Thread by @LenCabrera

Wear a mask because
(1) COVID erased years of science & replaced it with "SCIENCE!" (insert @SteveDeaceShow voice)
(2) It shows you care & is cheaper than sending a card to everyone
(3) It's easier to comply with tyrannical government than to fight for liberty
(1/13)

1975: "The wearing of a surgical face mask had no effect upon the overall operating room environmental contamination" (2/13)
pubmed.ncbi.nlm.nih.gov/1157412/

1981: "No masks were worn in one operating theatre for
6 months. There was no increase in the incidence of wound infection." (3/13)
ncbi.nlm.nih.gov/pmc/articles/P…

1989: "No infections were found in any patient, regardless of whether a cap or mask was used" (4/13)
onlinelibrary.wiley.com/doi/abs/10.100…

1991: "It has never been shown that wearing surgical face masks decreases postoperative wound infections." (5/13)
link.springer.com/article/10.100…

2001: "Surgical face masks worn by patients during regional anaesthesia, did not reduce the concentration of airborne bacteria over the operation field in our study. Thus they are dispensable." (6/13)
europepmc.org/article/med/11…

2001: "The evidence for discontinuing the
use of surgical face masks would appear to be
stronger than the evidence available to support their
continued use" (7/13)
journals.sagepub.com/doi/pdf/10.117…

2015: "overall there is a lack of substantial evidence to support claims that facemasks protect either patient or surgeon from infectious contamination." (8/13)
journals.sagepub.com/doi/pdf/10.117…

2020: "We do not recommend requiring the general public who do not have symptoms of COVID... to routinely wear cloth or surgical masks because there is no scientific evidence they are effective in reducing the risk of SARS-CoV-2 transmission" (9/13)
cidrap.umn.edu/news-perspecti…

6/5/2020 WHO Guidance: “There are currently no studies that have evaluated the effectiveness and potential adverse effects of universal or targeted continuous mask use by health workers in preventing transmission of SARS-CoV-2." (10/13)
who.int/publications/i…

6/5/2020 WHO Guidance: “There is limited evidence that wearing a medical mask by healthy individuals in households… or among attendees of mass gatherings may be beneficial as a measure preventing transmission.” (11/13)

6/5/2020 WHO Guidance: "At present, there is no direct evidence (from studies on COVID19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19." (12/13

6/5/2020 WHO Guidance: “At the present time, the widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider.” (13/13)