Share this on FacebookAugust 17th, 2020 | by NEWCA
ConstructionDive reports about a new Duke University study that found bandanas and gaiters—quite popular on many jobsites—are among the most ineffective face coverings at slowing or stopping the spread of COVID-19.
Published by the American Association for the Advancement of Science, the study looked at a wide range of masks and mask materials, including N95, surgical, cotton, fleece and bandanas, among others. One key finding was that the popular spandex gaiters and cotton bandanas are either no better—or potentially worse—than going maskless.
Using optical imaging technology, the study measured the spread of respiratory droplets during regular speech and found large disparities in masks’ containment abilities.
The study did not directly address concerns about the Coronavirus’ ability to pass through the naturally occurring pores of most masks due to its microscopic size.
From the ConstructionDive:
“Four two-layer cotton pleated masks, a one one-layer cotton pleated mask and a knitted mask were found to be relatively helpful at minimizing spray, coming in at less than 0.4 relative droplet count.
“The study also highlighted the types of face coverings that are not helpful in mitigating droplet spread and brought up many considerations for workers on construction jobsites, especially those who prefer to wear lightweight masks such as neck gaiters. These were found to disperse the largest droplets into a multitude of smaller droplets.
“’Considering that smaller particles are airborne longer than large droplets (larger droplets sink faster), the use of such a mask might be counterproductive,’ the researchers wrote.
“Furthermore, the study found that valved N95 masks, which are commonly used in construction, can decrease the protection of those surrounding the wearer.
“’Such a valve allows air to move from the wearer’s mouth and nose through the mask without going through the main filter,’ the study said. ‘While this may make exhaling easier, at the same time, it may permit viruses to get on through to the other side.’”
You can read more at ConstructionDive here and the Duke University study is available here.