Masks: unmasking myths
Whether it’s a 10 day mask mandate in Brissy or more of a year long journey in Melbourne, wearing a mask is becoming the new normal. The sudden shift has left the general public wondering; do they even work? Are some better than others? Should I be double masking? Does my mask match my outfit? All are answered below, according to science…
So, how do masks work?
The main purpose of mask wearing is “source control”, which basically means preventing a sick patient transmitting the virus to other non-sick people. Transmission of COVID-19 happens via little droplets and aerosols (super tiny droplets) being ejected from your mouth when speaking, coughing, sneezing or screaming the lyrics to WAP. The most common droplet size is between 5μm to 10μm (where 1μm is 1000x smaller than a millimetre). When speaking, the expelled droplets become smaller and smaller and become aerosols (droplets smaller than 5μm), which can float through the air for longer, infecting more things in its path. Evidence has emerged showing loud talkers create larger droplets and therefore more virus stuff (sorry loud talking extroverts!) We want to prevent aerosols as much as we can and wearing a mask stops droplets from escaping and sailing through the air like tiny, evil assassins. Studies have also found patients are most infectious during the first initial stages of having the virus. This is when the patient has little to no symptoms presented and thus when wearing a mask is most important. Basically, masks help people keep their nasty droplets to themselves.
How good are masks anyways?
Well the answer is more of a question of “how well you wear a mask”, “what type of mask you are you wearing” and “why is your nose sticking out of your mask, Sharon”? Firstly, it must be said that the effectiveness of mask wearing hinges upon the ability to adhere to all other social distancing and protective measures. Wearing a mask the proper way after coughing into your hand and high fiving your co-worker isn’t helping. The effectiveness of a mask depends on how snugly it fits on your face and what sus pop-up store you bought your fabric mask from. The correct fit of a mask is essential in ensuring droplets aren’t escaping out the sides whilst speaking. The effectiveness also depends on the number of layers within the mask. If your fabric mask has one slightly see through layer, it isn’t doing much. Ideally, cloth masks should have three layers. Despite this, research has found that all masks are somewhat effective in blocking viral transmission and one layer fabric is better than nothing at all. Choosing the correct mask for you and your particular situation is key in doing your part.
Cloth versus surgical: just for doctors?
There are three different types of masks:
N95 (or known as FFP2 in Europe) - N95 is the bees knees of masks! Its snug on your face and gives off that terrifying pandemic look! N95 masks are reserved for those who really need it, the health care workers of the pandemic.
Surgical - They don’t fit as well as N95 but they have three layers of protection and need to be disposed of after one use.
Cloth masks – The idea is there! They are reusable so we aren’t putting more disposable waste into the environment. But for cloth masks to be just as effective as the medical masks, a few things need to happen. The mask needs to be more than just one layer and the mask should be washed daily to eliminate the potential virus clinging to the outer layer of fabric.
Double masking; double as effective?
We’ve been seeing an increase, particularly in the US, of double masking. This is an effective measure when wearing a surgical mask underneath and a homemade mask over the top. This works as it ensures the mask is better secured to your face. The effectiveness of mask wearing is based on how well the mask fits your face. If you are wearing a fabric mask or a surgical mask with the necessary 3 layers of protection and fits snugly to your face with no gaps, double masking is not necessary.
Influenza influencer: is looking cute a downfall?
The CDC continues to recommend the wearing of cloth masks to the general public. Basically, if you’re low risk like we are here in Aus, no need to go out and steal the hospitals stash of N95s. Cloth masks still help to slow the spread, and wearing it with a surgical mask would be the extra mile if you’re still a bit worried. So, go wash your masks because I know it’s been a while!
Howard, J. et.al. (2020) Face Masks Against COVID-19: An Evidence Review. PNAS.
Perié, R and Perié, M. (2020) Analytical and Numerical Investigation of the Airflow in Face Masks used for Protection against COVID-19 Virus – Implications for Mask Design and Usage. Journal of Applied Fluid Medicine.