Dubai: It’s been nearly 10 months since the first COVID-19 case was reported from Wuhan China. Ever since, wearing a face mask has been accepted as the ‘new normal’.
In the absence of a well tried out vaccine for the masses, doctors say, the mask is the new vaccine, social distancing or keeping two metres away from another individual when outdoors, the new way of maintaining immunity and hand wash as well as sanitisers the new medicine against COVID-19. Together, the combination of these three precautions can go a long way in preventing the community transmission of COVID-19.
Why wearing a mask is important?
Giving a traditional perspective, Dr Wael Al Amin, head of infection control at the King’s College Hospital, Dubai, told Gulf News: “from times immemorial, the people in the desert always covered their faces with a fine cloth. Be it the Tuaregs or the Bedouins and other resilient nomadic tribes in the desert, they always wrapped one edge of their turbans over their faces to prevent fine particles of sand from entering their respiratory tract and lungs which are the most vulnerable. So we have known that this practice of using a barrier to cover our respiratory tracts prevent fine droplets of sand from getting into our lungs. Extending this practice to the modern times, we now know that the face mask, when worn properly, covering both our nose and face can stop the droplets of COVID-19 infection trapped with moisture that are suspended in the air from entering our respiratory tracts and infecting members of the community.”
How does COVID-19 spread through the air?
When people, talk, cough, laugh or sneeze, they tend to spew saliva, especially in words that contain the phonetic ‘ph’, ‘th’ sounds. This action creates an aerosol affect. Aerosol affect refers to the saliva and mucus from a person’s mouth and nose getting trapped in with moisture in the air and the dust that remains suspended in air. The heavier droplets fall to the ground, but droplets that are around 5 microns, where the moisture evaporates quickly tend to linger in the air causing the virus to travel.
This aerosol affect makes the virus airborne for some time and people without masks can catch the infection through these respiratory droplets.
In a research conducted by doctors and published in the New England Medical Journal, scientists conducted experiments that proved that SARS COV2 virus could linger in aerosols of less than 5 microns in size.
How speaking, sneezing or talking can cause COVID-19?
In this experiment the doctors attempted with use of a fluorescent light to mark the pathway of the saliva droplets when a person spoke and it was seen that when two people held a conversation the air between them lighted up with saliva droplets. The doctors concluded that a traditional droplet that can spread the virus is around 5 microns in size. Therefore doctors reiterate the correct use of masks and explain how masks actually stop the infection.
Dr Mohammad Al Azzawai, Head of the Emergency Department at the Mediclinic, Welcare Hospital and member of the hospital’s COVID Taskforce, explained: “The face mask in combination with social distancing and handwashing is the most effect method of stopping the spread of COVID-19. People must realise that they wear the mask to protect the other person around them while others too must realise this. This is a reciprocal action and mutually helping each other can help us prevent community transmission.”
Dr Al Amin said: “The spit spray from a person is a subject of research for many aerodynamic studies and there are many variables to it such as distance, volume of spit, wind speed etc. For the common man it should suffice to say a distance of two metres from another person will help avoid getting affected by the spit spray.”
The two health practitioners cleared several doubts about how masks worked in effectively preventing spread and infection and why it was the most important tool in our battle against COVID-19.
How do the masks work?
• While health care workers wear the full Personal Protection that includes the tightfitting N-95 masks around their face and noses, members of the public are advised to wear either the normal 3-ply mask available at all pharmacies or home- made washable cloth masks. The 3-ply mask has three protective barriers with the outer barrier being fluid resistant. So if a person is positive, wearing a mask will prevent droplets of saliva from escaping into the atmosphere. Both the barrier and the distance play an important part in stopping community transmission.
• In case of members of the public who are not infected but wear the mask, their mask will provide a double barrier in presence of a positive person. Even if the droplet of saliva from an infected person were to escape from the crevices, if the other individual is maintaining social distance and wearing a mask, he or she will be able to effectively stop the droplet from entering his or her respiratory tract.
• People in confined spaces like in open-plan work spaces must wear masks at all times. Dr Al Amin explained: “It is important that people working in open plans or office spaces keep their masks on at all times as scientists speak of the viral load and higher infectious doses of the virus in confined spaces with poor ventilation and no outward vents to get fresh air in. This can result in the infectious particles lingering in the air for a longer time. Wearing the mask at all times, reduces the burden of infection of the droplets and combined with two metre distance, this works very effectively in stopping spread of infection.”
• Masks must be changed as soon as they get damp with mouth contact or changed every four hours to avoid any chances of contamination. Masks must not be reused for the same purpose.
• Avoid touching your face and outer surface of the mask. It is an evolutionary fact that human beings tend to touch their faces at least 16 times in an hour. If one touches the outer surface of a mask and then ones face, it is easy to infect yourself in case one has been in touch with a COVID-19 patient. The eyes and nose become the conduit for the virus to travel to the respiratory tract. Therefore hand washing and sanitisation plays an important part in infection control.
• When going to eat food in a workplace, it was important to take off the mask carefully without touching the face, washing hands and placing the mask in a zip-lock bag to avoid any external contamination if one was to reuse after the meal.
• Disposal of masks have to be done away with in a proper way too. Individuals are advised to take off the mask and place it in a covered paper bag, seal it and dispose. Discarding masks on road carries heavy penalties and if you must dispose in a public garbage bin, take care to place it in a covered paper bag to avoid infection spread advised the doctors. Hospitals use hazardous bins to discard all Personal Protective Equipment (PPE) including face masks which are then incinerated.
Different Masks and their effectiveness
N95: These masks as the name suggests is a non- oil resistant respiratory protective device made of non-porous polypropylene material which is recommended to be worn by health officials in the frontline of COVID-19 as an integral part of the PPE they have to wear. These are also called respirator masks and it has a very tight fit around the face, in many cases has a layer of charcoal lining to absorb any other pollutants and is effective in keeping out 95 per cent of virus, bacteria, dust, pollen, smoke and other pollutants as small as 0.3 micron. It is meant for single use only and needs to be discarded safely by the health care worker after use in a closed hazardous waste dustbin. It keeps any chance of infection away from the wearer and is recommended for people who are exposed to a high level of infectious microbes and contaminants.
Surgical face masks: A surgical mask is a loose-fitting PPE with space on either side of the edges of the mask. It covers the nose and face of the wearer and is usually worn by surgeons and clinical nurses as well as dentists during surgeries. These masks can be worn by members of the public while visiting stepping outside from home. It is especially recommended for people who might be asymptomatic as this mask is recommended to be worn by those who might have infection. They are also meant for single use. These are not respirator masks as there is space on the edges and this can only prevent the wearer from spreading infection in case he is positive, but is unlike the respirator masks which has to be mandatorily worn by health care workers to keep out infection.
The FFI, FFP2 face masks: Many of these categories of ready-made layered polypropylene masks available in the pharmacies come with European FDA approval and they filter out all particles of germs, viruses, dust and pollen. Those available filter out up to 90 per cent contaminants.
In addition all home-made masks, made of sponge, fabric, latex or any other non- porous material come in the category of FFPI and FF2 devices.
FFP 3: These made up of special medical grade fabric coated with adsorbed activated charcoal. DuPont makes these with a special material called Tyvek which is a medical plus building material and with many layers of non porous material to filter out contaminants.
