*Covid-19 is new and it is a disease being spread currently throughout the world. Researchers and scientists are still finding out information about the disease. Therefore, some facts researched in this post can be modified or new findings could be added as the novel coronavirus spreads more throughout the world in this pandemic.
CDC now recommends the public to wear cloth fabric coverings to prevent the spread of the coronavirus. US president, Donald Trump also said at the briefing on April 4th that Americans can wear cloth masks when they go out in public. However, he mentioned wearing cloth masks is voluntary, not mandatory. The new guidelines still do not recommend the public to wear medical masks. WHO recommends that medical masks should only be worn by healthcare workers, caretakers and people who are sick with symptoms such as a fever or cough. CDC also says medical masks must continue to be reserved for healthcare workers and other medical first responders. Most people in Covid-19 affected asian countries wear masks. Some experts actually believe that it is why spreading of the coronavirus is less severe in Asia than Europe or North America. Some businesses in Asia even ban customers from entering their business without wearing masks. There are critical medical mask shortages and the public do not have access to them. Medical masks such as N95 or surgical masks are sold out everywhere. Even if they are available, they should be saved for healthcare workers. We won’t have hospitals, doctors, medical professionals, and emergency responders if they can’t be protected in the front lines of combatting the coronavirus. Then is a cloth face mask effective in filtering out the coronavirus? In this post, I share with you why wearing masks is important and how effective a cloth face mask is.
[Update April 15, 2020] Today, New York Governor, Andrew Cuomo issued an executive order requiring all New Yorkers to wear a mask or a face covering in public places in efforts to prevent the spread of the coronavirus. Last week, New Jersey governor, Phil Murphy said New Jersey residents must wear face masks inside stores. In Puerto Rico, Governor Wanda Vázquez also issued an order for businesses to prohibit entry to anyone not wearing some kind of face covering. California, Maryland ,Texas and Pennsylvania, Connecticut have also issued a same order of wearing masks.
Why Wearing Masks Are Recommended?
You can wear masks for two reasons. One is to protect yourself from the coronavirus and the other one is to protect others from droplets produced by you. Respiratory infections can be spread via droplets produced when a person coughs or sneezes. However, some scientists say just talking or breathing may spread Covid-19. Dr. Harvey Fineberg, chairman of the National Academy of Sciences Standing Committee on Emerging Infectious Diseases and 21st Century Health Threats told the White House on April 1st, “While the current [coronavirus] specific research is limited, the results of available studies are consistent with aerosolization of the virus from normal breathing… [coronavirus] could be spread by conversation, in addition to sneeze/cough-induced droplets. Current available research supports the possibility that [coronavirus] could be spread via bioaerosols generated directly by patients’ exhalation.”
According to a study by researchers at the University of Nebraska Medical Center (not peer-reviewed yet), they found SARS-Cov-2 particles in the both air and surface samples taken in isolation rooms where COVID-19 patients had been staying. In another pre-print study, the airborne SARS-CoV-2 was found in ICU and air samples in a Fangcang patient toilet at the Wuchang Fangcang Field Hospital. Airborne SARS-CoV-2 concentration increased with accumulating crowd flows. The study concluded that gathering of crowds with asymptomatic carriers is a potential source of airborne SARS-CoV-2. They also concluded that room ventilation, open spaces, proper use and disinfection of toilets can effectively limit aerosol transmission of SARS-CoV-2.
A 2019 study in the Nature Scientific Reports stated that the rate of particle emissions during normal human speech increases with the loudness of vocalization, ranging from approximately 1 to 50 aerosol particles per second regardless of the language spoken (English, Spanish, Mandarin, or Arabic). The louder you speak, the more aerosol particles were produced. The journal in Aerosol Science And Technology states that a ten-minute conversation with an infected, asymptomatic superemitter talking in a normal volume can generate about 6,000 aerosol particles that could potentially be inhaled by the susceptible person in close proximity. Also, another study published in The New England Journal of Medicine on March 17, 2020 found that SARS-CoV-2 can float in aerosol droplets for up to 3 hours. However, these studies have not examined how high a concentration of viable SARS-CoV-2 is needed to infect a person, and how these particles move through the air to susceptible people.
Although we need more information, there is a possibility that SARS-CoV-2 is spread via aerosols. When there was an outbreak at Christian group Shincheonji Church in South Korea, the director of the South Korean Centre for Disease Control, Jung Eun-kyeong, suggested at a press briefing that, “There is a possibility that the characteristics of many people sitting close together in a very confined space and holding service for more than an hour would have led to a few who were exposed infecting many other infectees. There may be practices within a church – like weeping or the belting of songs – that would encourage droplet transmission.” Also, 45 out of 60 Skagit Valley Chorale who attended a choir practice held in Washington State on March 10 have tested positive. No one at the practice had symptoms and they avoided direct physical contact. Health officials have concluded that the virus was almost certainly transmitted through the air from one or more people without symptoms. Virus-containing droplets could have spread into the air they breathed while the infected person or people were singing.
A new study by MIT researchers finds that droplets can travel as far as 27 feet when someone sneezes or coughs. Lead researcher Lydia Bourouiba, of MIT’s Fluid Dynamics and Disease Transmission Laboratory wrote in the study that the largest droplets rapidly settle within 1/8 about 3 to 6 feet 3/8 away from the person and the smaller and evaporating droplets get trapped in the puff cloud and can travel the room up to 1/819 to 26 feet 3/8 away. Although we would need more answers such as how much viral virus trapped in that puff cloud is capable of infecting another person, I don’t think I would want to be standing within that range. A barrier that can block or lessen droplets when a person sneezes or coughs may help.
CDC now advises the use of simple cloth face coverings to slow the spread of the virus. They said that a significant portion of individuals with the coronavirus lack symptoms and that even those who eventually develop symptoms can transmit the virus to others before showing symptoms. They said that the virus can spread between people interacting in close proximity including speaking, sneezing or coughing even if they don’t show any symptoms. Centers for Disease Control Director Dr. Robert Redfield said that a significant number of individuals that are infected – as many as 25 percent – actually remain asymptomatic. Wearing a mask may help asymptomatic individuals from spreading the virus unknowingly.
What Type Of Face Masks Are Available?
Then what type of face masks are available? How much protection do they provide? Face masks can be divided into two categories: Medical masks and non-medical masks. Let’s take a look.
Medical masks are used in healthcare settings such as hospitals. According to the US Food And Drug Administration, N95 respirators and surgical masks are personal protective equipment that are used to protect the wearer from airborne particles and from liquid contaminating the face.
N95 respirators can filter out at least 95% of very small (300 nm = 0.3 micron) particles. They can filter out all types of particles, including bacteria and viruses can be filtered out according to the CDC. They are designed to fit the face so that they reduce the wear’s exposure to airborne particles. However, they must be fit tested. All of air is directed through the filter media. If you wear a N95 respirator properly, minimal leakage occurs around the edges of the respirator when the user inhales. Only N95 respirators can prevent airborne transmission. According to 3M, China KN95, AS/NZ P2, Korea 1st Class, and Japan DS FFRs are “equivalent” to US NIOSH N95 and European FFP2 respirators.
Currently, there are critical shortages of medical masks such as N95 respirators, KF94, KN95, FFP2 and surgical masks. Therefore, the CDC does not recommend medical masks for the general public. The CDC recommends public to use simple cloth face coverings when in a public setting to slow the spread of the virus. Healthcare workers and emergency responders have to work with infected patients in close proximity, in a very confined space. Therefore, it is critical that they are protected.
A surgical mask, also called a face mask is usually worn by healthcare professionals in healthcare settings. Surgical masks provide limited protection from droplets and aerosols. They do not fit as tight as N95 respirators and do not filter out airborne bacteria or virus particles as much. According to the Food and Drug Administration, if worn properly, a surgical mask can help block large-particle droplets, splashes, sprays, or splatter that may contain viruses and bacteria reaching your mouth and nose. Droplets are larger respiratory particles that are 5 to 10 micrometers in size. They could also help stop people from spreading the virus. However, they don’t provide protection from airborne bacterias or viruses. One study concluded surgical masks provide very low protection against aerosolized infectious agents in the size range of 10 to 80 nm (0.1 to 0.8 microns). Also, surgical masks don’t offer complete seal around your nose and mouth. Therefore, the wearer can be exposed to the virus when he/she inhales. Surgical masks are designed to protect others from your droplets and aerosols when you cough or sneeze. However, they offer some protection from droplets, less than N95 respirators but more than cloth face masks.
Non Medical Masks
Non medical masks are cloth face covers.
Cloth masks can be made from fabric such as cotton, organic cotton or cotton blends. There are cotton masks available at variety of stores. Many people also simply make them using T-shirts, fabric or scarves at home. There are tons of DIY masks available online. However, cloth masks cannot prevent an airborne transmission like N95 respirators can as mentioned earlier above.
Is Wearing Cloth Masks Effective In Filtering Out The Coronavirus?
So if there are critical mask shortages with healthcare and medical masks should be reserved for healthcare workers and emergency responders, the public is left with non medical masks. Are they effective in protecting you from the coronavirus or spreading it? Let’s take a look.
In a 2015 clinical trial on the effectiveness of cloth masks, the rates of infection were consistently lower for surgical masks than cloth masks. However, some protection may be better than no protection at all. According to Benjamin Cowling, head of epidemiology at Hong Kong University and one of the authors of a groundbreaking recent study published in the journal Nature, which concluded that “surgical face masks could prevent transmission of the human coronaviruses and influenza viruses from symptomatic individuals,” said the concept of face covering is that something is better than nothing. Singapore is giving reusable cloth masks to every household so that public can still wear masks but at the same time they can save surgical masks for health workers.
A study by scientists at Cambridge University tested several household materials for the capacity to block bacterial and viral aerosols. Wearing a homemade mask, a surgical mask, or no mask was compared. According to the study, both masks significantly reduced the number of microorganisms expelled by volunteers. However, the surgical mask was 3 times more effective in blocking transmission than the homemade mask. They concluded that surgical masks are better, a homemade mask should be last resort. However, homemade masks would be better than no protection.
They also tested which household materials worked the best against the size of a typical respiratory droplet. Surgical masks had the highest filtration efficacy, then a vacuum-cleaner bag, then a dish towel, then a cotton-blend fabric. T-shirts and pillowcases had lower filtration efficacy. However, they suggested that T-shirts and pillowcases seemed to be the most suitable household materials for an improvised face mask. The reason is vacuum-cleaner bags and tea towels had lower fit score due to the thickness and stiffness of the materials. The study said that the slightly stretchy quality of the t-shirt made it the more preferable choice for a face mask since it will probably provide a better fit. The study said that the fit factor and comfort is also a very important factor to consider for a face mask on top of filtration efficacy. Even if the material of a mask has good filtering ability, if the mask doesn’t fit well around the nose and mouth, it won’t block out infectious aerosols coming from outside of the mask. Also, if the mask is uncomfortable so the wearer can not keep it on or can not breathe with it, then it is not practical. This study shows that any masks including homemade masks offer some protection and they are better than not using any mask.
Also a study in professional and home-made face masks reducing exposure to respiratory infections among the general population concluded that any type of general mask use is likely to decrease viral exposure and infection risks on a population level, in spite of an imperfect fit and imperfect adherence.
Can You Disinfect Masks And Re-Use Them?
Disposable masks are not intended to be used more than once. Centers for Disease Control and Prevention says disposable filtering facepiece respirators (FFRs) are not approved for routine decontamination and reuse as a standard of care. However, during a pandemic, when there are critical shortages of N95 respirators, extended uses and limited reuse can be considered. CDC offers Recommended Guidance for Extended Use and Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings. However, there could be chances of decreased protection caused by a loss of respirator functionality. CDC said preliminary data suggests limiting the number of reuses to no more than five uses per device to ensure an adequate safety margin. They said that potential N95 respirator surface contamination should be limited by using of barriers to prevent droplet spray contamination, for example. There are also situations that N95 mask should be disposed right away recommended by CDC. There are several methods of potential viral inactivation for N95 masks. Decontamination is not something you can do easily at home but requires industrial methods of disinfection such as Hydrogen Peroxide Vapor (HPV), Microwave Generated Steam (MGS), Warm Moist Heat (WMH), UVGI. According to a study published in the journal Annals of Occupational Hygiene, sterilizing methods such as soaking the mask in 75% ethyl alcohol, then let it dry, microwaving the mask, or cleaning the mask with bleach were ineffective. If you use alcohol, household disinfectant or bleach to disinfect masks, you can also inhale toxic chemicals.
Surgical masks are not intended to be used more than once. They can not be washed. There are no studies of reuse of surgical masks after disinfecting them. They should never be reused, disinfected or washed since the filter may not have the same efficacy or functionality.
Cloth masks can be reused after laundering. The CDC recommends laundering homemade face masks regularly. According to Don Schaffner, Ph.D., a microbiologist and distinguished professor at Rutgers University in New Brunswick, N.J, the washing and drying process should kill the coronavirus. Combination of hot water, detergents, long process of washing, rinsing, drying process should be enough for inactivating all types of the viruses.
If you are interested in organic hand sanitizers, please read my post, ‘Organic Hand Sanitizer – Effective Hand Sanitizer Without Harmful Chemicals‘.
If you are interested in non toxic cookware, please read my previous post, ‘Non Toxic Cookware Guide – What Is The Healthiest And Safest Cookware?‘
If you want to find out which bottled water brands are safe, please read my post ‘Safe Bottled Water Guide: Which Bottled Water Brands Are Safe?‘
If you are interested in non toxic dinnerware, please read my post, ‘Non Toxic Dinnerware – Which Dinnerware Is Lead-Free?‘