Wearing two-layer masks is better for epidemic prevention ?
The US Centers For Disease Control and Prevention believes that masks must fit the face in order to exert maximum protection. They provide 8 ways to wear masks correctly for the best virus prevention.
The Delta variant virus has invaded the world. The latest anti-epidemic practice in the United States: "wear two layers of masks."
How to wear a mask more correctly? Why do I need to wear two layers of masks? Is it practically feasible? We have compiled Q&As from the US CDC report to clear your doubts.
Q: Is it dangerous to stay in the same space with strangers (such as going to a hypermarket or taking the public transportation)?
In a poorly ventilated room, the risk of infection is increased regardless of the distance.
According to a report by the US Centers for Disease Control and Prevention on May 7, the Corona Virus is mainly transmitted through three methods: droplets, aerosols, and indirect contact.
When people exhale, they will spray droplets of different sizes; the largest droplets will quickly diffuse into the air within a few seconds to a few minutes; when these droplets are dried, small droplets and aerosols will form, so small that they can stay in the air from several minutes to several hours. The risk of infection is highest when the distance from the infected person is 90 to 180 cm or 35 inches to 70 inches.
Therefore, many people think that keeping a safe distance can prevent infection; in fact, cases of infection still occurs from more than 180 cm away.
Examples include: the infected person exhales the virus indoors for more than 15 minutes or several hours, causing the virus concentration in the air to be high enough to spread to people 180 cm away; in some cases, when a person enters space that the infected person previously stayed and left may also become infected.
In the above situation, there are three other factors that increase the chance of infection:
・A closed space with poor ventilation or air conditioning can cause the exhaled water vapor to gather and accumulate in the space, especially small saliva or mist.
・Increase exhaled air, such as when the infected person exerts force or raises their voice, such as exercising, yelling or singing.
・Exposed to the above environment for more than 15 minutes.
As a rule of thumb, attending a BBQ party, going to the gym is a dangerous move.
Q: Wearing two layers of masks (one layer of cloth, one layer of surgical mask), is it really better to prevent the epidemic?
A: Correct. But it is difficult to do in hot climates and summers.
The US Centers for Disease Control and Prevention released a report on February 19, “Maximizing Fit for Cloth and Medical Procedure Masks to Improve Performance and Reduce SARS -CoV-2 Transmission and Exposure, 2021).
This report proposes two ways to wear a mask to ensure that the mask fits tightly on the face, which can increase the protective effect by 90% in practice (even 95% in the laboratory):
First, wear a cloth mask on top of a medical mask.
Secondly, after folding the medical mask in half, tie the ear straps close to the mask, stuff the excess fabric into the mouth cover, and flatten it on the face. (As shown on the following video)
The report also pointed out that the use of a mask fitter or a nylon cover similar to mountain-clumbing nylon jack on a mask, combined with other protective measures, such as keeping distance, avoiding crowds, avoiding poorly ventilated indoor environments, and washing hands frequently. This is te most effective way to reduce the spread of new Corona virus.
The US Centers for Disease Control and Preventiont of Disease Control and Prevention-How to Wear Masks-Corona Virus -Epidemic Prevention, Image source: U.S. Department of Disease Control
In April of this year, the US Centers for Disease Control and Preventiont released the technique of wearing masks again, emphasizing that masks must be fit and must be multi-layer masks (such as medical masks) that can block droplets in order to be most effective.
How to make the mask fit the face better ? There are six approaches:
The Six DOS to wear masks that better fit your face:
DO choose a mask with a wire on the bridge of the nose. Remember to bend the wire to make the mask close to the bridge of the nose.
DO use a mask fitter to prevent air from escaping from the edge of the mask
DO keep the mask close to the mouth, nose, and chin, and make sure that air does not flow out of the eyes or the side of the mask. If the mask is tight enough, you will feel warm air coming out of the front of the mask when you breathe, and you will also see the mask fluctuate with your breathing.
DO add another layer of protection outside the mask. If you wear a medical disposable mask first, and then wear a cloth mask with multiple layers of material, the cloth mask must be able to hold down the edge of the disposable mask.
DO knot the ear straps near the mask and stuff the excess part into the mouth cover.
Growing the beard may make it more difficult for the mask to fit the face shape. People with a beard can shave, trim their beard, or use a mask holder, or wear a medical mask first and then a cloth mask.
Two DONTs wrong ways to wear masks :
DO NOT wear two medical masks. Medical masks are not designed to fit the face tightly, and it is useless to wear two masks.
DO NOT wear another mask outside the N95 mask, just wear it alone.
In the hot summer time, wearing a mask when walking outdoors may be soaked with sweat. Once the mask is wet, its protective power is greatly reduced. ". Therefore, although the practice of "wearing two layers of masks" has a good intention, it may not work in summer time and can only be done indoors.
Learn more about the correct way to wear a mask: how to wear a mask? Download the U.S. Center for Disease Control and Prevention Guidelines
Q: Is spraying disinfectant water on the streets really just giving people peace of mind?
According to a report from the US CDC, the viability and infectivity of the virus will be greatly reduced by environmental factors such as temperature, humidity, and ultraviolet rays over time.
It is difficult for the virus to survive in places exposed to the sun outdoors, and it does not need to be disinfected. Although the virus will survive on the surface of the object for a period of time, it mainly refers to indoor door handles, elevator buttons, escalator handrails, etc. These are the places that need disinfection most.