccination“Having a mask that fits is the best thing you can do” to protect yourself in public places in your home, says Sickbert-Bennett. But it is not easy. If you’re around someone who has COVID-19, a lot of factors can affect whether you’re infected: how contagious they are, if they are covered with a face covering, How much protection do you have from vaccines and previous exposures?How strong is your immune system, etc.
While one-way masking isn’t perfect, Dr. Monica Gandhi, associate director of the University of California, San Francisco’s division of HIV, infectious diseases and global medicine, thinks it’s a strategy. relevant now that highly effective vaccines and drugs are widely available in the United States and available therapies for people who do not respond well to vaccinations.
Gandhi said that masking tasks have proven to be imperfect. Some people wear masks incorrectly or don’t wear masks at all, while others (initially at the urging of US public health officials) chose a lower quality cloth mask. She thinks it’s time to recognize those shortcomings, move away from the missions, and instead encourage those who want extra protection to wear high-quality respirators.
But the most vulnerable members of society may face an increased risk of infection when masks are turned off in most common indoor spaces. Children under 5 years old are not allowed vaccination not yet, and older people and people with weakened immune systems can still be cautious about getting infected. “It’s a much bigger burden today for people at high risk,” says Prather.
Prather said she would feel more comfortable when the mask mandates were over if the US had better standards for indoor air quality measurement, proper ventilation and public air filtration. in the home. Cleaner indoor air could act as “a mask for the whole room,” reducing or even eliminating individuals’ actual need for masks, she said.
However, until and unless that happens, wearing a high-quality mask in an indoor space is a good way to help protect yourself — even if others aren’t.
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