We've all been told to wear face masks to reduce the spread of coronavirus, but it turns out the material your mask is made of may affect your risk, a new study suggests.
An N95 mask, which filters out nearly all particles both large and small, reduced the odds of transmitting COVID-19, the disease caused by the virus, the most.
But some masks were actually worse than not wearing a mask at all because they turned large potentially infected droplets into smaller droplets than can linger in the air longer.
The team, from Duke University, says the findings provide evidence that not all face masks are created equally and can give Americans advice on what to and not to wear when going out in public.
For the study, published in the journal Science Advances, the team looked at 14 different types of face coverings.
Researchers cut a hole in front of a black box so a speaker can talk into it and covered it with a thin sheet of light from a laser beam.
Next, they placed a cell phone camera in the back.and recorded the respiratory droplets that cut through the laser beam when they talk.
A person spoke towards into the hole saying the phrase 'Stay healthy, people', while wearing the different types of coverings.
1. Three-layer surgical mask
2. N95 mask with exhalation valve
3. Knitted mask
4. Two-layer polypropylene apron mask
5. Cotton-polypropylene-cotton mask
6. One-layer Maxima AT mask
7. Two-layer cotton, pleated style mask
8. Two-layer cotton, Olson style mask
9. Two-layer cotton, pleated style mask
10. One-layer cotton, pleated style mask
11. Gaiter type neck fleece
12. Double-layer bandana
13. Two-layer cotton, pleated style mask
14. N95 mask, no exhalation valve, fitted