Duke University study shows effectiveness of different face masks

Posted at 1:49 PM, Aug 11, 2020
and last updated 2020-08-11 18:05:27-04

BOISE, Idaho — When being out in public, it is easy to see almost everyone is wearing a different type of mask. So, Duke University recently conducted a studyfocused on just how adequate each different cover is against COVID-19.

One of the authors and Associate Professor of Medicine at Duke University, Dr. Eric Westman, says this is one of the first studies that focus on masks made for community use, such as cotton masks or bandanas.

Researchers tested 14 different types of commonly used masks that they have seen used in communities.

“We wanted to figure out which ones were really good and which ones were bad. We wanted to make sure that the product being made among the volunteers and the not commercially made ones, was actually good,” Westman says. “What we looked at was just the speaking, and it turns out that just by speaking, we emit these partials we can’t see.”

A laser, camera, and black box were used to see the particles. A subject would then say, “stay healthy people” five times, and the number of particles dispersed would be reviewed.

“You could see the particles accumulating without any sort of face covering,” Westman says.

Authors of the study say face masks used in hospitals such as three-layer surgical masks or N95 masks without valves are the safest option. Due to those being limited, a cloth mask is the next most reliable option.

Bandanas, fleece, or gator masks are not as useful as you might think.

“The drop off when we went to bandanas, a two-layer triangle around the face, and then the neck fleece or gator or buff. These didn’t work well,” Westman says.

These types of masks did not stop the spread of particles. They have the chance to make the spread worse.

“The neck fleece didn’t stop the particles at all, and it made the large particles into small particles so it might make it worse. Suppose we are trying not to have air-born particles that stay in the air awhile. And again, this really is one of the first looks at how these community masks and homemade masks might work,” Westman says.