Using a green laser pointer and a mannequin’s head, Florida Atlantic University researchers have created stunning visuals that show how different face masks stop respiratory droplets from spreading following a cough or sneeze.
Not only does the research clear up some of the confusion as to which type of face mask is the best, the researchers believe it could also help convince people to consistently don their face masks while in public.
Which Type of Face Mask Is the Best?
For their study, the FAU team connected a fog machine and manual pump to a mannequin’s head.
Using this rig, they could eject water vapor from the mannequin’s mouth to emulate the respiratory droplets expelled during coughs and sneezes. With the help of an off-the-shelf green laser pointer, they could make these droplets easily visible.
The first thing the researchers did with their setup was simulate the spread of respiratory droplets in a variety of scenarios while their mannequin’s mouth was uncovered: following a light cough, a heavy cough, in a still room, and in one with a breeze.
This revealed that the droplets could travel as far as 12 feet in less than one minute, and in the still environment, they could linger in the air for up to three minutes.
Seeing Face Masks in Action
After recording how the droplets spread without any face mask, they ran the experiment again using four types of face coverings: a loose bandana, a cone-style mask, a folded cotton handkerchief, and a homemade two-layer cotton mask.
As for which type of face mask is the best, all four styles prevented the droplets from spreading farther than three feet, but the cone-style and homemade masks were most effective, limiting their spread to 8 inches and 2.5 inches, respectively.
Knowing which type of face mask is the best could convince some people who are already wearing, say, a bandana to make the switch to a homemade cloth mask, and that alone could help stem the spread of COVID-19.
“Promoting widespread awareness of effective preventive measures is crucial at this time as we are observing significant spikes in cases of COVID-19 infections in many states, especially Florida,” researcher Siddhartha Verma said in a press release.
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