A review by Skinner and Sutton in 2001 concluded that “The evidence for discontinuing the use of surgical face masks would appear to be stronger than the evidence available to support their continued use.” https://app.cyberimpact.com/click-tracking?ct=ddlxOXTWWl90EryEqcEKoaL2h-gzSc6NGMnZYisIeb1prfLYB2BA0WFJB1WtM2OHdYEwquDuQxpj6iPyIA-mu_9ONer7__h5aFc1_BuYu0w~ PDF!

Lahme et al., in 2001, wrote that “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.” https://europepmc.org/article/med/11760479

Figueiredo et al., in 2001, reported that in five years of doing peritoneal dialysis without masks, rates of peritonitis in their unit were no different than rates in hospitals where masks were worn. http://www.advancesinpd.com/adv01/21Figueiredo.htm

Bahli did a systematic literature review in 2009 and found that “no significant difference in the incidence of postoperative wound infection was observed between masks groups and groups operated with no masks.” https://www.semanticscholar.org/paper/Does-evidence-based-medicine-support-the-of-in-in-Bahli/751acd427c20c8dc7d1fbc1b45eead104286f481?p2df

Surgeons at the Karolinska Institute in Sweden, recognizing the lack of evidence supporting the use of masks, ceased requiring them in 2010 for anesthesiologists and other non-scrubbed personnel in the operating room. “Our decision to no longer require routine surgical masks for personnel not scrubbed for surgery is a departure from common practice. But the evidence to support this practice does not exist,” wrote Dr. Eva Sellden. https://pubs.asahq.org/anesthesiology/article/113/6/1447/9572/Is-Routine-Use-of-a-Face-Mask-Necessary-in-the

Webster et al., in 2010, reported on obstetric, gynecological, general, orthopaedic, breast and urological surgeries performed on 827 patients. All non-scrubbed staff wore masks in half the surgeries, and none of the non-scrubbed staff wore masks in half the surgeries. Surgical site infections occurred in 11.5% of the Mask group, and in only 9.0% of the No Mask group. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1445-2197.2009.05200.x

Lipp and Edwards reviewed the surgical literature in 2014 and found “no statistically significant difference in infection rates between the masked and unmasked group in any of the trials.” Vincent and Edwards updated this review in 2016 and the conclusion was the same. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002929.pub2/full

Carøe, in a 2014 review based on four studies and 6,006 patients, wrote that “none of the four studies found a difference in the number of post-operative infections whether you used a surgical mask or not.” https://europepmc.org/article/med/25294675

Salassa and Swiontkowski, in 2014, investigated the necessity of scrubs, masks and head coverings in the operating room and concluded that “there is no evidence that these measures reduce the prevalence of surgical site infection.” https://journals.lww.com/jbjsjournal/Abstract/2014/09030/Surgical_Attire_and_the_Operating_Room__Role_in.11.aspx

Da Zhou et al., reviewing the literature in 2015, concluded that “there is a lack of substantial evidence to support claims that facemasks protect either patient or surgeon from infectious contamination.” https://app.cyberimpact.com/click-tracking?ct=8XxKbw1a2tlsGS7OVvC-myVx50CQeX6oobkGLYONaABvQQiClT0d3LXoNrvXbfQhxo4nwt3Q8Et_YSEkxFx275oiqB-rFYJbNJL6Yiv8To4~ PDF!

n Epidemics 2017, a meta-analysis concluded that masks had a non-significant protective effect. In the Annuals of Internal Medicine, April 2020, “neither surgical nor cotton masks effectively filtered SARS-CoV-2 during coughs by affected people.”

https://www.sciencedirect.com/science/article/pii/S1755436516300858

According to a University of New South Wales, the widespread use of masks by healthcare workers may put them at increased risk of respiratory illness and viral infections, and their global use should be discouraged.

https://medicalxpress.com/news/2015-04-masksdangerous-health.html

In the British Medical Journal 2015, “Over three times, the risk of contracting influenza-like illness if a cloth mask is used versus no mask at all.” Contaminated masks and masks holding moisture and pathogen retention can increase the risk of infection.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/

A 2016 study in the Journal of Exposure Science & Environmental Epidemiology found 97% of particles penetrated cloth masks, and 44% of particles penetrated medical masks. They reported that cloth masks are only marginally beneficial in protecting individuals from particles less than 2.5 micrometers.

https://www.nature.com/articles/jes201642

As referenced in the New England Journal of Medicine, the size of Coronavirus particles varied between 0.06 micrometers and 0.14 micrometers.

https://www.nejm.org/doi/full/10.1056/NEJMoa2001017

Cloth and surgical masks do not have a fit test. When worn, gaps around the edges allow small particles to enter the respiratory system. Also, according to the May 2010 edition of PLoS One, lack of eye protection was a primary risk factor of SARS-CoV transmission.

https://pubmed.ncbi.nlm.nih.gov/32310553/

Wearing a mask for seven hours straight may not be safe. Carbon dioxide (CO2) rebreathing has been recognized as a concern in the Ergonomics Journal.

https://pubmed.ncbi.nlm.nih.gov/23514282/

In the Head and Neck Pain Journal, most healthcare workers develop de novo PPE‐associated headaches or exacerbation of their pre‐existing headache disorders.

https://headachejournal.onlinelibrary.wiley.com/doi/full/10.1111/head.13811

The Antimicrobial Resistance & Infection Control Journal demonstrated, “Breathing through N95 mask materials have been shown to impede gaseous exchange and impose an additional workload on the metabolic system of pregnant healthcare workers. The benefits of using an N95 mask to prevent serious emerging infectious diseases should be weighed against potential respiratory consequences associated with extended N95 respirator usage.

https://aricjournal.biomedcentral.com/articles/10.1186/s13756-015-0086-z

Masks also hamper oxygen intake; the body and the immune system require optimal levels of oxygen to feed cells and fight off illness, including Covid19. When studied, surgeons who wore surgical masks had a decrease in blood O2 saturation and an increase in pulse rates of the surgeons after the operations due to surgical mask usage.

http://scielo.isciii.es/pdf/neuro/v19n2/3.pdf

According to the Journal of Biomedicines, our oxygen concentration is closely associated with cell survival and immune functioning, making one more susceptible to illness.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6027519/

https://pubmed.ncbi.nlm.nih.gov/29395560/

https://pubmed.ncbi.nlm.nih.gov/32590322/

https://pubmed.ncbi.nlm.nih.gov/15340662/

https://pubmed.ncbi.nlm.nih.gov/26579222/

https://pubmed.ncbi.nlm.nih.gov/31159777/