Ever since our normal became apparent - the one where we're all wearing face masks every day - everyone has been asking the question: "which face masks works best for coronavirus?".
We've answered that question already - and we will stress again that face masks - whether they are linen face masks or cotton face masks - are always the second line of defence when it comes to helping limit the spread of coronavirus. Hand washing and social distancing are the most important factors.
But many people now have another question: are face shields better than mask?
Face shields are usually used in a medical context. But they are increasingly being used in Canada - everywhere from schools to grocery stores.
There are certainly some benefits to wearing face masks - they are easier to talk with, for example.
However, as with many questions asked during the pandemic, researchers believe it is too early to know for sure. Dr. Lynora Saxinger, an associate professor of infectious diseases at the University of Alberta said in an interview with Global News recently that it's too early to say whether face shields are better than masks.
Saxinger was quoted as saying:
“There are a few droplet studies but no actual viral transmission studies that I have seen that clarify whether the face shield, with an open bottom and with airflow around the shield, is as protective as a mask."
“There are no studies comparing them (face shields) to masks because most real-world data we have is from health-care workers who are wearing both masks and eye protection.”
Remember, even in a medical context, plastic face shields are rarely worn on their own. They are often used in addition to a surgical face mask.
So, are face shields better than masks?
The truthful answer is that we just don’t know at this point. There are some older studies, but none specifically so far considering the current virus we are dealing with.
One study was a 2016 review on face shields for infection control.
One of the findings of that study was that the lack of a good a peripheral facial seal, plastic face shields can allow for aerosol droplets to be transmitted. The paper suggested combining a mask and a shield.
An earlier 2014 study on the effectiveness of face shields used a coughing patient simulator.
The study found that inhalation explore decreased "immediately after the cough", however, it wasn't as effective against "smaller cough aerosol".
It might well be that we end up wearing both face shields and face masks as we continue to navigate these uncharted waters.