Virginia Tech’s nationally-recognized expert in the airborne transmission of viruses, Charles P. Lunsford Professor Linsey Marr, explains the limitations of face shields when it comes to protection against Covid-19. Marr shared her insight during a live streamed conversation with President Tim Sands on Aug. 19.
All the studies that we've seen, research that my group has done, and others, show that face shields are good at stopping those large droplets, the spit balls, of course now anyone can, any kid could probably tell you that. And then, but it doesn't do anything about the aerosols. Imagine if you're smoking or that you're in a room filled with cigarette smoke, is that face shield going to protect you from breathing the smoke? No, it's just going to go around the sides. So face shields are recommended as kind of on top of a mask if you want greater protection for your eyes, for example, if you're going to be close to someone who's unmasked, it can provide extra protection. Otherwise, it's a bit of the, I'd put it in the theater category where it's something that looks good but doesn't actually achieve that much for how this virus is transmitted.