5 ms·

This study from 2010 is the only one I've ever seen which tests the effectiveness of masks being worn on a face: https://journals.sagepub.com/doi/abs/10.1177/1

This study from 2010 is the only one I've ever seen which tests the effectiveness of masks being worn on a face: https://journals.sagepub.com/doi/abs/10.1177/153567601001500204 https://journals.sagepub.com/doi/abs/10.1177/153567601001500... "The protective efficiencies were 33.3%, 11.3%, and 6.1% for the surgical, bandana, and dust masks, respectively. The N95 mask protective efficiency was 89.6%. In conclusion, the surgical mask protected the best of the three face masks tested. However, it is important to note that all three masks offer very little protection when compared to the N95, and wearing these face masks may produce a false sense of protection."

ketamine__ 6y ago
This randomized trial from 2015 looked at cloth masks. https://bmjopen.bmj.com/content/5/4/e006577 https://bmjopen.bmj.com/content/5/4/e006577 > Conclusions 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. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.
- GaryNumanVevo 6y ago
  Important to note: This study was conducted for _health care workers_. Not the general public. Cloth masks aren't designed to protect the wearer, rather protect everyone else around them by catching droplets / reducing nasal spray / etc. It only works if everyone 95% of people are wearing one, especially indoors.
  - ketamine__ 6y ago
    > It only works if everyone 95% of people are wearing one, especially indoors. If this is the only RCT for cloth masks what kind of evidence is behind your claim? Do you have a source?
  - jlmorton 6y ago
    The linked article is making an assertion that cloth masks protect the wearer by reducing the viral dose, leading to many more asymptomatic cases. It is saying that mask wearing alone is enough to reduce your risk from coronavirus. That is actually the headline from the article: "Cloth masks do protect the wearer – breathing in less coronavirus means you get less sick"
  - misanthropian00 6y ago
    There is no evidence that cloth masks are better at filtering out than they are at filtering in. They are not designed to be one way valves. They are pretty bad at both due to the massive amount of space between threads which virus droplets can just sail right through. No one should be wearing cloth masks if surgical masks are available and no one should be wearing surgical masks when N95 or equiv masks are available. This cannot be repeated enough.
mchusma 6y ago
I know this is not you making this claim, but this type of thinking is what led both the CDC and WHO to mislead the public I'm masks for months. Masks clearly work, but not perfectly. Better masks work better. Wear one if you want to reduce your risk and risk to those around you. We knew this prior to this pandemic. Governments and doctors should stop being so paternalistic and just tell the truth.
- gridlockd 6y ago
  We still do not know that cloth masks work, especially not since before the pandemic, otherwise the WHO and CDC would have recommended them. We especially do not know whether cloth masks reduce personal risk. None of the links given in this overly assertive article show that cloth masks work or that they reduce viral load. All of these are plausible hypotheses and beliefs, but they are still not backed by high quality data.
waterheater 6y ago
I'm also going to use this post to highlight how historical revisionism and censorship of opposing viewpoints is occurring regarding masking. http://web.archive.org/web/20200625094522/https://www.oralhealthgroup.com/features/face-masks-dont-work-revealing-review/ http://web.archive.org/web/20200625094522/https://www.oralhe... The article is called "Why Face Masks Don’t Work: A Revealing Review", published October 18, 2016. This is the webpage as of early July 2020: https://www.oralhealthgroup.com/features/face-masks-dont-work-revealing-review/ https://www.oralhealthgroup.com/features/face-masks-dont-wor... "If you are looking for “Why Face Masks Don’t Work: A Revealing Review” by John Hardie, BDS, MSc, PhD, FRCDC, it has been removed. The content was published in 2016 and is no longer relevant in our current climate." "No longer relevant in our current climate."
- dandelany 6y ago
  The original paper was asking the question: Do surgical masks provide adequate protection against disease transmission for dentists and patients in a clinical context? And their conclusion was: no. This is an entirely separate question from: Do masks provide enough protection against disease transmission to be worth wearing/recommending in public places during a global pandemic, despite their imperfections? The answer to that, from many other studies, seems to be clearly yes. I can imagine that anti-mask folks started using this article as ammunition, due to the catchy headline ("see, this article says face masks don't work!"), and the publishers felt it was doing more harm than good and took it down for that reason.
  - waterheater 6y ago
    >the publishers felt it was doing more harm than good and took it down for that reason. Then the publishers should come out and say so by putting a tagline or disclaimer at the top of the article. Pulling the whole article to "supervise[] conduct and morals" [1] is textbook censorship. [1] https://www.merriam-webster.com/dictionary/censoring https://www.merriam-webster.com/dictionary/censoring
    - dandelany 6y ago
voces 6y ago
> wearing these face masks may produce a false sense of protection However, it is important to note that seat belts from ropes, seat belts from cotton strings, and seat belts from elastic bands offer very little protection when compared to a properly tested and fitted seat belt, and wearing these seat belts may produce a false sense of protection (resulting in no avoidance of speeding or driving too closely to the person in front of you, the best general public guidance we currently have to avoid corporal damage from car crashes).

ketamine__ 6y ago

This randomized trial from 2015 looked at cloth masks. https://bmjopen.bmj.com/content/5/4/e006577 https://bmjopen.bmj.com/content/5/4/e006577 > Conclusions 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. Further research is needed to inform the widespread use of cloth masks globally. However, as a precautionary measure, cloth masks should not be recommended for HCWs, particularly in high-risk situations, and guidelines need to be updated.

GaryNumanVevo 6y ago
Important to note: This study was conducted for _health care workers_. Not the general public. Cloth masks aren't designed to protect the wearer, rather protect everyone else around them by catching droplets / reducing nasal spray / etc. It only works if everyone 95% of people are wearing one, especially indoors.
- ketamine__ 6y ago
  > It only works if everyone 95% of people are wearing one, especially indoors. If this is the only RCT for cloth masks what kind of evidence is behind your claim? Do you have a source?
- jlmorton 6y ago
  The linked article is making an assertion that cloth masks protect the wearer by reducing the viral dose, leading to many more asymptomatic cases. It is saying that mask wearing alone is enough to reduce your risk from coronavirus. That is actually the headline from the article: "Cloth masks do protect the wearer – breathing in less coronavirus means you get less sick"
- misanthropian00 6y ago
  There is no evidence that cloth masks are better at filtering out than they are at filtering in. They are not designed to be one way valves. They are pretty bad at both due to the massive amount of space between threads which virus droplets can just sail right through. No one should be wearing cloth masks if surgical masks are available and no one should be wearing surgical masks when N95 or equiv masks are available. This cannot be repeated enough.

mchusma 6y ago

I know this is not you making this claim, but this type of thinking is what led both the CDC and WHO to mislead the public I'm masks for months. Masks clearly work, but not perfectly. Better masks work better. Wear one if you want to reduce your risk and risk to those around you. We knew this prior to this pandemic. Governments and doctors should stop being so paternalistic and just tell the truth.

gridlockd 6y ago
We still do not know that cloth masks work, especially not since before the pandemic, otherwise the WHO and CDC would have recommended them. We especially do not know whether cloth masks reduce personal risk. None of the links given in this overly assertive article show that cloth masks work or that they reduce viral load. All of these are plausible hypotheses and beliefs, but they are still not backed by high quality data.

waterheater 6y ago

I'm also going to use this post to highlight how historical revisionism and censorship of opposing viewpoints is occurring regarding masking. http://web.archive.org/web/20200625094522/https://www.oralhealthgroup.com/features/face-masks-dont-work-revealing-review/ http://web.archive.org/web/20200625094522/https://www.oralhe... The article is called "Why Face Masks Don’t Work: A Revealing Review", published October 18, 2016. This is the webpage as of early July 2020: https://www.oralhealthgroup.com/features/face-masks-dont-work-revealing-review/ https://www.oralhealthgroup.com/features/face-masks-dont-wor... "If you are looking for “Why Face Masks Don’t Work: A Revealing Review” by John Hardie, BDS, MSc, PhD, FRCDC, it has been removed. The content was published in 2016 and is no longer relevant in our current climate." "No longer relevant in our current climate."

dandelany 6y ago
The original paper was asking the question: Do surgical masks provide adequate protection against disease transmission for dentists and patients in a clinical context? And their conclusion was: no. This is an entirely separate question from: Do masks provide enough protection against disease transmission to be worth wearing/recommending in public places during a global pandemic, despite their imperfections? The answer to that, from many other studies, seems to be clearly yes. I can imagine that anti-mask folks started using this article as ammunition, due to the catchy headline ("see, this article says face masks don't work!"), and the publishers felt it was doing more harm than good and took it down for that reason.
- waterheater 6y ago
  >the publishers felt it was doing more harm than good and took it down for that reason. Then the publishers should come out and say so by putting a tagline or disclaimer at the top of the article. Pulling the whole article to "supervise[] conduct and morals" [1] is textbook censorship. [1] https://www.merriam-webster.com/dictionary/censoring https://www.merriam-webster.com/dictionary/censoring
  - dandelany 6y ago

voces 6y ago

> wearing these face masks may produce a false sense of protection However, it is important to note that seat belts from ropes, seat belts from cotton strings, and seat belts from elastic bands offer very little protection when compared to a properly tested and fitted seat belt, and wearing these seat belts may produce a false sense of protection (resulting in no avoidance of speeding or driving too closely to the person in front of you, the best general public guidance we currently have to avoid corporal damage from car crashes).