Let me start this off by saying, I dont care if you want to wear a mask. If you feel better doing it, by all means do it. I am not against mask usage. I am against being forced to wear one and shamed for not wearing one. This article is to show that I’m not “killing someone’s grandma” by not wearing one. It also doesnt mean I am advocating for hospital workers to not wear one when in sterile environments. They’re worn in hospital settings to fulfill the need to protect people from bacterial infections!
This study that I’ve linked in this post, was a study conducted to test the efficacy of cloth masks of different materials against different sized aerosolized particles.
As you can see in the infographic provided, the size of SARS-cov-2 is 120nm, very tiny compared to a 1,000nm bacteria (which is what surgical masks are supposed to be protection against). The mission behind this study, as stated in the study, is to, “conduct research on the effectiveness of woven cloth masks for the transmission of influenza virus because cloth masks may be the only option available for some individuals during a pandemic. Research on alternative respiratory protective materials, including common fabric materials such as T-shirts, handkerchiefs, and scarves, was also recommended.”
They even state in the study, “These household materials are NOT designed for respiratory protection and their use may provide a false sense of protection.”
The conclusion reached was that, “results obtained in the study show that common fabric materials may provide MARGINAL protection against nanoparticles including those in the size ranges of virus-containing particles in exhaled breath.”
Furthermore, “the use of fabric materials may provide only minimal levels of respiratory protection […] against virus-size submicron aerosol particles (e.g. droplet nuclei). This is partly because fabric materials show only MARGINAL filtration performance against virus-size particles when sealed around the edges. Face seal leakage will FURTHER DECREASE the respiratory protection offered by fabric materials.”
The charts I provided show the efficiency of the different types of cloth masks at two different (realistic) velocities. You can see the control for penetration levels being the N95 masks. The cloth masks are nowhere near the protection people are assuming it gives. They found that the “average penetration levels for the three different cloth masks were between 74 and 90%, while N95 filter media controls showed 0.12%”. This is a CLEAR difference between effectiveness of the cloth vs N95. In the reverse, that means the N95 mask filters 99.88% of particles while the cloth masks range from particle filtration levels of 10-26%!
Ultimately, the “penetration levels for these fabric materials against polydisperse, as well as monodisperse aerosols, were MUCH HIGHER than the values for the control N95 respirator filter media. A POOR filtration performance is expected for improvised fabric materials because these materials are NOT designed for respiratory protection.” Though efficiency increased for larger particles (bacteria sized), 74-90% of virus sized particles were able to penetrate the cloth masks.
Also, surgical masks are comparable in efficiency as stated and sourced in the article, “the filtration efficiency of improvised fabric materials is comparable to some commonly used Federal Drug Agency-cleared surgical masks and unapproved dust masks“, which is probably why the surgical mask boxes are clearly marked as not for use in protection against COVID-19.