Why Face Masks Don’t Work, According To Science

[–]whereswhat 4 insightful - 1 fun4 insightful - 0 fun5 insightful - 0 fun5 insightful - 1 fun - 3 years ago (15 children)

[–]fred_red_beans[S] 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago* (14 children)

Last I checked, calling something horseshit doesn't qualify as science. It may qualify as an emotional response perhaps, but not science.

Yes, the first two studies Ben cites are comparisons of N95 masks vs medical masks. Remember, the N95 mask was called an essential health care item to supposedly slow the spread of COVID-19. These studies show the N95 mask is no better than a standard surgical mask.

2019: https://jamanetwork.com/journals/jama/fullarticle/2749214

This study states that neither mask has been shown to be effective in prevention of viral infections:

Clinical studies have been inconclusive about the effectiveness of N95 respirators and medical masks in preventing health care personnel (HCP) from acquiring workplace viral respiratory infections.

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

2020: https://onlinelibrary.wiley.com/doi/epdf/10.1111/jebm.12381

Previous meta-analyses concluded that there was insufficient evidence to determine the effect of N95 respirators.

The use of N95 respirators compared with surgical masks is not associated with a lower risk of laboratory-confirmed influenza. It suggests that N95 respirators should not be recommended for general public and nonhigh-risk medical staff those are not in close contact with influenza patients or suspected patients.

Although N95 respirators may confer superior protection in laboratory studies designing to achieve 100% intervention adherence, the routine use of N95 respirators seems to be less acceptable due to more significant discomfort in real-world practice. Therefore, the benefit of N95 respirators of fitting tightly to faces is offset or subjugated. However, it should be noted that the surgical masks are primarily designed to protect the environment from the wearer, whereas the respirators are supposed to protect the wearer from the environment.

The third study is concerned with the effectiveness of cloth masks in the general population:

2015: https://bmjopen.bmj.com/content/5/4/e006577

The aim of this study was to compare the efficacy of cloth masks to medical masks in hospital healthcare workers

The rates of all infection outcomes were highest in the cloth mask arm, with the rate of ILI statistically significantly higher in the cloth mask arm compared with the medical mask arm.

This study is the first RCT of cloth masks, and the results caution against the use of cloth masks. This is an important finding to inform occupational health and safety. Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection.

The following study does compare masks vs no mask:

2009: https://pubmed.ncbi.nlm.nih.gov/19216002/

Health care workers in a tertiary care hospital in Japan were randomized into 2 groups: 1 that wore face masks and 1 that did not.

Face mask use in health care workers has not been demonstrated to provide benefit in terms of cold symptoms or getting colds.

More importantly, RT news is funded by the Russian government.

This is just ad hominem.

[–]whereswhat 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago (13 children)

There is nothing in the cited sources that even claims "masks don't work", yet the title of the video is "Why face masks dont work, according to science".

Face mask use in health care workers has not been demonstrated to provide benefit in terms of cold symptoms or getting colds. A larger study is needed to definitively establish noninferiority of no mask use.

FTFY. And for the larger study:

-Side note-

A Japanese study had only 32 subjects, and likely was underpowered to find any difference between masks and control (Jacobs et al., 2009).

-Conclusion excerpt-

In the community, masks appeared to be effective with and without hand hygiene, and both together are more protective.

More importantly, RT news is funded by the Russian government.

This is just ad hominem.

You're damn right it is. However, ad hominem is valid when the claimant's character or background has a specific bearing on the matter being discussed. For instance, if you're debating about an ethical issue involving a corporation and that person has stock in the corporation, then your argument would have validity.

[–]fred_red_beans[S] 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago* (12 children)

You're asserting that even though there's no evidence that masks do in fact work, we should just go along with it? Even though it could be just as effective as wearing purple socks? You feel we need to prove that not wearing a face mask is just as good wearing a face mask in order to not wear a face mask (noninferiority)?

https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article

In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks

There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure. Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.

You're damn right it is. However, ad hominem is valid when the claimant's character or background has a specific bearing on the matter being discussed. For instance, if you're debating about an ethical issue involving a corporation and that person has stock in the corporation, then your argument would have validity.

Wow, an article to fight those nasty conspiracy theorists, lol. I'm sorry you feel you are unable to critically evaluate information for yourself and feel you need to rely on an authority.

Ad hominem arguments here on Saidit are considered low on the Pyramid of Debate. Your attack of the authority of RT is not really relevant to the topic. I believe CNN, MSNBC, Fox News, et al spread propaganda and misinformation. That doesn't mean I ignore their coverage or discount everything they report. I use critical thinking to discern between opinions and facts. Do you feel the studies cited are somehow Russian propaganda?

Can you cite any studies or randomized controlled trials (RCT) that show face masks help reduce the spread of viruses in the general population (not just health care workers)?

[–]whereswhat 2 insightful - 2 fun2 insightful - 1 fun3 insightful - 1 fun3 insightful - 2 fun - 3 years ago (11 children)

Can you cite any studies or randomized controlled trials (RCT) that show face masks help reduce the spread of viruses in the general population (not just health care workers)?

Use your brain, of course masks help in the general public. If the space you are occupying is not completely contaminated, then reducing the reach of one's breath is a sound strategy for transmission prevention in theory and in practice. I suggest you actually read the latest research on the topic (which I already cited in my last comment):

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/#!po=19.5652):

In the community, masks appeared to be effective with and without hand hygiene, and both together are more protective.

Also, yes, I realize ad hominem is low on the pyramid. Sorry for offending you so badly. My argument is not founded on this ad hominem though and I am happy to hash out the science with you if you like.

[–]noice 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago* (4 children)

edit: I'm not OP

Thanks for posting the article. Digging into only a few details and I'm gonna call some shit out. It's not clear-cut as you'd say.

This is the evidence from your review that I will be picking apart:

A trial of 105 sick patients wearing a mask (or no mask) in the household found no significant difference between arms (Canini et al., 2010). However, the trial was terminated prematurely and did not meet recruitment targets, so was probably underpowered. One randomised controlled trial was conducted among Hajj pilgrims, with both well and sick pilgrims wearing masks, and low rates of ILI were reported among contact of mask pilgrims (Barasheed et al., 2014). Our randomised controlled trial is the largest available with clinical endpoints, and studied 245 patients randomised to mask or control (MacIntyre et al., 2016).

Looking into Barasheed et al. 2014, a p-val of 0.04 with that small of a sample size is not much proof, and the authors don't claim much either:

less contacts became symptomatic in the 'mask' tents compared to the 'control' tents (31% versus 53%, p= 0.04). However, laboratory results did not show any difference between the two groups. This pilot study shows that a large trial to assess the effectiveness of facemasks use at Hajj is feasible.

Looking into MacIntyre et al. (their own study from 2016), and I smell something fishy - a post-hoc analysis.

A total of 43 index cases in the control arm also used a mask during the study period (at least 1 hour per day) and 7 index cases in the masks arm did not use a mask at all, so a post hoc sensitivity analysis was carried out to compare outcomes among household members of index cases who used a mask (hereafter ‘mask group’) with those of index cases who did not use a mask (hereafter ‘no-mask group’).

Hmmmm. Characterization of 'with mask' = at least 1 hr per day. Why would we throw those into a mask-wearing group, and why would the results be this without doing so:

There was no significant difference between arms

I think that Canini et al. which showed no significant difference, which McIntyre say may be underpowered, is more compelling than a sketchy post-hoc analysis on a slightly higher number of subjects.

[–]whereswhat 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 0 fun2 insightful - 1 fun - 3 years ago (3 children)

I appreciate your attention to detail but I disagree with your conclusion:

I think that Canini et al. which showed no significant difference, which McIntyre say may be underpowered, is more compelling than a sketchy post-hoc analysis on a slightly higher number of subjects.

McIntyre already had shown a statistically significant difference between the groups. Therefore, a post-hoc analysis is required to optimally constrain the empistemic error. Failure to do so would leave unchecked error because some of the control group members actually did have masks on for a small part of the time and some in the masks group did not actually wear a mask. It doesn't mean that everyone in the masks groups only wore a mask for 1 hour. It was intended to ensure that the different groups were properly defined and that the binning did not skew the results in a significant way.

Canini et al. was clearly underpowered. Here is the conclusion summary from the article itself:

This study should be interpreted with caution since the lack of statistical power prevents us to draw formal conclusion regarding effectiveness of facemasks in the context of a seasonal epidemic.

Statistical power is closed form quanitative metric. Here we have one study (McIntyre) which has very high power and has been validated with a post-hoc analysis and another (Canini) which has low power and therefore does not warrant post-hoc analysis. I am going to trust the former over the latter, just like the authors suggest.

[–]noice 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago* (2 children)

Are we looking at the same paper?

The Kaplan-Meier curves showed no significant differences in the outcomes between two arms (p>0.050; figure 2).

There was no association between mask use by the index cases and rates of infectious outcomes in household members (table 3). Although the risks of CRI, ... ILI..., and laboratory-confirmed viral infections were lower in the mask arm, the difference was not statistically significant.

It's not until they conduct the post hoc analysis that they see a statistical difference.

I'm not suggesting that everyone in the mask group only wore the mask for 1 hr. I'm saying that their study as designed found no statistical difference, and then they found a way to achieve statistical significance by afterward moving more (based on the numbers, non-event) subjects into the mask group.

[–]whereswhat 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 0 fun2 insightful - 1 fun - 3 years ago (1 child)

[–]noice 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago (0 children)

[–]fred_red_beans[S] 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago (5 children)

The article you refrence:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7191274/#!po=19.5652):

was done post covid panic, and I suspect this post covid timing may have caused bias. It refrences 19 prior studies.

I am not finding one study refrenced that shows statistical evidence of a benefit of wearing masks in terms of risk of getting a viral respiratory disease.

In the article you refrence, it states:

In the community, masks appear to be effective with and without hand hygiene, and both together are more protective (Aiello et al., 2012; Aiello et al., 2010; MacIntyre et al., 2009)

But none of those studies show statistical evidence as such.

Aiello et al., 2012

We examined the efficacy of face masks and hand hygiene for reducing the incidence of ILI and laboratory-confirmed influenza in an open, non-institutionalized population of young adults. Our findings show a significant reduction in the rate of ILI among participants randomized to the face mask and hand hygiene intervention during the latter half of the study period, ranging from 48% to 75% when compared to the control group. We also observed a substantial (43%) reduction in the incidence of influenza infection in the face mask and hand hygiene group compared to the control, but this estimate was not statistically significant. There were no substantial reductions in ILI or laboratory-confirmed influenza in the face mask only group compared to the control.

Simmerman et al., 2011

Influenza transmission was not reduced by interventions to promote hand washing and face mask use.

Larson et al., 2010

In this population, there was no detectable additional benefit of hand sanitizer or face masks over targeted education on overall rates of URIs, but mask wearing was associated with reduced secondary transmission and should be encouraged during outbreak situations.

Based on previous data and our finding that there were significantly more people in the Hand Sanitizer group who reported no symptoms at all during the course of this study, it is possible that alcohol-based hand hygiene may offer some protection against URIs in the community. However, the relatively small number of individuals studied to date has not been adequate to provide an estimate of effect size and, overall, there were no differences in infection rates among the intervention groups. Mask wearing is a promising non-pharmaceutical intervention to reduce risk of secondary transmission of viral URI, but it is likely that adherence to mask wearing would occur only if there was a major pandemic that resulted in a heightened level of community concern and fear.

Aiello et al., 2010

We observed significant reductions in ILI during weeks 4-6 in the mask and hand hygiene group, compared with the control group, ranging from 35% (confidence interval [CI], 9%-53%) to 51% (CI, 13%-73%), after adjusting for vaccination and other covariates. Face mask use alone showed a similar reduction in ILI compared with the control group, but adjusted estimates were not statistically significant. Neither face mask use and hand hygiene nor face mask use alone was associated with a significant reduction in the rate of ILI cumulatively.

MacIntyre et al., 2009

During the 2006 and 2007 winter seasons, 286 exposed adults from 143 households who had been exposed to a child with clinical respiratory illness were recruited. Intent-to-treat analysis showed no significant difference in the relative risk of ILI in the mask use groups compared with the control group; however, <50% of those in the mask use groups reported wearing masks most of the time.

The main transmission route for these viral respiratory diseases is very fine aerosol particles that are supported as part of the fluid air. These particles are so fine that they can make their way around any mask through the wrinkles in skin etc. It is known that masks can not prevent transmission of these very fine particles. Transmissivity is high in the winter as the humidity is low and the particles stabilize in the air, while in the summer when the humidity is higher transmissivity drops by a factor of 4 or 5. Transmission primarily occurs in buildings in the winter with particles suspended in the air.

[–]whereswhat 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago (3 children)

I want to thank you again for sticking to reputable sources and scrutinizing in an honest way. If OP had shared something similar to your latest comment, I would not have left such a scathing response.

While I still do not agree with your final conclusion, I will concede that anything done post covid panic should be subject to extra scrutiny.

The main transmission route for these viral respiratory diseases is very fine aerosol particles that are supported as part of the fluid air. These particles are so fine that they can make their way around any mask through the wrinkles in skin etc. It is known that masks can not prevent transmission of these very fine particles. Transmissivity is high in the winter as the humidity is low and the particles stabilize in the air, while in the summer when the humidity is higher transmissivity drops by a factor of 4 or 5. Transmission primarily occurs in buildings in the winter with particles suspended in the air.

100% correct. Fact is, masks do nothing when the local environment is already contaminated. I find it concerning how the general population seems so unaware of this.

In the situation where the local environment is clean (i.e. no virus matter), wearing a face mask will reduce spread because "the main transmission route for these viral respiratory diseases is very fine aerosol particles that are supported as part of the fluid air". Hence, when an infected person breathes in a clean environment, limiting the distance that their breath travels from their face also limits the volume of space in which transmission might occur.

I agree that more informative studies on the topic would be easy to conceive but I do believe my claims above are supported by the, albiet slightly flawed, existing literature.

In the community, masks appear to be effective with and without hand hygiene, and both together are more protective (Aiello et al., 2012; Aiello et al., 2010; MacIntyre et al., 2009)

But none of those studies show statistical evidence as such.

I agree that individually, nither of the Aiello studies hold up very well. The MacIntyre study from 2009 is better but still has shortcomings. However, the collation of all this data and the added post-hoc analysis in the review I cited does show statistical significance.

The Simmerman study's own authors point out that their study cannot be relied upon alone. I also detect a hint of bias in your interpretation of the Larson findings:

In this population, there was no detectable additional benefit of hand sanitizer or face masks over targeted education on overall rates of URIs, but mask wearing was associated with reduced secondary transmission and should be encouraged during outbreak situations.

[–]fred_red_beans[S] 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago (2 children)

In the situation where the local environment is clean (i.e. no virus matter), wearing a face mask will reduce spread because "the main transmission route for these viral respiratory diseases is very fine aerosol particles that are supported as part of the fluid air". Hence, when an infected person breathes in a clean environment, limiting the distance that their breath travels from their face also limits the volume of space in which transmission might occur.

With the particles being suspended in air, wouldn't the virus particles that are expelled seek equilibrium in the air of an enclosed space? I could see the mask keeping the concentration higher on the inside of the mask of the infected wearer while not completely stopping virus particles from being expelled into the surrounding area. The mask will certainly do something. Is it beneficial for the general population to wear a mask? I don't see that it is, but I think it makes sense those for who are at risk to take precautions.

I think the mask mandates and the lockdowns are primarily exercises in adherence to authority and control. There is no historical precedent or clear science that shows these actions are necessary. The death rate was touted to be 3-4% without taking any asymptomatic cases into account, which in the case of influenza the asymptomatic cases to confirmed cases is 36 million to 220,000 which without taking those cases into account would result in the flu having a death rate of 10%. I know this is a bit off topic of masks, but I have to seriously doubt statements from the WHO and the CDC on this issue when it is their job to gauge and track these diseases and they had to know 3-4% was wrong.

Thank you for posting informative sources. While we may disagree, I think I've gone through more scientific studies than I have in a while.

[–]whereswhat 2 insightful - 1 fun2 insightful - 0 fun3 insightful - 0 fun3 insightful - 1 fun - 3 years ago (0 children)

With the particles being suspended in air, wouldn't the virus particles that are expelled seek equilibrium in the air of an enclosed space?

Virus particles will diffuse into the surrounding environment at the exact same rate as the breath of air on which they are hitching a ride. The diffusion pattern depends on initial velocity, turbulence, and total volume of the exhaled breath. The presence of a mask reduces initial velocity and increases turbulence (volume of breath unaffected obviously). Both of these effects reduce the rate of diffusion. That is the mechanistic reason why masks are helpful.

Side note: I fucking love fluid dynamics :)

I could see the mask keeping the concentration higher on the inside of the mask of the infected wearer while not completely stopping virus particles from being expelled into the surrounding area.

Correct.

The mask will certainly do something. Is it beneficial for the general population to wear a mask? I don't see that it is, but I think it makes sense those for who are at risk to take precautions.

Remember that anything less than an N95 mask is not meant to protect the wearer so much as the people nearby though.

I agree that the mortality rate is wildly inflated for COVID. That said, the hospital down the street from me has been at capacity for months now so there is definitely a motivation to reduce the rate of spread.

I have mad respect for you keeping your cool and grinding through all this. It has been fun to read these articles.

[–]Jesus 2 insightful - 2 fun2 insightful - 1 fun3 insightful - 1 fun3 insightful - 2 fun - 3 years ago (0 children)

[–]avena_sativa_3 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago (1 child)

[–]noice 3 insightful - 1 fun3 insightful - 0 fun4 insightful - 0 fun4 insightful - 1 fun - 3 years ago (0 children)

[–]fred_red_beans[S] 1 insightful - 1 fun1 insightful - 0 fun2 insightful - 0 fun2 insightful - 1 fun - 3 years ago (0 children)

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