- Sep 22, 2007
- Reaction score
I think understand the difference regarding materials. My point is just that the fit and resultant seal is another important variable.I'm far, far from an expert on this area, but my understanding is that most masks are made from one of three materials.
There's metlblown, which is what you'll find in an N95 mask. Then there's spunbond/ spunbel, which is what you'll find on medical masks and most filters. And then there's cloth masks.
Meltblown is the gold standard, but there's a huge shortage of the stuff. The machines that make meltdown are in short supply and they take a lot of time and money to build. But if you can get a good seal on an N95 mask with meltblown, you can filter up to 95% of particles.
Then there's spunbound/ spunbel, as you'd find on a medical mask. This New York Times article says medical masks will filter up to 60 to 80 percent of droplets. So not as good as N95's meltblown, but better than cloth.
Finally, cloth filtration really varies, as it depends on the material. But it's not as good as the others because it's a woven material, which has tiny holes between the threads. Meltblown and spunbond are nonwovens.
So I think it's true that medical masks don't give you as much filtration as an N95, but it's better than not wearing a mask or wearing a woven mask. How a medical mask compares to a pouch-held filter, I don't know.
And so my question is, how much protection would a mask with poor fit give (to oneself and others), even if it had good material (whether meltblown or spunbond)? More specifically: If N95s give relatively little protection when they don't have a great seal, then how much protection would a cloth mask with a filter insert or a loose medical mask give? My guess is that the air would take the path of least resistance, and thus largely enter and exit where there were gaps or where the filter doesn't extend.
This pic illustrates what I meant regarding gaps or looseness around the edges of a medical mask:
Compare that fit to the Proper Cloth one that you posted earlier. Would a loose-fitting medical mask be better protection than a well-fitting, 2-3 layer cloth mask, with or without a filter?
The Mayo clinic mentions this looseness as well as medical masks' intended purpose of protecting one from splashes and droplets (and large aerosols):
Also called a medical mask, a surgical mask is a loose-fitting disposable mask that protects the wearer's nose and mouth from contact with droplets, splashes and sprays that may contain germs. A surgical mask also filters out large particles in the air. Surgical masks may protect others by reducing exposure to the saliva and respiratory secretions of the mask wearer.
I'm definitely not saying we shouldn't be wearing masks. I just wonder how much protection each type gives. Personally, I just wear a cloth mask that doesn't have many gaps, mainly to protect others. And once a month I'll wear a N95 to go to Costco where it's crowded and I want to give myself, and potentially others, more protection. But maybe a medical mask or a cloth mask with a filter would be better.
Since we'll be wearing masks for the long term, as Fok mentioned, it'd be great if scientists could conduct some comprehensive studies on this.