In the past few weeks, there has been a change in trends regarding wearing protective equipment for coronavirus as many people have started switching to face shields in the place of face masks. However, many health experts were not sure if the shields can indeed be used as an alternative and are just as effective as the conventional face coverings recommended by all health agencies.
Now, a new study conducted by researchers at Florida Atlantic University shows that the doubts regarding the use of face shields were indeed valid.
The findings of the study, which were recently published in the journal Physics of Fluids, show that while a shield can offer a level of protection and is better than wearing no equipment at all, it is not sufficient, and face masks are much for effective in doing so.
In fact, people who choose to wear shields over a mask can actually be putting themselves as well as other people around them at higher risk of coronavirus as they only stop forward motion of the particles released into the air upon talking, sneezing, coughing, or any other similar activity.
The researchers explained that “We observe that face shields are able to block the initial forward motion of the exhaled jet; however, aerosolized droplets expelled with the jet are able to move around the visor with relative ease,”
“There is a possibility that widespread public adoption of the alternatives, in lieu of regular masks, could have an adverse effect on ongoing mitigation efforts against COVID-19.” They added.
In addition to wearing shields, masks with valves were also seen to be not as effective as the normal masks recommended by the U.S. Centre for Disease Control and Prevention.
During the visual presentation done during the research, it was confirmed that while both masks with valves and face shields blocked particles initially, several aerosolized particles were released into the air later.
Therefore, the researchers concluded that “Overall, the visuals presented here indicate that face shields and masks with exhale valves may not be as effective as regular face masks in restricting the spread of aerosolized droplets,”
The leading investigator of the study and an assistant professor at Florida Atlantic University, Siddhartha Verma, explained that masks stop all particles released from the mouth and the nose including the smaller aerosolized particles but face shields are not able to do that.
More specifically, if the particles are ten microns or even smaller than that, shields are not really effective as they can escape from below the shield or the sides.
On the issue of face shields, the CDC recommends that people stick to the previously recommended fabric masks for the effective prevention of coronavirus as it is not yet known that what level of protection can they actually offer.
Health experts, in addition, also suggest the same. If anyone chooses to wear a shield, wearing it along with a face mask can be helpful and can help with extra protection from the coronavirus but wearing it alone is not effective.