Popescu said, for example, outdoor concerts often make people huddle together for several hours and take greater risks. “Ventilation is very important, the ventilation outside is good, but when you are side by side with hundreds of people for hours and yelling, it can only do so much,” she said.
But i am healthy and adventurous
In addition to the above criteria, there are two basic factors to consider when deciding whether to wear a mask: protecting yourself and protecting others. Unless you are completely away from everyone and your Covid test was negative that morning, you must assume that you are always at risk of being infected and therefore you may infect other people.
If you have people at high risk of infection or serious diseases (such as people with weakened immune function, unvaccinated children, the elderly, or people with high-risk diseases), it is safest to wear a mask to protect them from you of. In places where almost everyone needs to go, such as grocery stores and pharmacies, even if they belong to high-risk groups, regardless of the local transmission rate, consider wearing a mask, because you don’t know you will be with vulnerable people.
In places where you don’t need to wear a mask, such as restaurants, bars, and family gatherings, your decision is more up to you Risk tolerance. In exchange for not wearing a mask, how much exposure risk can you bear?
“Having an intervention framework is important to prevent you from contracting Covid, and then there are risk factors for people to cause bad outcomes,” said Anthony Harris, An epidemiologist at the University of Maryland School of Medicine. “If you combine these two levels with someone’s own subjective assessment of risk, this is how they should make a decision. There is no black and white.”
In addition to the local infection rate, you also need to consider the following factors:
- If you have a breakthrough infection, how likely are you to get a serious illness? If you are in your 70s or have a weakened immune system, even if it does not kill you, it may be worsened by a breakthrough infection.
- Has anyone else around you vaccinated or not vaccinated? (If you don’t know, suppose some people have not been vaccinated.)
- How close are you to others?
- How long have you been there, or how long have you been close to others?
- How big is the area?
- How is the ventilation in the area?
Mask quality is also important
Also keep in mind that not all masks are created equally.
“I encourage people to focus on using quality masks, which are related to fitting and filtering,” Popscu said. “Ensuring the quality of masks becomes more important indoors.”
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, has been advocating Americans to wear Better protection Compared with cloth masks, its quality and effect are very different. In the first half of 2020, public health experts Discourage the public Wear N95, KN95 and similar respirator masks so that medical staff have enough. But now, Osterholm says, there are many medical staff and other occupations who need respirators.The public has no reason not to wear these often More effective masks and also. If nothing happens, please pair the cloth mask with the medical mask.
Ventilation, ventilation, ventilation
Among the above factors, the last one is the most important, say Alex Hoffman, An atmospheric chemist who studies bioaerosols at the University of Denver. The reason “outdoors is much safer than indoors” is that virus particles exhaled by other people have no chance to accumulate. They just floated up and left. Being indoors is another matter.
Hoffman said that virus-containing aerosols exhaled by infected persons “will mix into the room and gather if there is insufficient ventilation.” In a lifeless room where aerosols accumulate, it takes fewer breaths to inhale enough virus to be infected. He said that room capacity is also very important.