In the last several weeks masks became a subject of heated and emotional discussions, polar and even controversial opinions. I've seen a lot of videos and talks on masks with polar opinions ranging from "masks don't help at all and are oppressive" to "masks should be mandatory for everyone". I feel that, as a medical doctor, I should talk about masks in this series. I had couple of catchy titles for this blog like "Safety masquerade" or "Masking the problem", but I chose to stick to a very neutral one as the subject already became quite sensitive and controversial and I don't want to add any drama to it.
The timeline of events
I understand where the controversy and high emotions are coming from – first we were told by WHO that masks are not needed, and we were literally advised not to wear them. All the arguments against masks were brought up with some research evidence stating that wearing masks makes people touch their face more and people might be wearing them wrong among other reasons not to wear them. Then, we had a statement that there was a shortage of masks and the public health officials were saving them for health care professionals. That definitely wasn't helpful – I see how it affected the credibility of public health experts and authorities. After that, masks have been heavily promoted to the point of suggesting that they should be mandatory. They also became a prerequisite for re-opening of businesses, including places like gyms and dental offices, places where it didn't even make sense to wear masks, which sparked a wave of public discontent with these measures. I still believe that universal masking does more good than harm, so let's straighten things out.
Are masks helpful?
There were tons of memes about masks based on the size of the virus and the filtering capacity of the commonly used masks. In part it was fueled by earlier statements by doctors and public health officials that masks do not protect from coronavirus. Even the mask packaging itself clearly states that they will not protect you from COVID-19. So where is the truth?
The truth is that the masks indeed cannot give you a 100% protection from coronavirus. But they do offer a substantial reduction in the number of viral particles (virions) you inhale. Yes, the virus is very small – the typical size of coronavirus is around 0.125 nm and the minimum protection factors were observed for particle sizes of 0.263-0.384 nm1. But there is much more than just filtering that masks do – there are electrostatic effects, diffusion, and deflection of viral particles. Also, we have to keep in mind that the virus often travels in droplets that we produce when talking, coughing, singing or even breathing, and these droplets are much larger than the virus, but they are also much less likely to permeate the masks.
The data that I've seen show that n95 masks reduce the number of particles inhaled by 97.5% - which means that only 2.5% of viral particles will be inhaled. Surgical masks catch 63% of particles, so only 37% of them will be inhaled, which is still almost 3 times less than without wearing a mask. Of note, there is a commonly cited statistic stating that surgical masks are 10-15 less effective than n95s – indeed 37% is approximately 10-15 times less than 2.5-5%, but, again, it doesn't mean that surgical masks are useless. Cloth masks offer only 28% reduction, which is still better than nothing, but I would suggest using surgical masks whenever they are available.
At the end of the day, the question that I would like you to ask yourselves is "would you wear some protection, or none at all?". I hope that the answer is in favour of mask wearing, at least in crowded places.
Masks as a public health measure
Another important consideration is that the main purpose of wearing masks is not to protect individuals, but rather to protect communities. First of all, the masks are excellent in catching the droplets that we produce and the virus into the air on top of reducing its inhalation. And there is a compounding effect – assuming that all of us wear masks there is much less virus particles being released into the air, and then even smaller number are being inhaled, so the overall amounts of virus being transmitted will be drastically reduced and the transmission rates will be much lower.
We've been focusing on coronavirus so far, but there are other viruses, bacteria and pollutants in the air, which we can protect ourselves against by wearing masks. I doubt that anyone would choose not to wear a mask in a dusty environment, and I don't think you need any scientific proof of that. Wearing a mask protects you from all kinds of detrimental external particles and it should not be discounted.
Negative effects of masks
It wouldn't be fair if we just spoke about the positive effects of masks – a lot of people voiced their concerns about breathing difficulties while wearing masks, lack of oxygen, and carbon dioxide poisoning. Let me address it. First of all, oxygen and carbon dioxide are much smaller than the virus and these gases can freely permeate through any masks. But, masks indeed create an additional resistance to air flow and wearing them can be problematic for certain categories of people – those with heart and lung disease and people who are exercising very intensely, at or above their maximal oxygen uptake. But, for the rest of the people i.e. healthy individuals engaging in light activities masks should not be a problem. I tested my oxygen saturation with and without a mask, just to be sure about it, and there was no difference. Also, some people are wearing masks as part of their training regimen to improve their performance, and we can do the same to use restrictions to our advantage.
I hope that I was convincing enough, and you see how universal masking helps with slowing down the transmission of the virus and flattening the curve. At the same time, there are certain side effects, potential or real for some people, so I would recommend that communities, businesses and individuals use discretion when choosing whether to wear masks or not. Again, I believe that masks are very helpful, and we should try to wear them whenever possible and comfortable. I would definitely wear one in a crowded space, and I do wear them at work, in a hospital.
As always, I would like to remind you that this blog should not be taken as medical advice and that my opinions do not necessarily represent the official standing of regulatory and public health authorities. At the same time, I believe that my points are valid, and I would like to encourage you subscribing to this website, and to my YouTube channel. You are also always welcome to communicate with me via making comments, suggestions, and asking questions, either here, or on social media platforms.
Stay safe, strong, and healthy!
1. Lee S-A, Hwang D-C, Li H-Y, Tsai C-F, Chen C-W, Chen J-K. Particle Size-Selective Assessment of Protection of European Standard FFP Respirators and Surgical Masks against Particles-Tested with Human Subjects. Journal of Healthcare Engineering. 2016;2016:8572493.