If ever there is a symbol of the COVID-19 Pandemic it would be the (K)N95 Face Mask, a simple unglamorous device which not many people outside the pollution hot spots of the world had heard about. (K)N95 mask is a face mask designed not only to filter out at least 95% of all particles with a diameter greater than 0.3 micrometers but also to achieve a close facial fit. A surgical mask is designed to protect the patient from the droplets of the doctor! It wasn’t designed to protect the doctor from the patient. They are not effective in blocking particles less than 100 micrometers but more importantly they aren’t designed to have a close facial fit so air leaks through the gaps between the mask and the face.
An older, pre‑SARS‑CoV‑2 Chinese study in 2013 half found that twice as many health workers (17%), contracted a viral respiratory illness (like influenza or rhinovirus), when wearing a surgical mask while treating sick patients, compared with 7% of those who continuously used an N-95.
People often prefer to use a surgical face mask, it is “surgical” after all, isn’t it? The word “surgical” carries with it an aura of asepsis and clinical cleanliness but unfortunately it is misleading. The artificial debate around Surgical vs (K)N95 masks centers around the debate around the possible ways of transmission of the Coronavirus. The WHO and other national and international bodies insisted for a long time that transmission was solely through droplets, then when confronted with the evidence of increasing number of medical staff falling ill despite wearing surgical masks they revised their opinion to say that transmission could also be due to aerosols but that aerosols were produced only through medical procedures, hence only medical staff should wear (K)N95 masks and that in fact other people shouldn’t wear them so that more masks would be available for medical staff! It took an open letter from 239 scientists from 32 countries to make the WHO reconsider and recant (to a limited extent).
The WHO has clung to an outdated definition of airborne transmission and made an artificial distinction between droplets and aerosols. People produce both aerosols and droplets when they talk and sneeze, you don’t have to look beyond “Super spreader” events be convinced of that! Nature doesn’t distinguish between droplets and aerosols!
Scientists may have the luxury of not making recommendations till they have the evidence to back it up which is the principle of “Evidence Based Medicine” but real life situations demand that you make life and death decisions based on the information which you have. In the case of the Coronavirus, scientists have found themselves suddenly thrust into the spotlight being called upon to recommend measures which impact every aspect of the nation that they belong to. They have found themselves pulled in all directions by different and powerful factions with deep economic and political interests in the recommendations which they would make.
Droplet transmission means that less precautions need to be taken and the economy may be opened up with greater ease whereas aerosol transmission implies more stringent measures need to be taken to protect people’s lives and the economy needs to be opened up more gradually with more money spent on safeguarding citizen’s health.
Surgical Face Masks may make you feel good about yourself but don’t really protect you from the coronavirus, they may protect others from you if you aren’t very infectious at the moment, (K)N95 masks not only protect others from you (particularly if they don ‘t have an exhalation valve) but also protect you from others. The way to stop this pandemic is the way to do anything, one small step at a time, consistently- wear your (K)N95 mask every time you go out. Use common sense, it will save your life.