Do Masks Help in preventing the spread of Coronavirus

A friend contested the efficacy of wearing masks to prevent the spread of Coronavirus. The objection was based on the small size of the virus allowing them to pass through masks. But here is why I don't think that is helpful.

Of course it's fine to ask the question, "Are masks helpful...?" But simply saying that because of the small size of viruses, masks don't work, is ignoring part of the evidence. "The smallest bacteria are about 0.4 micron (one millionth of a meter) in diameter while viruses range in size from 0.02 to 0.25 micron. This makes most viruses submicroscopic," So, sure, they are small. But this doesn't mean that they can't be stopped by a physical barrier.

N95 masks actually do stop most virus infection. But they are not perfect. Surgical masks also stop viruses. But they do it by blocking the aerosol from our breath, not the viruses themselves. And they not near as effective. But they offer a physical barrier. Your "disclaimer" with the Petri dishes was actually meant to show how droplets containing viruses are stopped by using masks. So, you're showing evidence that masks do work in stopping droplets that contains coronavirus.

While you say that you are citing science, you are cherry picking the fact about size and ignoring the fact the physical barriers are actually effective. You're isolating one factor and not taking into accounts other factors. Physical barriers are helpful. The N95s are the best. The surgical masks are next best and most cloth masks, unless they have another barrier inside them are the least.

https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-mask/art-20485449

The overwhelming consensus among people who spend their lives in the field of virology says masks are helpful in preventing the spread of the virus.

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html

https://www.nature.com/articles/s41591-020-0843-2

https://jamanetwork.com/journals/jama/fullarticle/2762694?guestAccessKey=358eefca-92be-44ac-b813-63b5d1744486&utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_content=tfl&utm_term=030420

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/0921A05A69A9419C862FA2F35F819D55/S1935789313000438a.pdf/testing_the_efficacy_of_homemade_masks_would_they_protect_in_an_influenza_pandemic.pdf

So, I'm sorry if you're tired of the debate. But debate is good and it brings out truth. Pushing back by expressing your opinion in fine. However, instead of ignoring the evidence that is out there, there is a case for using the "precautionary principle". That is: "“a strategy for approaching issues of potential harm when extensive scientific knowledge on the matter is lacking.”

https://www.bmj.com/content/bmj/369/bmj.m1435.full.pdf

While studies are not conclusive, the overwhelming consensus as the moment, is that wearing masks in addition to social distancing, tracking and tracing, is helpful in preventing the spread of Coronavirus. I'll be wearing mine when I can't social distance.

Even Mike Pence as started recommending it.

https://people.com/health/mike-pence-encourages-wearing-face-masks-coronavirus/