By CBSLA Staff

LOS ANGELES (CBSLA) — Consistent wearing of face masks by a majority of the population have emerged as the best way to slow the spread of coronavirus, but not all face coverings are equal in effectiveness, according to a new study by Duke University researchers.

(credit: Science Advances)

The study tested 14 different face masks or mask alternatives with the same protocol – a control trial where a speaker wore no protective covering and another test where a speaker was recorded repeating the sentence, “stay healthy, people” five times.

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Non-valve N95 masks, the type typically worn by doctors and healthcare workers caring for COVID-19 patients, were found to be the most protective face coverings. Hand-made cotton face coverings were also found to eliminate a substantial amount of the spray that scientists say are responsible for spreading the virus.

However, bandannas and neck fleeces – such as balaclavas and neck gaiters – were found to not block droplets much as at all.

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“They were no good,” Duke physician Eric Westman said in a statement released by the university. “The notion that ‘anything is better than nothing’ didn’t hold true.”

The ineffectiveness of neck gaiters may be due to the way they function. They are typically worn around the neck, then pulled up to cover the nose and mouth.

“It’s a combination certainly of stretchiness of the material and the material potentially being very thin,” Duke University professor Martin Fischer said.

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The out-breathing valve of a breathing protection mask of the category FFP3 is checked by an employee at the production line at Moldex-Metric, a German producer of working protection clothes, in Walddorfhaeslach, southern Germany, on March 12, 2020. – Due to the outspread of the coronavirus COVID-19, there is a strong demand on medical protective, especially of protection masks. (Photo by THOMAS KIENZLE/AFP via Getty Images)

Neck gaiters aren’t the only type of face coverings that have been found to be ineffective at suppressing droplets expelled by talking, coughing or sneezing. Face masks with valves have been banned by Delta Airlines, which requires all passengers to wear masks at all times when not eating or drinking. The CDC has also issued a recommendation against wearing such masks, because even though they protect the wearer, they allow exhaled respiratory droplets to reach others and potentially spread COVID-19.