Demystifying the myths about nose mask; mechanism and principle of filtration
This happens to be the concluding part of the article I initially published some few month ago regarding corovirus. You can read it HERE- Critical and detailed insights on Covid-19: All you need to know. Ought to have finished this article long ago but due to busy schedules, it was not so feasible. Better late than never.
This article is intended to enlighten the reader on the principle of filtration involving nose mask, uncovering the main facts about different types of PPE (Personal protective equipment), how to identify original nose mask, basic qualities a standard nose mask must have, the proper way a nose mask must be worn against the falsely spread methods of usage, why N95 and N100 are much better protective than surgical mask, health implications of nose mask overusage and more.
This is going to be an interesting read, there are some things you probably must have been doing out of Ignorance, reading this article will enlighten you. Endure to take a chill glass of soft drink because it is gonna be a long ride but I can assure you that it is worth your time. Let's get on with this shall we.
Since the outbreak of corona virus, there have been great concern and increased usage of surgical mask. The price of this medical personal protective equipment (PPE) speedily sky rocketed. Retailers suddenly began to hoard and as well as increased the price of this equipment due to the fact that importation became a major challenge.
They were obviously scared of going out of stock. Due to fear of the unknown. They probably believed that they might not be able to get new delivery when their old stock is finished and there is every likelihood of an increase in the price of importation of new stock.
Corona virus pandemic have caused not only an increase in PPE prices, but have also caused increase in some medical and general commodities like hand sanitizers, testing diagnostics kits, non contact thermometers and more. Getting them now is more like getting the Japanese passport.
Bearing in mind that China is one of the major supplier of commodities to Africa, with emphasis on Nigeria and other neighbouring African countries. Getting some of this equipment is now is major problem to the common man.
The rich and well placed individuals use more and better PPE (ventilators) than health care providers who are are actually supposed to be using them.
The politicians and well to do individuals are able to get the more advanced respiratory masks such as N95 and N100 while the ordinary health care provider use the less effective surgical mask.
Prices of virtually anything that will reduce the spread of the disease went up. Due to the several travel and trade restrictions, many outlets took advantage of the pandemic to exploit the common man.
Well looking at the scenario, one wouldn't want to fully apportion the blame on them as they are also fighting to stay in business. Getting new stock would obviously be difficult as the producers would as well take advantage of the present situation to increase the cost price in a bid to make more profit since there is high demand. This is simple economics of demand and supply.
Due to the outrageous increase in prices of sanitizers, personal protective equipments such as nose masks etc, this has forced people into improvising by producing their own hand sanitizers and also the trending stylish design of nose mask made from fabrics. This is also recommended by regulatory bodies.
You could actually make your own nose mask by following the procedure in this document by CDC: how to make nose mask with clothes
To ensure you are on the safe side, do not buy any hand sanitizer whose alcohol concentration is less than 60%. Preferably, for nose mask made locally, avoid buying from those hawking them on the road. Some persons test and return the nose masks to the sellers just in a bit to look for the one that perfectly suit them and this is a very dangerous practice.
The person testing this nose mask could be infected. It is much better to get from your tailor or fashion designer. Currently what people do now, remnants of your material can be used to sew nose masks for you. All you need do is to instruct your tailor to get you enough nose mask from the remnants of your clothes.
Primarily, the use of the surgical mask is by health care professionals during surgery and when providing or carrying out some medical procedures. It is usually worn by these healthcare professional to prevent any droppings from their mouth from contaminating surgical wounds thus protecting the patient.
It was designed to prevent infectious agents which can be virus, fungi, bacteria and other pathogens (micro rganisms with ability of causing diseases) from infecting the wearer. Surgical mask were never designed to be used for a very long time, it has health implications.
Due to increased concern about infectious diseases most especially those that are transmitted through respiratory droppings, the usage of this PPE has shifted from medical personnels to non medical personnels, all in a bit to prevent the wearer from diseases. There need to be a shift usage of surgical mask back to health workers and professionals.
Using surgical mask is not a problem but the main concern is how much do you know about this PPE and its correct usage. Most times I see some persons with a very dirty and worn out face mask. Some are even ignorant of how this PPE is correctly used.
What if I tell you that the nose mask, be it the one made locally or foreign made can as well be a source of infection to you if not properly used or handled. There are very important steps and procedures for the usage and disposal of the nose mask you need to know and remember always.
The face mask is one of the basic personal protective equipment that can prevent the wearer from infectious agents and as well prevent the wearer from infecting other persons. Read the last statement again and think deeply; it protects you and as well as prevents you from infecting others.
What this statement means is that the nose mask has dual function when making reference to protection. So how then do we wear it? First you need to understand the various parts and components of the nose masks. Knowing this, gives you a proper understanding of its usage.
We will begin with the describing this parts and their functions before delving into the proper usage of the nose mask.
It is very important I let you know that, the surgical mask is not the same as N respirators - a device designed to prevent the wearer from inhaling airborne diseases and viruses. The major striking difference between surgical mask and respirators is that, respirators offer higher air resistance than surgical mask and this consequently means higher protection.
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The surgical mask is mainly designed to prevent the wearer from being splashed with liquid that come from respiratory droppings or through the nasopharynx as they could contains viruses and bacteria from infected person and it also prevents the wearer from transmitting respiratory bodily fluids or secretions to others when they cough or sneeze.
Though the surgical mask are less effective when compared to respirators because the respirators are far more protective when it concerns patients with severe cases of infectious viral diseases. You hardly see a health professionals wearing surgical mask when attending to patients with Corona virus, rather they wear respirators.
Due to the increased air resistance, there could be a tendency of build up of air pressure hence this is why some respirators e.g the N-95 come with exhalation valve which helps and makes breathing easier for the wearer and also helps to reduce the condensation build-up inside the mask.
Under normal circumstances, face mask worn by the healthcare provider ensures that the healthcare provider does not contaminate an open wound with salivary secretions from the mouth while talking. It also keeps the hands and fingers from contaminating the nose and mouth.
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The shift from only usage by healthcare professional to the general public occurs majorly due to infectious disease outbreak, Just like we have a seen in the case of the current pandemic Corona virus outbreak.
Depending on the type you buy, generally, almost all surgical mask and respirators have ties, ear loops or bands. It also has a stiff bendable edge which helps you determine which area is the top and bottom. Once you get a surgical mask, the stiff bendable edge is the top and it is this area that is meant to be molded to the shape of the nose.
Before you use a face mask, you must be able to determine which area is the front and which is the back. Usually, the front side of the face mask is the well coloured part and it expected to be facing out. The green/blue coloured part is meant to be facing out always.
When putting on the the face mask, You are expected to try as much as possible not to touch the inner white layer, doing this will result to contamination. Touch the stiff bendable area only when you are putting on the face mask when making an attempt to mold it into the shape of your nose.
Proper fitting of the edge on the nose is one factor that ensures you are well protected from infectious droplets. A nose mask you put on, must be able to offer some form of air resistance. If you put on a nose mask and there is no form of reduction in air flow or the way you breathe then it actually does not offer much protection. For more details and illustration visist Centre for health protection, department of Health, Hong Kong special administrative region
When removing the face mask, you must not for any reason touch the front side (the well coloured area). It is already contaminated. After removing a nose mask ensure to wash your hands in running water with soap or detergent.
For the N respirators, one of the major factor to be considered when putting them on is to ensure that it is perfectly fit around the region of the nose and mouth. Just like the surgical mask, respirators even offer much more air resistance hence better protection. They have tight fittings around the mouth and the nose and this also mskes them more superior than the surgical mask.
In summary, the higher the air resistance, the greater the protection masks offer.
Mechanism of filtration in standard surgical mask and respirators is quite complex but I will make it as simple as it can be as usual. The type of filters in most modern surgical mask and N-respirators are fibrous in nature. They collet particles through three mechanical ways namely:
•Inertial impaction
•Interception and
•Diffusion
These three mechanical mechanisms work to ensure that particles are captured appropriately. The inertial impaction and interception both work together to primarily capture larger particles while diffusion is responsible for capturing of smaller particles. Some times, the filters could be made of charged fibers thus making them to operate based on electrostatic attraction (with particles of opposite charges getting attracted to the mask)
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With the electrostatic charges in action, it makes it easier for it to capture both larger and smaller particles. At any point any particle that is oppositely charges passes, they are immediately trapped.
During the stage of inertial impaction, those particles that have high inertial due to their size or mass cannot move along with airstream thus, they are automatically diverted to the filter.
Similar thing happens during interception, larger particles are intercepted when they jam or get closer to the filter fiber but during diffusion, what happens is that, because smaller particles have lesser weights, they are easily bombarded by air wave thus causes them to deviate and come in contact with the filter where they are consequently trapped by strong molecular forces thus, making it very difficult for them to be released.
Over some months now, there has been a serious misconception on the proper use of the nose masks. It is even quite unfortunate that even some of our very own health workers are guilty of this. The misconception is this:
"If one infected with a disease, you are expected to wear the face mask in such a way that the front side (coloured part) faces outside while the white part faces you. On the other hand if you are apparently healthy, you put it on with the coloured part facing inward while the white part facing outward."
From all indications and findings so far, no regulatory body backs up such claims, WHO and CDC, NCDC and other health regulatory body have never made any public notice or statement to support such practice. This is the problem you get when some fakes news keeps spreading without governmental agencies quick intervention to dispute and nullify false claims.
As it stands, there is only but one correct way to wear the surgical mask and that is:
"the coloured part facing outside while the white part facing inwards" it doesn't matter if you put it on to prevent being infected by other people or because you are infected and you don't want to infect others."
Let's take a look at the architecture of the surgical mask, you will understand better and why.
A good and standard surgical face mask has three layers. The outer, first or coloured layer is regarded as the fluid-repelling layer (hydrophobic). This layer primarily prevents any fluids from gaining access into the nose mask.
Next is the middle layer that basically serves as the barrier or hindrance to germs, it is more like the filter. It does the primary job of trapping germs, bacteria and viruses particles that might have escaped the first layer.
The innermost or last layer is the moisture-absorbing layer. The innermost layer absorbs fluids when we cough, sneeze or talk. It is able to absorb particles from the mouth of an infected person as ensures that they don't infect others.
Any surgical mask that doesn't have these three basic layers is substandard and cannot be used to protect against any infection like corona virus that is transmitted through respiratory droplets.
Now, how will you feel that you are talking and then all the particles coming out of your mouth is landing against the fluid repelling (coloured) layer instead of the moisture absorbing layer.
Your mouth and nose will be virtually be in contact with most of all the particles coming out of your mouth since the coloured is repelling fluids and does not absorb them.
Qualities that determines a standard mask in addition to the above
It does not matter what the goal is; to prevent outward or inward transport of dangerous particles, more emphasis is placed on the fact that the filter of the mask or respirator must be able to capture all range of dangerous particles usually within the range of (less than 1 to greater than 100micro meters) over a range of air flow (10 - 100L/min).
A quality face mask is determined by its pore size, efficiency and filtration rate. The pore size of the mask on its own determines the efficiency of the filtration rate of the mask. Another factor is the rate of air resistance by the face mask, a quality face mask is expected to have some degree of air resistance and pressure drop.
This quality ensures that bio-aerosol or respiratory droppings doesn't have easy and direct access through the pores of the face mask. Not every mask are suitable and effective in preventing various bio-aerosols especially some viruses that are very small in size. Generally, the pore diameter of most surgical mask ranges from 16 - 51 microns.
Any bio-aerosol less than 16 microns will definitely pass through the micro pores of the mask. Hence the need to know the suitable and quality mask for infectious diseases. Mask with lesser pore size are much more effective and they have higher filtration rate when compared with those with higher pore size. The quality of a mask should never be ignored. Always go for those masks with lesser pore size.
The inner layer or white side of the mask is designed to contain, absorb and filter droplets of microorganisms that are released from the mouth and nasopharynx of an infected person. So when infected or probably you sneeze and cough, you are expected to put on the face mask to prevent you from infecting or spreading the disease to others.
How effective are surgical mask?
Surgical mask are less effective in protection when compared to N95 respirators which are well designed and suited for to filter off infectious particles in a more stringent way. Healthcare providers are more in use of the N95 respirators because they offer better protection than the surgical masks since these people are much closer to the critically ill patients with Corona virus. It is important that you know this, surgical mask are not reusable and you are expected to discard it after usage.
Is the usage of mask enough to protect against Corona virus?
The answer is an emphatic no! The use of sanitizer and washing of hands with soap and running water goes a long way to ensure you do not get infected. Another's reason why you are advised to wear face mask is to reduce and minimize hand contact with your face, nose and mouth.
When you cough, ensure to use a disposable handkerchief or tissue paper. You can as well cough into a flexed elbow rather than coughing into your hands. Wash your hands under a running water and not inside a bowl of water.
Wrong practice by people when washing hands
It a common practice by people to use their hands to open a tap water and after still use the washed hands to close the tap, this is very wrong. Remember your hands were dirty when you opened the tap and obviously you must have deposited some germs or virus on the tap key.
The right thing to do is to call someone whose hands is clean to assist you in opening the tap. In the absence of anyone, what you do is to open the tap and wash both your hands and the tap lock very well before locking it.
Lastly, we will end by describing the health Implications of using nose mask wrongly and for a very long time.
Truth be told, the surgical masks or respirators are mainly for health professionals and not for general or public use. As a human, you are meant to breathe freely without any form of air resistance.
In a situation where you're unable to breathe freely for a very long time due to air resistance offered by the surgical nose mask definitely there will be increased accumulation of carbon dioxide which you are meant to breathe out and reduced intake of oxygen.
Increase accumulation of carbon dioxide ultimately increases the level of carbon dioxide in the body system leading to a condition known as respiratory acidosis where you have reduce pH (increase in acidity) of the blood.
Increased acidity of the blood definitely leads to complications that can be detrimental to the physiological state of the body. It is because of this that some respirators have exhaltation valve to ease breathing unlike surgical masks that does not have exhalation valves.
In surgical mask, you have to do more work in breathing to get more oxygen into the body system. This does not pose well for the healthiness of the body system. Bear in mind that putting on the nose mask mesns you inadvertently will be taking in or inhaling a fraction of the previously exhaled carbondioxide and as this continues, the more you keep struggling to take in more oxygen to compensate and remove the steadily increasing carbondioxide.
The use of mask for prolonged time also comes with pressure ulcers and pains. Any N-95 respirator that is tightened onto the face puts great pressure on the face skin through its edges and this leads to irritation to the area of the skin it is in contact.
It can be a serious problem for those that have chronic obstructive pulmonary disease (COPD) like emphysema - a lung condition that causes shortness of breath. They can even worsen breathlessness.
Decreased intake of oxygen can be detrimental to the health as it can lead to syncope or fainting, since the brain is not getting enough oxygenated blood. Bear in mind that the brain is the first centre of the body system to detect low oxygen, when oxygen level falls below standard you are likely to pass out.
You mustn't wear nose mask all the time. Put it on only wear when necessary and if needed. Don't wear nose mask in your house or in your car while the AC is turned on and glass wind up.
Keep your body system balanced by breathing in fresh air so that you don't accumulate carbon dioxide and consequently complicating matters for yourself in a bid to protect yourself against covid-19.
Stay safe, until next time❤️❤️❤️
References
¶How to put on the nose mask, coloreds side outward
¶put on a medical mask, question?
¶Double layer design of the nose masks
¶Center for diseases control- filtration mechanism of nose masks
¶Increased face masks wear can lead to skin irritation and damage
¶Emphysema
Very good very detailed article, that's how a friend is when something is necessary increases in price, that's why my uncle always tells me sells necessity