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AngryCanary -4 points ago +2 / -6

Except the sourced studies were very poor and the author got basic information wrong. For example, the meta analysis wasn't even a meta analysis by their own admission and hand selected only 12 studies out of 279 papers, including an under-powered study and one from 1918.

The other problem, is I've personally read papers that the author denies exists, such as a study which looked at the protective efficacy of masks when worn while a family member is sick. I actually read that study and it clearly showed that among the families with mask adherence there was a greatly reduced risk of contracting the flu. These studies he mentioned also didn't address the multiplicative effectiveness of masks or "herd immunity", which many studies have found. Rather, they only looked at a few inconclusive studies which attempted to determine whether wearing a mask protects the wearer. This doesn't necessarily relate to the effectiveness of mask use as public policy, and even the review he linked admitted that there is evidence for this.

He also got the basic material science on masks wrong, claiming that small particles can not be stopped because masks are rated for pm2.5 sized particles, analogous to a strainer. The reality is masks are most effective at stopping very small particles and very large particles due to electrostatic forces. It's actually the PM2.5, medium sized particles which are hardest to stop because they are small enough to fit through fibers while being large enough that they can escape electrostatic forces, which is why masks are bench-marked in pm2.5.

There are some other fallacies, such as minimum effective dose, which I won't get into, but suffice to say the larger the inoculate, the more likely you are to get sick and the higher the chance of developing serious symptoms. Also, it ignores the math of epidemiology. In other words, you don't need to prevent all infections to wipe out a disease. You only need to reduce its transmission rate below 1, meaning the average infected person infects on average less than 1 new person. Drawing an example, that means if combined measures reduce the transmission of a disease with a transmission rate of 2 by 60%, you would not simply have 60% fewer cases, you would essentially eliminate community spread as new infections trend towards zero.

In summary, the thesis that "The Science is Conclusive: Masks and Respirators do NOT Prevent Transmission of Viruses" is patently false, and even the linked studies do not make that assertion.

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LessSwampMoreMAGA 5 points ago +6 / -1

In summary: You complain about sources yet you cite none.

And you literally are proving my point that your arguing mechanisms without (1) data that shows masks significantly reduce infection rate in the population (2) is a result of a asymptomatic carriers wearing said masks and (3) results in fewer deaths in the population being studied as a DIRECT result of the illness.

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AngryCanary 1 point ago +4 / -3

Masks reduce the chance of contracting a respiratory infection by up to 80% for the wearer. These are some studies I went through several months ago, there are many more now but I don't feel like spending my evening collecting links which you could find yourself if you actually bothered looking.

National Institutes of Health http://archive.is/5Vm12

Home-made cloth masks reduce permeation even of tiny 0.02 µm–1 µm particles by 50%, with surgical masks reducing permeation by 75% even during real-world activities.

Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection.

International Journal of Infectious Diseases http://archive.is/1Mwcb

Surgical masks prevent the wearer from being infected when living with someone who has the flu.

In compliant users, masks were highly efficacious.

role of facemasks and hand hygiene in the prevention of influenza transmission in households: results from a cluster randomised trial; https://www.ncbi.nlm.nih.gov/pubmed/22280120

Results suggest that household transmission of influenza can be reduced by the use of NPI, such as facemasks and intensified hand hygiene, when implemented early and used diligently.

Facemasks and hand hygiene to prevent influenza transmission in households: a cluster randomized trial.https://www.ncbi.nlm.nih.gov/pubmed/19652172

Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset.

Mask use, hand hygiene, and seasonal influenza-like illness among young adults: a randomized intervention trial.https://www.ncbi.nlm.nih.gov/pubmed/20088690

These findings suggest that face masks and hand hygiene may reduce respiratory illnesses in shared living settings and mitigate the impact of the influenza A(H1N1) pandemic.

Journal of the American Medical Association http://archive.is/cvUQ7

This study of 446 nurses in Ontario hospitals showed that n95 masks and surgical masks offered similar protection from viral infection for the wearer.

National Institutes of Health http://archive.is/GMOaG

Surgical masks offer almost as effective filtration efficiency against simulated particles as n95 masks.

Emerging Infectious Diseases (the journal of the CDC) http://archive.is/spCh6

adherent mask users had a significant reduction in the risk for clinical infection.

Modeling the Effectiveness of Respiratory Protective Devices in Reducing Influenza Outbreak https://pubmed.ncbi.nlm.nih.gov/30229968/

a 50% compliance in donning the device resulted in a significant (at least 50% prevalence and 20% cumulative incidence) reduction in risk for fitted and unfitted N95 respirators, high‐filtration surgical masks, and both low‐filtration and high‐filtration pediatric masks.

An 80% compliance rate essentially eliminated the influenza outbreak.

Influenza Virus Aerosols in Human Exhaled Breath: Particle Size, Culturability, and Effect of Surgical Masks https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/

11% vs 43% efficacy of masks (no mask vs mask)

Physical interventions to interrupt or reduce the spread of respiratory viruses https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6993921/

Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis https://onlinelibrary.wiley.com/doi/pdf/10.1111/jebm.12381

The sensitivity analysis after excluding the trial by Loeb et al18 showed a significant effect of N95 respirators on preventing respiratory viral infections (RR=0.61, 95% CI 0.39-0.98, P < .05). A similar effect was observed for surgical masks.

Simple Respiratory Mask https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3373043/

Quality commercial masks are not always accessible, but anecdotal evidence has showed that handmade masks of cotton gauze were protective in military barracks and in healthcare workers during the Manchurian epidemic.

What Hospitals Should Do to Prepare for an Influenza Pandemic https://www.liebertpub.com/doi/pdfplus/10.1089/bsp.2006.4.397

Use of simple surgical masks limit accidental droplet contamination in a hospital environment (staff, patients, and visitors).

If no other masks are available, surgical masks, which will provide droplet protection, should be used.

How effective are face masks in operation theatre? A time frame analysis and recommendation https://www.ijic.info/article/view/10788/7862

study helps to establish that in developing countries, where resources could be a constraint for providing disposable face masks, the fabric face masks can also be used equally effectively

N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel https://jamanetwork.com/journals/jama/article-abstract/2749214

N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza.

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SininStyle 2 points ago +2 / -0

Adult conversation, supplied loads of citation as requested, dont see the point in down voting. Wish more conversations resulted in this regardless of the topic or agreement. So thanks for that.