By now people understand that they have to use face coverings to protect themselves and others from the coronavirus. But the medical experts are still divided on what is more effective as a face covering, a face mask, or a face shield.
Face masks make a barrier to stop respiratory droplets from going into the air and towards other people when a person wearing it coughs, sneezes, talks, or shouts. The coronavirus usually spreads among people who are closer than 6 feet to each other, so the face masks help when people are close without any social distancing.
While on the other hand face shields create a barrier that stops people from touching their faces. Their added advantage is that they are reusable by simply disinfecting them after each use. Moreover, they are comfortable to use and also make visible people’s expressions and lip movements. Further, people need to lower their face masks when they need to talk but with face shields, it’s not required.
Dr. Amesh Adalja a senior researcher at John Hopkins University Center and whose work is focused on pandemic preparedness, biosecurity, and emerging infectious diseases said that there is a possibility that face shields are better than homemade or any other masks. The reason he believes is that it not only prevents transmission of the virus but it also provides added protection to the face.
Adalja added that with face masks people may need to constantly adjust it, touching their face in the process and also increasing the risk of transmission from hands. But with face shields, you cannot touch your face as it creates a barrier.
Dr. Eli Perencevich a professor at the University of Iowa Carver College of Medicine and an infectious disease physician believes face shields should not only be worn by health workers but also the general public.
According to Dr. Eli face masks only prevents people from spreading the virus while face shields also protect the wearers from infection. He said this while referring to a study that says face shields reduce exposure to influenza virus.
The study, which was published in the Journal of Occupational and Environmental hygiene in 2014, used cough simulators to analyze the effectiveness of face shields in blocking aerosol droplets. It was found that the face shields were able to reduce exposure to respiratory droplets by 96 percent.
William Lindsley, who published the study and is also a research biomedical engineer, believes that the general public should prefer face masks over face shields. According to him, a face mask will do a better job against small particles than a face shield, because as the particles get smaller, they can make their way inside the face shield and be inhaled.
Another thing to consider while choosing to wear either a face mask or a face shield is that in warm weather conditions people will find face shields cooler to wear than face masks. Face masks are also known to cause breathing difficulty for some, can also irritate the skin and make glasses foggy.
Centers for Disease Control and Prevention (CDC) does not recommend the use of face shields for routine activities and won’t recommend it to be used as a substitute to face masks.
The experts are divided on whether a face mask or a face shield is better but a general suggestion is that both of them are effective depending on the environment of the wearer.