Friday, April 3 the CDC recommended:
“Everyone should wear a cloth face cover when they have to go out in public, for example to the grocery store or to pick up other necessities. Cloth face coverings should not be placed on young children under age 2, anyone who has trouble breathing, or is unconscious, incapacitated or otherwise unable to remove the mask without assistance.”
The CDC was clear that “the cloth face cover is meant to protect other people in case you are infected.” More on that below. The CDC also stated:
- Do NOT use a facemask meant for a healthcare worker
- Continue to keep about 6 feet between yourself and others. The cloth face cover is not a substitute for social distancing.
Dr. Jerome Adams, U.S. Surgeon General, gives a 46 second video about how to convert a simple winter scarf and two rubber bands into a face cover. Also check here for more Q/A on cloth face coverings by the CDC.
This might seem to be a reversal of Dr. Adams’ February 29, 2020 tweet in response to Americans panic-buying all the surgical and N95 masks (specialized microfiltration respirator masks):
“Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can’t get them to care for sick patients, it puts them and our communities at risk!”
It is not, and he was right on more than one point. If healthcare workers all get sick, there won’t be anyone left to care for the rest of the public. If health systems fail, the epidemic curve steeply and broadly increases, and that is bad.
He was also right that there was, and still is a big shortage of personal protective equipment (PPE) all over the country (and in many other nations). N95s are needed by medical personnel who perform procedures which might result in aerosolization of virus, such as intubation of people with COVID-19. N95s, or some other specific PPE are also worn by medical personnel in the presence of suspected and confirmed cases of COVID-19 generally, though I have heard from colleagues around the country who may be running out of those supplies. This places them at very high risk.
Paper surgical masks have a role also for medical personnel, and should not be worn by the general public. Take a moment to consider that when a surgeon and his or her team wear a mask, they are protecting the patient from their own respirations: respirations which contain droplets, droplets which might contain bacteria, viruses, or other pathogens.
Dr. Adams was also right that with an airborne virus a paper surgical mask is not effective in preventing the general public from catching the virus. This point is a complex thought contained in a tiny tweet. A paper mask (even if you are wearing it correctly, and many people are not), will not prevent aerosolized particles from being inhaled because they are so tiny. Even if you wear a face cover, stay away from sick people.
Being in the proximity of a sick, coughing and/or sneezing person is the most likely way to catch this virus, because you will probably be exposed to high numbers of active virus particles, which means a better chance of getting some of them into your respiratory system. It might also mean a more aggressive case of disease. In medicine a general principle is that being exposed to higher numbers of infectious particles is usually a bad thing, and might explain why otherwise healthy medical personnel made up about 15% of cases in China (and a high number of cases in the U.S.). It is common knowledge that droplets can travel much farther than 6 feet after a sneeze or a cough. A very recent report demonstrated droplets up to 27 feet after a sneeze. Click to see the video and read the report in JAMA.
The droplet range of 6 feet is meant for people who are not coughing or sneezing. However, even breathing or speaking usually causes people to expire respiratory droplets. And, louder talking requires more air, thus is likely to generate more droplets. So… loud talkers, you know who you are (or at least everyone else does), it only makes sense to tell you to lower your voice for public safety. And, go ahead and keep that in mind from now on.
The most important consideration with wearing a cloth face cover in public is that you might not know you are infected, and still be able to spread the virus. CDC authorities are reporting that asymptomatic carriers might make up about 25% of all infections. These are not people who qualify for testing under current federal or state guidelines. These are not people who are even aware they have been infected. Even among those who will become symptomatic, data shows they are shedding virus particles during the 48 hours prior to symptoms. For these reasons wearing a cloth face cover in public can limit the spread of the virus. When wearing a face cover, put it on properly over your nose and mouth. Do not lower it to speak, and do not touch it a lot. Only touch your mask with clean hands. But please don’t forget, even if you wear a face cover, you should still stay at least 6 feet back from even seemingly well people.
Finally, there are many free patterns available on the internet if you want to make your own mask. One a friend gave me looks nice. You have to make sure there are enough layers and the right kind of material is used. It might surprise you to find out you may already have what you need. In 2006 the CDC posted a page about how to make an 8-layer thick cloth mask out of a Haines cotton T-shirt.
If you want to make a very strong DIY mask, a Maine physician posted this video about how to make a mask that contains a pocket, into which you can insert a HEPA filter cut from a vacuum bag.
