According to an August report in Nikkei Asian Review, the Japanese supercomputer Fugaku modeled the effectiveness of face shields in blocking the cough of a person wearing a face shield. The model showed that larger droplets—of 50 microns or more—stuck to the inner surface of the shield, but the smaller droplets—20 microns or smaller—were able to creep through the gaps around the shield. The study also looked at the effectiveness of cotton, polyester, and non-woven masks in intercepting a cough. The non-woven mask was found to be the most effective. However, all three face masks outperformed the face shield, blocking at least 80 percent of viral spray.ae0fcc31ae342fd3a1346ebb1f342fcb And this isn’t the only study to conclude that face shields are not a useful form of protection. A Sept. 1 study published by Physics of Fluids simulated coughing and sneezing from a mannequin’s mouth and used laser light to visualize the droplets expelled. This study found that face shields were only able to block the “initial forward motion of the exhaled jet.” Following the initial jet, the droplets from the cough or sneeze were able to easily move around the visor. RELATED: For more up-to-date information, sign up for our daily newsletter. Although the Centers for Disease Control and Prevention (CDC) has already posted guidance advising that they do not recommend the use of a face shield as a substitute for a mask, that has not been enough to dissuade some people. But with these two studies as further evidence, it seems clear that face shields are one of the worst face covering options when it comes to trying to protect yourself from COVID. And to find out when you can ditch your face covering entirely, Dr. Fauci Says This Is When We May Be Able to Stop Wearing Masks.
