Face Coverings

Face masks have been worn in some parts of Asia for many years, but now many governments around the world are advising the use of them in public places as there are concerns that tiny droplets called aerosols can carry SARS COV-2. Many scientists around the world believe that this may be a transmission route of the virus as these aerosols can stay in the air for longer than bigger droplets that fall to the ground more quickly.

Along with other protective measures, such as social or physical distancing and proper hand hygiene, face masks may be an easy, inexpensive, and potentially effective way to stay safe and flatten the COVID-19 curve. 

Health agencies, including the Centres for Disease Control and Prevention (CDC) and the World Health Organisation now encourage all people to wear masks or face coverings when out in various public settings.

 

Why do face masks matter with this COVID-19?

The largest amount of viral shedding, or transmission, from SARS COV-2 happens early in the course of the disease. Therefore, people may be contagious before they even start to show symptoms. Also  scientific models suggest that up to 80 percent of transmission stems from asymptomatic carriers of the virus.  

 

As there are known incidences of the virus spreading in aerosols produced from choirs singing and from air conditioning carrying aerosols of the virus on currents to other parts of the restaurant (and also a bus) widespread mask use may help limit the transmission of the virus by people who don’t realise that they may have it. 

 

Types of face coverings:

Respirator masks

Fit- and seal-tested respirators are made of tangled fibres that are highly effective at filtering pathogens in the air. These respirators must meet the rigorous filtration standards set by the National Institute for Occupational Safety and Health (NIOSH).

 

The diameter of the coronavirus is estimated to be 125 nanometers (nm) and:

  • Certified N95 respirators can filter 95 percent of particles that are 100 to 300 nm in size.

  • N99 respirators have the ability to filter 99 percent of these particles. 

  • N100 respirators can filter 99.7 percent of these particles. 

 

Some of these respirators have valves that allow exhaled air to get out, making it easier for the user to breathe. However, the downside of this is that other people are susceptible to the particles and pathogens that are exhaled through these valves so these masks protect you but not other people.

Front line healthcare and other workers need to use these masks as part of their job 

Surgical masks

There are various types of surgical masks.These tend to be disposable, single-use masks and are composed of breathable synthetic fabric. 

 

Unlike respirators, surgical face masks don’t have to meet NIOSH filtration standards. They aren’t required to form an airtight seal against the area of your face that they cover. How well surgical masks filter pathogens varies widely, with reports ranging from 10 to 90 percent. 

 

Despite differences in fit and filtration capacity, a randomised trial found that surgical face masks and N95 respirators reduced participant risk of various respiratory illnesses in similar ways.

 

How these masks are used played a more pivotal role than the type of medical-grade mask or respirator worn by study participants. Other studies have since supported these findings.

Cloth masks

These can be made at home but are less effective at protecting the wearer because most have gaps near the nose, cheeks, and jaw where tiny droplets can be inhaled. Also, the fabric is often porous and can’t keep out tiny droplets.

However, experimental results suggest they are far better than no mask at all when worn and constructed properly.