Outdoor concerts, for example, often bring people together for several hours and carry more risk, Popescu says. “Ventilation is important and there is great ventilation to the outside, but there’s only much that can do when you’re side by side with hundreds of people for hours, screaming and screaming,” she says.
But i’m healthy and i’m taking risks
In addition to the guidelines above, there are two basic factors to consider when deciding whether or not to wear a mask: protect yourself and protect others. Unless you have been completely away from everyone and tested negative for Covid that morning, you have to assume that there is still a chance that you are infected, and therefore that you could infect. others.
If you are around people at high risk of infection or serious illness, such as immunocompromised, unvaccinated children, the elderly, or someone at high risk, it is safer to wear a mask to protect them from you. . In places like grocery stores and drugstores, where almost everyone has to go even if they are in a high-risk group, the most thoughtful thing to do is always wear a mask, regardless of the rates. transmission, because you don’t know if you will be surrounded by vulnerable people.
In places like restaurants, bars, and home meetings where you don’t have to wear a mask, your decision is more on your own risk tolerance level. What risk of exposure are you comfortable with in exchange for not wearing a mask?
“There is a framework of interventions that are important in preventing you from catching Covid, and then there are the risk factors people have for a bad outcome,” says Anthony harris, epidemiologist at the University of Maryland School of Medicine. “If you combine these two hierarchies with someone’s own subjective risk assessment, that’s how they should make decisions. There is neither black nor white.
In addition to local infection rates, there are several factors you should consider:
- How likely are you to develop serious illness if you have a breakthrough infection? If you’re over 70 or are immunocompromised, you may fare worse with a breakthrough infection even if it doesn’t kill you.
- Are others around you vaccinated or not? (If you don’t know, assume some aren’t vaccinated.)
- How close are you to others?
- How long have you been there or have you been close to others?
- How big is the area?
- Is the area well ventilated?
The quality of the masks also matters
Also, keep in mind that not all masks are created the same.
“I encourage people to focus on using a quality mask, which is about fit and filtration,” Popscu says. “Ensuring the quality of masks becomes all the more important indoors. “
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, has been advocating for months for Americans to wear better protection than fabric masks, the quality and effectiveness of which vary greatly. In the first half of 2020, public health experts discouraged the general public to wear N95, KN95 and similar respiratory masks so that healthcare workers have enough. But now, Osterholm says, healthcare workers and other professions that need respirators have plenty of them. There is no reason why the general public should not regularly wear these much more effective masks too much. If nothing else, pair a cloth mask with a medical mask.
Ventilation, Ventilation, Ventilation
Of the above factors, the latter is among the most important, says Alex huffman, an atmospheric chemist who studies bioaerosols at the University of Denver. The reason “the outside is considerably safer than the inside” is that virus particles exhaled by others have no chance of accumulating. They just float up and away. Inside, it’s a different story.
Aerosols containing viruses that an infected person exhales “mix into the room and can build up in concentration if there is insufficient ventilation,” Huffman explains. In a stagnant room where aerosols accumulate, it takes fewer breaths to inhale enough virus to become infected. The volume of the room also matters, he says.