To paraphrase Hamlet’s soliloquy, that is indeed the question we now face during this phase of the coronavirus pandemic. There are those amongst us that would have us all believe that the universal wearing of a face mask will save thousands of lives. However, instead of looking at this as the political statement it seems to have become, let’s take a look at the reasoning beyond this to see if a universal mask mandate really makes sense. Let’s look at some of the facts and not the political fodder that mask wearing has become for some in the media and politics.
First, let’s take a look at viral particle size and mask filtration characteristics. The SARS-CoV-2 viral particle known as a “virion” is about 120 microns in diameter although it probably varies from 60 to 140 microns. Cloth facial masks which most people are wearing are too porous to either catch the virus on exhalation if you have the virus or prevent you from inhaling it if you don’t.
Second, only a mask that has filtration characteristics of an N-95 mask or better has a chance of stopping such small particles. The “N” in N-95 stands for “Not Oil Resistant” and the “95” means that it will filter out 95% of particles 0.3 microns or greater in size. Without getting into the murky details of particle filtration science, suffice it to say that the SARS-CoV-2 virus itself may be smaller than the actual N-95 particle filter size, but the virus usually travels attached to larger particles or conglomerates of viral particles that are consistently snared by the filter. In addition, though the actual individual viral particle size may be smaller than the filtration or pore size of the N-95 material, there are other mechanisms that promote capture of the viral particle by an N-95 mask. For example, electrostatic attraction may promote attachment of the virus to the fibers of the mask and the erratic movement of the viral particles may also help to ensnare these viral particles in the filter material. In any event, the N-95 mask is pretty good in filtering out the virus if the filtration material is intact and if worn properly.
Third, a cloth mask may retain droplets of expiratory secretions, but these droplets are not going to be airborne for prolonged periods like an aerosol would be likely to do. So if a person is infected, a cloth mask may be of some benefit in limiting spread of the virus due to droplet transmission in a close environment. For example, if a carrier of the virus happens to sneeze or cough up droplets, then these infected droplets may be retained in the cloth fibers of the mask thereby limiting the spread of the virus to others. However, a cloth mask will not stop the transmission of aerosolized viral particles that may also be launched by a cough or a sneeze. Likewise, on the receiving end, a non-infected person wearing a cloth mask might be somewhat protected from the large droplets launched by a infected person with a cough or a sneeze, but a cloth mask will not protect him from aerosolized viral particles which will pass through a cloth mask. Bear in mind that when an infected person coughs or sneezes there is both droplet and aerosolized transmission of the virus.
Fourth, many people now seem to feel it is necessary to wear a mask, cloth or otherwise, when they are in the wide open spaces walking, running, or riding a bike with no one within yards or miles of themselves. This may make them feel more comfortable and protected, or it may make them feel that they are better neighbors because they are protecting others even if they themselves are asymptomatic. However, the reality of such protection is very questionable because the need for a mask of any kind under these circumstances is questionable. My personal feeling is that using a mask of any kind in this setting, and I emphasize “in this setting” is unnecessary and tends to foster paranoia, or at least unnecessary worry, at a time when we should be trying to bring things back to normal.
So my suggestions regarding mask wearing are:
- Wear an N-95 type mask if you are in an enclosed area where you cannot maintain a good degree of social distancing. This affords the best degree of protection both for yourself and others.
- If you don’t have an N-95 mask and can’t maintain social distancing, than by all means use a cloth mask at the very least. It will provide some limited degree of protection.
- If you are in the wide open spaces for a walk, jog or a bike ride, then wearing a mask of any kind seems unnecessary. It’s time to start bringing things back to normal.