Masks save lives. Make one & wear it.

Universal public mask-wearing helped “flatten the curve” in South Korea, Singapore, Hong Kong, and China. We can do it too–without taking clinical-grade masks from healthcare workers.

Leslie (Ziegler) Schrock
8 min readMar 31, 2020

You’ve likely seen the chart below showing the rate of coronavirus spread around the world. Perhaps you’ve noticed that East Asian countries–especially South Korea, Singapore, Hong Kong, and even China where this all began–have much flatter curves than Western countries.

Image credit: Financial Times

So what do these curve-flattening countries all have in common? Yes, their governments mandated system-level early testing, strictly enforced quarantine rules, contact testing, and tracing, social distancing and other hygiene recommendations like hand washing. But if you see photos from any of these countries you’ll notice something else: almost every single human out in public is wearing a mask.

Many humans in Hong Kong wearing masks.

Public mask-wearing has long been an accepted part of East Asian culture. One contributor: long-held shared philosophical beliefs tied to the importance of breath and deleterious health effects of exposure to bad “feng” (wind) in traditional Chinese Medicine. But public mask-wearing truly went mainstream as a result of the deadly 1918 flu pandemic and persisted through earthquakes, a second global flu epidemic in 1934, growing air pollution, SARS, MERS, avian flu, and many influenza seasons. Masks are so ubiquitous that chic versions have even made appearances on the catwalk.

When it comes to controlling COVID-19, Hong Kong’s public officials credited universal mask-wearing as one of the reasons a widespread outbreak did not occur. It was reported that everyone owned and wore masks and that 75% of people held over a month’s supply on hand. In Japan and South Korea, masks were distributed by the government for free and worn at all times. China reopened the country without reporting a resurgence of infections and guess what? Everyone still wears a mask there, too.

When asked what mistakes other countries are making in managing COVID-19, the director-general of the Chinese CDC (who did the first isolation of the virus that causes COVID-19, and co-authored two of the most widely read related papers in The Lancet and NEJM) called the absence of universal mask-wearing in the West an egregious oversight:

“The big mistake in the U.S. and Europe, in my opinion, is that people aren’t wearing masks. This virus is transmitted by droplets and close contact. Droplets play a very important role — you’ve got to wear a mask, because when you speak, there are always droplets coming out of your mouth. Many people have asymptomatic or presymptomatic infections. If they are wearing face masks, it can prevent droplets that carry the virus from escaping and infecting others.”
- George Gao, Director-General of the Chinese CDC

This breakdown of different country’s recommendations shows how little agreement there is on the effectiveness of mask-wearing right now, though as it appropriately calls out, there is “an essential distinction between absence of evidence and evidence of absence.” But in a break from the rest of the West, Austria jumped on the mask-wearing bandwagon and now requires a basic mask to be worn before entering the grocery store.

Wearing a mask is NOT a substitute for social distancing, good hygiene, and copious hand washing. It is a SUPPLEMENT to these very necessary measures.

Yikes. So why isn’t universal mask-wearing happening in the US?

Well, for one the United States Surgeon General stands by a recommendation from the WHO that while masks are necessary for healthcare and other frontline workers they are not for the general public and further, are too hard to fit to be wholly effective. And though it’s rumored the CDC is going to change their guidance, they also piled on and told the public to wear them only if they were sick–hard to determine with COVID-19 since so many people are asymptomatic and do not feel “sick”. Couple this with the very real, terrifying shortage of PPE (personal protective equipment) for healthcare workers and the fear that hoarding would make them even more scarce and the idea of visiting your local grocery store festooned in a mask seems less than desirable.

I have firsthand experience with that discomfort. Last week during my weekly trip to the grocery store, an older woman spotted me in my mask and walked over. Over a socially-distanced selection of citrus, she confessed that she put her mask on in the car and then took it off when she didn’t see anyone else walking into the store wearing one. Turns out, she was a nurse practitioner and after seeing mine, she committed to wearing hers on her next grocery store outing.

That is a major cultural distinction between East Asia and the US: Mask-wearing in the US signifies sickness or contagion, not prevention. But it wasn’t always that way. Rewind 100 years to that infamous 1918 influenza outbreak and wearing a mask was encouraged, even mandated.

100 years ago mask denialists were deemed “dangerous slackers”. Image credit: MyHeritage.

Why does mask-wearing matter when it comes to COVID-19?

This particular coronavirus (SARS-CoV-2) is highly contagious and is easily transmitted in droplets from coughing and sneezing. It has a 2–14 day incubation period and can also live for short periods on surfaces. People can be infectious before symptoms like fever, cough, or shortness of breath emerge, meaning a single asymptomatic human can spread the virus to many others without ever knowing it.

Let’s talk briefly about the math of disease transmission. R0 or “R naught” is how we define the epidemic potential, or how contagious an infectious disease is. Generally, if R0 is above 1, the disease will continue to spread. Under 1 and it usually stops. R0 doesn’t take into account “super-spreaders”, but instead gives the average number of people who will be infected from a single contagious person. For example, R0 4 means every existing case will create four new cases. Right now, R0 estimates for COVID-19 range from 1.4–3.5. If we can lower R0 simply by reducing the chance that an asymptomatic person will spread the virus by even 50%, the number of hospitalizations and mortality rates will go down exponentially.

To understand how these exponential rates really work, here is a cool epidemic modeling calculator.

If you want to dig into the mechanics of virus transmission and the specific biology of COVID-19, this excellent piece has you covered. TLDR: there is no question that surgical masks (or comparable cotton versions) cannot protect against tiny aerosol particles as effectively as an N95 mask. However, early research indicates that as opposed to other viruses that take hold in the lungs, nasal epithelial cells and the upper airway are the most receptive to SARS-CoV-2.

Sneezes can shoot large droplets that surgical masks or similar DIY models can filter up to 6m away. Combine this with the reality that the virus does not have to travel far into the respiratory tract to take root, and even imperfect protection seems worth pursuing.

And that is the point–public mask-wearing isn’t about perfection or only about protecting yourself.

It also shouldn’t be about the translation of interventions that work in clinical settings to the general public since we don’t even have enough gear for the brave people on the frontlines who need it.

Public mask-wearing is about decreasing transmission, especially from those that are asymptomatic, and reducing the already enormous burden on the healthcare system.

Masks also provide a useful physical reminder not to touch your face and are a much-needed open sign of solidarity that we are all in this together. #stayhome #socialdistancing #notouching

Ok, I’m convinced–how do I make a great mask?

A mask made at home is not up to the same clinical standard as an N95 or respirator, and DIY masks are not the right solution if you are a healthcare professional treating patients with COVID-19. For that reason, all clinical masks should be reserved for their use. Please please please do not hoard masks!

What are the design features that make a DIY mask effective?

Masks that have comparable protection to FDA-approved surgical masks form a seal that you can check by breathing in and out to see if it “puffs”. What makes that possible?

Nose clip
Ensures the mask fits over the nose and contours of the face across the cheekbones, allowing for little air leakage.

Lower tie
The top of the mask should be tied snugly toward the top of the head. The all-important bottom tie should be secured below the hairline around the neck.

Made with 100% cotton material
Clinical studies show that 100% cotton is comparable in effectiveness to some FDA-approved surgical masks.

What do I need to make a mask and how do I do it?

Good news to the crafty (and not so crafty): making your own mask can be as complicated or as easy as you want it to be. There are many designs out there: cool 3D printed models, those powered by vacuum bags, a scarf and two hair ties, a woman’s thong, and some people are just wearing scarves and bandanas, which is better than nothing.

If you’re looking for a design that closely simulates a surgical mask, my father-in-law, who happens to be a hospital epidemiologist with over 30 years of experience with infectious diseases including Ebola, HIV, SARS, and numerous others, is here for it. He designed a no-sew, washable mask that can be made with household items (a bedsheet, paper clip, and safety pins) and takes around 10 minutes to make. Watch below or visit for a step-by-step breakdown and cleaning tips.

Go forth, and wear your mask

My silver lining in these stressful weeks: watching people come together and feeling incredible pride in the frontline workers, from our incredible healthcare professionals to those working in grocery stores and pharmacies and the farmers growing the food to keep all of us fed. Wearing a mask helps keep all of them safe, too.

So don’t be a dangerous slacker–wear your mask proudly and do what you can to support each other. We are all in this together!

Looking for other ways to help?

Check out this list of worthy non-profits working on the frontlines to support those most affected by COVID-19.

If you want to donate medical supplies or give up your secret horde of masks, here are a few organizations to check out:
ProjectN95, Operation Masks, #GetMePPE



Leslie (Ziegler) Schrock

Author 📖 Bumpin’: The Modern Guide to Pregnancy (Simon & Schuster) 🕵️‍♀️ schemer