Are masks effective against coronavirus?

Unchallenged

Masks can prevent the spread of coronavirus, even if they don't protect the wearer from contracting it.

Lydia Bourouiba, an associate professor at MIT, has researched the dynamics of exhalations and found that exhalations cause gaseous clouds that can travel up to 27 feet (8.2 meters). Masks can reduce the distance travelled by gaseous clouds and the amount of droplets in them.

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