COVID-19 Topic: Why is Mask-wearing Important and How are N95, Surgical & Cloth Masks Different?
The CDC has officially changed its COVID-19 guideline on mask-wearing and has advised all Americans to wear cloth mask/face-covering in public. Previously, the CDC has advised Americans against wearing any masks—neither medical-grade nor home-made—if they’re not sick or taking care of someone who is sick.
Why has the CDC changed its guideline? This article will explain why mask-wearing is essential not only for healthcare workers but also for the public, and answer your questions on the differences between N95 respirators, surgical masks, and cloth masks.
The biggest difference between N95 respirator masks, surgical masks, and cloth masks is that the first two are made with medical-grade fabric designed for filtration, whereas the third is not.
The Difference between N95, Surgical Mask, and Cloth Mask
The N95 respirator
- blocks 95% of very small (.3 micron) particles.
- forms a tight seal to the face and needs to be properly fitted to be effective
- Filters both large-particle droplets and non-oil aerosols
- is classified as respiratory protection but does not completely eliminate the chance of infection
Disposable surgical face masks
The FDA and CDC states that a surgical mask
- blocks large-particle droplets, splashes, sprays or splatters that contains virus or bacteria
- is loose-fitting and should be discarded after one use
- does not block small particle aerosols due to loose-fit and the quality of the fabric
- is less effective at filtering than N95 and does not eliminate the chance of infection
- is not considered respiratory protection
- are not made out of medical-grade fabric
- Anyone can make them with any available fabric
- Filtration abilities vary depending on the tightness of the fit and the materials used
How does each mask differ in their ability to protect you against the coronavirus?
Before we can understand how each mask protects you, we must first understand how the coronavirus spread.
The coronavirus is thought to mainly transmit directly from person to person. When an infected person coughs and sneezes, they emit virus-carrying respiratory droplets that enter another person’s body.
Respiratory droplets can also contaminate surfaces, where the coronavirus remains viable (able to infect) for hours or days. A person who has touched a contaminated surface and then touched their mouth, nose, or eyes can also become infected, though this is not thought to be the main way the coronavirus spreads.
Viruses do not only escape the body through big-particle droplets, but they also escape through small-particle aerosols. When a person talks or breathes, invisible large quantities of aerosol particles, typically 1 micron in diameter, are emitted into the air in the form of a “cloud”. A study has shown that by engaging in a 10-minute conversation in close proximity with another person, one can inhale around 6000 aerosol particles.
Researchers have artificially aerosolized the coronavirus into ambient air and found that they hang in the air and stay viable (able to infect) for up to three hours. However this experiment is done in a carefully set up artificial condition, and the coronavirus may not behave the same way out of the lab.
Scientists do not yet know how infectious aerosols are, or whether or not they play a main role in spreading the infections. More research needs to be done to fully understand the issue.
However, new data has shown that a significant portion of people who are infected by the coronavirus are asymptomatic (not showing any symptoms) or presymptomatic (has not yet shown symptoms). These people can infect others without showing symptoms such as coughing and sneezing, which means they might be spreading it via breathing and talking.
Therefore, even though scientists don’t know the extent to which aerosols are responsible for spreading the coronavirus, they suspect that they do play a role.
In light of new data from scientific studies pointing to the large number of asymptomatic spreaders, the CDC advises all Americans to wear cloth masks, especially in areas with a high rate of community-transmission.
Let’s review again how N95, surgical mask, and cloth mask can protect you against infection.
N95 protects you from both big droplets spread by sneezing and coughing and small aerosols spread by talking and breathing.
A surgical mask only protects you from droplets but not aerosols.
Cloth masks do not guarantee to block either droplets or aerosols. A study has shown cloth masks to be much less effective than surgical masks. You also can’t know for sure how effective your homemade mask is. In general, cloth masks with a tighter fit and a tighter fabric weave is more effective than looser ones.
If the cloth mask is so inferior, why is the CDC advising all Americans to wear cloth masks and not medical-grade masks?
One big reason is that America doesn’t have enough medical masks for front line healthcare workers, much less anyone else.
The US Surgeon General Jerome Adams tweeted back on February 29 “Seriously people- STOP BUYING MASKS! They are NOT effective in preventing the 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!”
Because of the shortage of supply, the government is asking people to conserve N95 and surgical masks for healthcare workers so that they wouldn’t get sick while working and can continue to take care of patients.
Even though cloth masks cannot effectively protect you from the coronavirus, they are still useful in combating the outbreak because wearing a cloth mask can protect the public from you.
Given the large number of people who have the coronavirus but show no symptoms, you can be one of them too. As a precaution, always wear a cloth mask or face covering when going out in public to avoid potentially infecting others. By combining mask-wearing and the social-distancing, the probability of asymptomatic transmission can go down.
The issue of not having enough medical-grade masks
Going back to the Surgeon General’s tweet, although many agree with Adams’ latter point that healthcare providers need personal protective equipment, the Surgeon General’s former point that masks are not effective in protecting the general public remains hotly contested.
Why are medical masks so important to the protection of healthcare workers but not the American public? There are several arguments made for why this is the case:
- People do not know how to properly wear a mask. They wear it wrong, exposing their nose. They touch the mask constantly, exposing themselves to more germs. They don’t know how to properly put on or take off a mask. With N95, the people don’t know how to get the respirator to properly fit, so it would be ineffective anyway.
- The risk of the general public being exposed to the coronavirus is low, especially when they’re social-distancing and washing hands. The risk to healthcare workers is very high and masks should be reserved for them.
The first point has been questioned by many opinion columnists, such as New York Times contributor Zeynep Tufekci, who says if improper usage is the only concern, the government’s course of action should be putting out educational material, just as they’ve put out information on how to properly wash one’s hands and practice social distance.
As to the second point, healthcare workers are at more risk than the general public, and they should be protected. But does that mean the risk of getting the coronavirus is low for the public, just because it’s lower than the healthcare workers?
Since February 29, when the US surgeon general tweeted for people to not buy masks, community-spread has increased. The US’s confirmed cases of coronavirus have skyrocketed, and experts suggest that the peak has yet to come. Outside of big cities like New York, even rural areas are also experiencing a surge in cases. The surge in numbers already didn’t account for those who don’t exhibit symptoms or don’t have access to tests.
Although the risk of infection is low for people who self-isolate, it may be higher for essential workers and cannot self-isolate. The risk may be especially high for essential workers who come into contact with lots of people and work in an enclosed space, such as cashiers.
For people with pre-existing conditions, even if their risk of infection is the same as everyone else’s, they fare much worse once they are infected.
Asian countries such as Taiwan, Singapore, and South Korea have practiced wide-spread mask-use from the very beginning of the outbreak, and they seem to have relative success at controlling the outbreak (though it is unclear how much of the success is due to mask-wearing).
The problem America faces is that there simply aren’t enough medical-grade masks to go around, so we cannot copy the other countries’ examples.
A new study from Lydia Bourouiba of MIT shows that when someone exhales, coughs and sneezes, they can emit a fast-moving gas cloud that carries both droplets and aerosols of various sizes to up to 27 feet away. The current CDC social distance guideline of “6-feet apart” is based on an outdated model developed in the 1930s which predicts that large particle droplets settle in close proximity.
The new study brings the serious implications that even 6-feet apart isn’t enough, since virus-carrying droplets, not merely aerosols, can reach another person 27-feet away. The study can also shed a new light on respiratory disease transmission.
If the coronavirus is able to travel much further than initially thought, then along with social-distancing, masks can be an essential way to protect both the wearer and the wearer’s community. Various masks can reduce the number of respiratory droplets the wearer emits and reduce the distance those respiratory droplets can travel to varying degrees. Various masks can also decrease the wearer’s exposure to other people’s respiratory droplets to varying degrees.
Although mask-wearing is very important, it is important to note that masks alone cannot protect you from the coronavirus. Social-distancing and frequent hand-washing should be practiced rigorously alongside mask-wearing to minimize your chance of becoming infected.
MOCACARE is currently selling 3-ply, fluid-resistant masks for those who need it. We encourage those with pre-existing conditions and those who work as essential employees to protect themselves.