Among all coronavirus safety tips mask usage has possibly been the most heavily debated. There are many reasons for this, ranging from cultural to scientific. In the United States, the critical PPE shortage has also compounded this confusion. I wanted to answer several of the questions I recently received on safe mask use.
Update: you can find Kaiser Permanente’s mask FAQ here.
Mask usage updates – why do recommendations change?
There are many reasons for the change, but mask recommendations depend on:
- Risk of asymptomatic coronavirus spread: if asymptomatic people can spread virus (before they know they’re sick), encouraging everyone to wear masks can help reduce spread.
- Coronavirus community prevalence: if coronavirus is highly prevalent and spreading fast in the community, mask usage may help. Even if healthy people wearing masks provides small benefit, a highly prevalent virus makes that small benefit worthwhile.
- Are masks available or in short supply?
- Are there risks to wearing masks incorrectly? (Yes, it can result in self-infection)
We have known for months that asymptomatic individuals can still spread coronavirus during the incubation period (particularly high risk in the first 4 days). However, community prevalence has dramatically increased across the United States. This makes viral spread from asymptomatic individuals more common.
Recommending widespread mask usage thus becomes a risk-benefit comparison:
- Benefits of widespread mask usage (healthy and sick): decreased spread from coughing, sneezing, and asymptomatic people. Possibly a decreased chance of droplets infecting a healthy person wearing a mask.
- Risks of mask usage: incorrect mask usage can increase chance of self-infection. The United States has a critical mask shortage. If frontline health workers can’t wear masks, they increase the chance of spreading COVID-19 to patients.
In the United States, the CDC now recommends everyone to wear a mask in public. One of my coronavirus safety tips is hence for everyone to wear a mask in public.
If I wear a mask do I still need to follow social distancing?
This is a crucial point: no mask is 100% effective, particularly if used incorrectly. Social distancing can help pick up the slack. We should view social distancing as one of the most effective coronavirus safety interventions.
Social distancing helps overcome some of the shortcomings of incorrect mask usage. Furthermore, social distancing helps minimize the chance of virus from landing on your exposed skin or clothes. Virus on your clothes can then lead to self-innoculation when you later remove your clothes. Social distancing can be effective in reducing the chance of virus from landing on you or your clothes in the first place.
Wearing a mask is NOT a substitute for social distancing!
How are masks worn incorrectly?
Most masks are used incorrectly in the general public. In my personal experience, I observe nearly all individuals in the public incorrectly using their mask. The most common culprits are:
- Not replacing it when wet, such as sneezing in it
- Touching the mask with hands
- Dragging the mask below their chin or above their head
- Reusing the mask
- Putting the mask on incorrectly by touching the mask itself
- Not washing hands before putting on the mask
- Touching the mask when they remove it
- Not washing hands after removing the mask
All of these mistakes contribute to decreased efficiency of the mask. These also increase the chance of self-infecting with COVID-19. We may also increase the chance of blowing virus into the air around us and infecting healthy people if the mask is used when wet or not disposed of timely.
How do masks protect you from coronavirus?
Surgical masks can significantly reduce the chance of water droplets with virus (from infected people sneezing or coughing) from reaching our nose and mouth, the common entry points of the virus into our bodies. N95 respirators can prevent even smaller particles containing virus (called aerosols) from reaching our nose and mouth. These smaller particles are not believed to be a significant source of virus transmission, unless you work in a hospital.
Are cloth masks, bandanas, or DIY masks effective?
A common coronavirus safety tip! DIY masks can be very helpful if somebody is actively coughing or sneezing. This cloth material may indeed reduce the spread of respiratory droplets that would otherwise affect nearby people. However, because these masks are not constructed to a specification, we cannot guarantee their effectiveness at blocking water droplets or aerosols. They likely do provide some degree of protection. In the absence of masks, they are highly recommended for people who are coughing and sneezing. For healthy individuals, the benefit is not as clear. They likely provide a degree of protection in crowded places where there may be respiratory droplets (or aerosols) from sick individuals in the air. The great benefit of DIY masks is that they can be distributed throughout the community. The community can then donate their surgical and N95 masks to hospitals and frontline healthcare workers.
If wearing a mask near someone with coronavirus, won’t the virus land on the mask? How do you recommend removing the mask to prevent inoculating yourself?
I think one of the most important coronavirus safety tips is to learn how to properly wear a mask. This question addresses that problem very well!
You should never touch the mask itself with your hands. Before and after wearing the mask you must wash your hands. This is because there may be all sorts of viruses and bacteria on the mask itself. If you touch the mask with your hands, you contaminate your hands. If you then touch your face, you may infect yourself from the mask.
Mask should always be put on using the ear loops or ties, never by touching the mask itself. Furthermore, you should never drag the mask below your chin or above your head, because you may also contaminate the inside of the mask that way.
Do masks ordered on amazon needs to be sanitized? How to sanitize?
Most masks are not designed to be disinfected. Trying to clean and disinfect masks may compromise the integrity of the mask and place the wearer at increased risk. Masks received in sealed packages from reputable manufacturers should be considered safe to wear.
Can face masks be sanitized and reused?
Sanitizing and reusing masks may make you sick, so you must be very careful!
Mask manufacturers advise against sterilizing and reusing masks. However, the reality of our crisis forces us to take measures to protect the safety of ourselves, our families, and our communities. Sterilizing masks is an area of active research, and there are no definitive conclusions yet. That being said, the most important way we can preserve the integrity and sterility of our masks is to use them appropriately when we put them on, wear them, and take them off. The critical point is to never touch the mask nor let it contact any surfaces beyond the nose and mouth.
The reason is that when people touch the mask with their dirty hands, they contaminate the mask, which may lead to self-inoculation when they take the mask off at a later time (if virus on their mask contaminates their hands and their hands then touch their face).
Theoretically, when they exhale, they may also blow the contaminants into the air around them, placing others at risk. Furthermore, when people pull masks below their chin or above their head they drag whatever contaminants are on their face on their mask, which will then come in contact with the mucosal membranes of their nose and mouth later (the primary entry point of the virus to infect us). This represents yet another mode of self-inoculation.
Lastly, when putting the mask on or taking it off, it is critical to follow the directions specific to that mask type and not touch the portion of the mask that comes in contact with your face. Otherwise you have that same risk of self-inoculation, potentially doing more harm than good.
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The information provided in this post in intended for general education. It is not medical advice. While I make every effort to provide the most up-to-date information, please note that new data is continuously becoming available and may change the conclusions I present here.