A month ago or so, I made a blog on masks and why I believe that universal masking is a good thing. Check that blog out – I feel that it was a good one and I had some nice feedback on that, but at the same time I've got some controversial thought and images to think about. So today I would like to dispel some myths and to do some experiments with masks. For the greater good of course.
1. Using the mask against the virus is the same thing as using a fence against mosquitoes
This statement is a huge exaggeration. Mosquitoes are hundred times smaller than the fence holes and they can maneuver through them. Viruses don't have such ability and they are just several times smaller than the holes in the mask. There are several layers in a typical surgical mask and these layers create a meshwork of fibers that is much harder to penetrate. Plus, at such small sizes even electrostatic forces can repel the virions or stick them to the fibers of the mask. So, sorry, but this meme doesn't make much sense.
2. Virologists use hazmat suits to protect themselves against viruses, but don't worry your mask works too
Yes, your does mask work too! Research shows that it does, and nobody says that it helps to the same extent as a hazmat suit. A hazmat suit would protect you with close to 100% guarantee, and while masks offer much, much lower protection level, they are affordable and you can wear them as much as you need and they are available to everyone. Even virologists cannot wear their suits 24/7, and obviously we cannot supply everyone with one. So, masks, especially N95s or surgical masks, are the most cost-effective way to protect us as a community – they are cheap, easily accessible and offer a decent level of protection. In addition to that, the goal of the universal masking is not so much to protect individuals, but to protect the community via source control.
3. Research "shows" that masks do not provide protection against the virus. There was a meta-analysis.
This is the meta-analysis everybody is talking about: Yong et al, 2020. Let's read the title – "Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis"1. I think that anyone who can read can tell that they are comparing n95 masks to surgical masks and, if you read the abstract, they found that n95s are not statistically better than surgical masks for protection from the virus. We are not even talking about comparisons to no mask at all and the use of masks for source control. So, the whole statement is completely misconstrued!
If you want to read research specifically on masks protecting you from influenza, SARS and SARS-CoV-2, Yours truly would recommend reading this meta-analysis of studies focused specifically on that question. The authors found 21 studies and the pooled data indicated that masks reduce the risk of transmission in healthcare workers by 80% and in non-healthcare workers – by 47%2. Convincing enough, eh?
4. Jeans can't stop farts, but you expect a cloth mask to stop the virus
This is getting silly, honestly. The gases you can smell in someone's flatulence are very simple molecules. For example, one molecule of methanthiol, the gas that conveys that unholy smell to intestinal gases, is 0.4nm in size, which is ~200 times smaller than the virus particle, which is around 125 nm (60-140 nm). Of course, clothes do not stop the passage of such small particles. Which brings us to our next items – the most important gases in our life.
5. Masks deprive you of oxygen
This is not true and if someone believes that masks cannot stop the virus, they simply can't believe that they stop oxygen somehow. This is easily testable – I did this experiment on myself, check it out in the video. You put a pulse oximeter on your finger and test your oxygen saturation. It doesn't change whether you wear a mask or not. There were multiple videos of doctors doing it, check them out too if you don't believe me. As a medical doctor, I must say though, that masks can affect airflow and that might lead to some detrimental effects, especially in people who are wearing the masks during strenuous exercise or people with cardiovascular or respiratory diseases.
6. Masks just deflect the airflow
This statement is actually very interesting – there are videos of people vaping and putting a mask on before exhaling. And it's obvious that the vapour goes out in all directions. I must say that evidence like that does show that masks might not be as effective as we think. But, first of all, the vapour doesn't go straight – it goes up and down and to the sides, so you are less likely to exhale virions directly on others. Another aspect of it is that we don't know how much of the vapour stays in the mask and whether masks filter the exhaled air so well that all the vaping particles that go through the mask are being effectively caught by it. This is definitely a subject for further research.
7. Masks lead to a buildup of CO2
This sounded questionable as since we know that oxygen freely passes through masks, they shouldn't stop CO2 from passing either. There is a video of a teacher who uses a CO2 detector to test it and indeed it shows that there is a build up of CO2 inside the mask. I was wondering whether this effect is due to the proximity of the sensor to the mouth and what would be the outcome without a mask. So, I tested it myself and it turns out that there is indeed a buildup of CO2 inside the mask, but it's not really higher than the concentration of CO2 if you test it without the mask – by just putting the sensor next to your mouth when speaking. I wish I could test CO2 levels in the blood, but I don't have tools for that. I found a video of a doctor showing that the blood CO2 levels do not go up when wearing a mask, which is a relief, but since I'm a nerd, I know that our bodies have a way of converting CO2 into carbonic acid using carbonic anhydrase. So, the sole video on that subject that I found might be misleading and this should also be researched further.
There is still a lot of misinformation, but I hope that you can see that a lot of the memes and "smart" remarks about the masks are simply untrue. There are clearly some things that need to be researched, such as the carbon dioxide buildup and overall effects on airflow and health in general as well as the safety of wearing masks in people who are vulnerable. But in general, it should not prevent the vast majority of people from wearing masks when at social gatherings and when physical distancing is not possible.
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 to subscribe 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. Long Y, Hu T, Liu L, et al. Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis. J Evid Based Med. 2020;13(2):93-101.
2. Liang M, Gao L, Cheng C, et al. Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis. Travel Med Infect Dis. 2020:101751.