With so much confusion and debate about where masks must be worn, one truth remains constant: Masks work. While they work best when everyone in the room is wearing one, even if no one else wears a mask, a person who does is protected against infectious particles in the air.

The amount of protection depends on the quality of the mask and how well it fits, according to The New York Times. Health experts recommend wearing an N95, KN95, or KF94 to protect against the highly infectious BA.2 subvariant of the omicron virus which is now the dominant version of the coronavirus in the U.S.

Other factors that may affect your risk are how long you are in contact with an infected person and how well the space in ventilated. Being on a plane, for example, can increase your risk of becoming ill, even though the cabin air is filtered regularly with high-efficiency filters. A study published last year demonstrated that passengers should always be spaced as far apart as possible to minimize transmission. The researchers found that passengers sitting in the same row or one row away from someone who had COVID-19 had an elevated risk of becoming infected themselves. Wearing a mask reduced that risk by 54%.

The Transportation Security Administration (TSA) recently announced that after 14 months of required mask-wearing on public transportation, travelers can decide for themselves whether to wear a mask on flights. Hours after a federal judge struck down the federal mask mandate for public transportation, the TSA  announced it will stop enforcing the requirement. The mask mandate was due to expire on May 3.

However a recent poll showed that a majority of Americans continue to support a mask requirement for people traveling on planes and other shared transportation. The poll by The Associated Press-NORC Center for Public Affairs Research found that 56% of Americans still favor requiring people on planes, trains, and public transportation to wear masks.

Linsey Marr, an expert in virus transmission and a professor of civil and environmental engineering at Virginia Tech, said other settings can be more worrisome than planes.

“I know everyone talks about planes, but I would say buses are probably the riskiest,” she said. According to The Times, no matter what the venue, study after study found that wearing a mask reduces the potential exposure of the person wearing it. Marr advises against wearing cloth masks as they are only 50% effective in protecting against infected particles. This was good enough for earlier forms of COVID-19, but not for the more transmissible omicron variants plaguing us now.

"We have special masks called respirators, such as N95, that offer much greater protection. They're able to block 95% of particles that are either going out of your mouth or that you're breathing in," Marr told CBS Boston. "Things like the KN95, which is the Chinese version of the N95, has ear loop straps and it's made out of a special material that's very efficient at filtering out particles."

Marr also suggests using three-ply surgical masks for protection, but make sure they fit correctly.

"One way is to use some little kind of clips or toggles on the ear loops so that you can tighten it up so it pulls closer to your face," she said.

A good fit is crucial to any mask a person is going to wear, she says. For kids, comfort is also key, but keep in mind N95 masks are not designed for young children so another respirator mask might be the way to go.