By: KDKA-TV News Staff

MORGANTOWN, W. Va. (KDKA/AP) – Researchers say an experiment at WVU confirmed two masks are better than one.

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Research from the West Virginia University School of Medicine found the combination of a disposable surgical mask won under a tightly-fitting outer layer significantly improves filtration efficiency and protection.

Researchers recruited four people to wear three types of masks individually: a disposable mask and the cloth mask and gaiter that WVU gives to students and employees. They also wore the surgical mask under the cloth mask and gaiter.

The researchers found that the cloth mask worn over the surgical mask performed the best, with a filtration efficiency in a room filled with saline droplets of 84%. The surgical mask worn under the gaiter had a filtration efficacy of 81%.

Last month the Centers for Disease Control and Prevention reported the results of a lab experiment that spaced two artificial heads 6 feet from each other and checked to see how many coronavirus-sized particles spewed by one were inhaled by the other.

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The researchers found that wearing one mask — surgical or cloth — blocked around 40% of the particles coming toward the head that was breathing in. When a cloth mask was worn on top of a surgical mask, about 80% were blocked.

When both the exhaling and inhaling heads were double-masked, more than 95% of the particles were blocked, said the CDC’s Dr. John Brooks.

The study had many limitations: The researchers used one brand of surgical mask and one kind of cloth mask, and it’s not clear if results would be the same with every product. But it echoed some earlier research that suggests two masks are better than one.

The CDC also was updating its guidance to address wearing two masks. If done correctly, a cloth mask worn over a surgical mask can tighten the gaps around the mask’s edges that can let virus particles in, the CDC said.

You can learn more about WVU’s study here.

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