As we have previously discussed here, the CDC in Atlanta has recommended that people wear a cloth face cover when out in public (see footnote). A face cover is not meant to substitute for social distancing, and the recommendation that people remain at least 6 feet apart remains. Because so many people still don’t seem to understand the reason for wearing a face covering, I will go over that here. Specifically, I am trying to address people who believe they are not infected, don’t think there are sick people around them, and therefore think they don’t need to wear a mask in public.
The point of wearing a face cover or mask in public or around others who are not close contacts in the home is to limit the spread of SARS-CoV-2, the virus that causes COVID-19. To date this disease has claimed over 115,000 lives in the U.S., where there have been over 2 million cases (over a quarter of cases worldwide).
How a face covering prevents the spread of COVID-19 is simple. It is a barrier. We need that because even healthy people release moisture in the form of respiratory droplets when they breathe or talk. Some people release more droplets than others – loud talkers for example. We usually can’t see these droplets because they are so small, from 0.1 to 1000 μm (a micrometer is a millionth of a meter). These tiny droplets tend to fly a certain distance before falling to the ground or some other target – hence the 6 foot rule. Droplets <5 μm can form aerosols and hang in the air. The droplets and aerosol may contain viral particles if a person is infected.
To be clear, although a mask or face covering is a barrier, it still does not stop all droplets. This should not lead one to think masks are useless (as I have also heard several times). We are not likely to get an infection unless we inhale or otherwise become infected with a certain number of virus particles, (likely a number in the 1000s). The point of the mask is to limit the number of particles released. It also probably helps limit the number you might breathe in, or at least block a few droplets flying at you.
Now, back to those who think they are healthy, and don’t see sick people around them. I hope they are all healthy, but the truth is there are asymptomatic carriers of this infection who can spread disease and not know they are infected. As I previously discussed here, if someone is infected with the virus that causes COVID-19, it can be up to 14 days before they show symptoms (the average time to symptoms is 5 days). However, they often start shedding virus in as little as 2 days. Thus, they are “presymptomatic,” spreading disease, and don’t know they are ill anywhere from 3-12 days. And, there are those who become infected, shed virus, and never develop symptoms. Wearing a mask would at least limit their ability to unknowingly make someone else sick.
Unless you have just been tested, you don’t know whether you are infected. You can’t tell just by looking at someone if they are infected either. Thus, the only thing we can recommend for now is that you wear a mask or face covering to prevent the spread of disease. It tells others that you care about their well-being.
FOOTNOTE: The CDC recommendation regarding wearing a cloth face covering in public was for everyone except children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance.
To put on a face covering, grip the cover by the draw strings or elastic material used over the ears. It is okay to adjust to tightness around the nose, but try not to touch the material through which you will breathe. In general, try to limit touching the mask while wearing, and if you do so, use clean hands. If you accidentally touch your mask while wearing, clean your hands. Keep in mind that any cloth face cover should be washed regularly, depending on use. It follows then that any material you select should be capable of being laundered and machine dried without damage or change to shape.
There are different types of masks and facial coverings. The CDC recommends a cloth face covering for non-medical people. This should be made of cloth such as old T-shirt or a bandana. Paper surgical masks are worn by health care workers. Typically, the colored side goes out (somewhat waterproof to stop droplets from the outside), and the light side to your face (absorbent to to trap your own droplets), and the piece over the nose bends to conform to the bridge of the nose. Doctors wear these to prevent getting respiratory droplets on patients, but also to protect against droplets or other fluids. N95 masks are specialized respirators that filter particulates (95% of small particles). Wearers must be fitted, and the respirator does not work well (if at all) over a beard. Masks with one-way valves that make it easier for the wearer to exhale do not filter and do not prevent the wearer from spreading the virus-defeating the purpose of the CDC recommendation.
Wash your hands!
