“15 When Iudah faw her,he thought her to be an harlot: becaufe fhe had co=uered her face.” – THE FIRST BOOKE OF MOSES, called GENESIS. CHAP. XXXVIII.

Already in 1981 it became clear that even in the excessively controlled room that is the operating room (eg. over-pressure and increased oxygen), masks aren’t effective against curtailing wound infection or reducing room contamination. Below is an non-exhaustive list, in chronological order, of what the scientists wrote on using masks, since 1975.

Ritter, Merrill A. et al. “The Operating Room Environment as Affected by People and the Surgical Face Mask” Clinical Orthopaedics and Related Research, Vol. 111, 1975. (https://pubmed.ncbi.nlm.nih.gov/1157412/)

“The wearing of a surgical face mask had no effect upon the overall operating room environmental contamination”

Ha’eri, G.B.; Wiley A.M. “The efficacy of standard surgical face masks: an investigation using “tracer particles”.” Clinical Orthopaedics and Related Research, Vol. 148, 1980. (https://europepmc.org/article/med/7379387)

“Particle contamination of the wound was demonstrated in all experients.”

Orr, Neil W. M. “Is a mask necessary in the operating theatre?” Annals of the Royal College of Surgeons of England, Vol. 63, 1981. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2493952/pdf/annrcse01509-0009.pdf)

“The effectiveness of a mask in reducing contamination varies with the mask’s shape, the materials of which it is made, and the way it is worn (10-11). While it has been shown that facial movements behind a mask can increase wound contamination (12), it has not been shown that wearing a mask makes very much difference to the contamination of the theatre environment (13) or that the number of airborne bacteria can in any way be correlated with wound infection (14,15). It would appear that minimum contamination can best be achieved by not wearing a mask at all but operating in silence. Whatever its relation to contamination, bacterial counts, or the dissemination of squames, there is no direct evidence that the wearing of masks reduces wound infection.”

Laslett, Lawrence J.; Sabin, Alisa. “Wearing of Caps and Masks Not Necessary During Cardiac Catheterization” Catheterization and Cardiovascular Diagnosis, Vol. 17, 1989. (https://onlinelibrary.wiley.com/doi/abs/10.1002/ccd.1810170306)

“No infections were found in any patient, regardless of whether a cap or mask was used”

Tunevall, Th. Goran. “Postoperative Wound Infections and Surgical Face Masks: A Controlled Study” World Journal of Surgery, Vol. 15, 1991. (https://link.springer.com/article/10.1007/BF01658736)

“After 1,537 operations performed with face masks, 73 (4.7%) wound infections were recorded and, after 1,551 operations performed without face masks, 55 (3.5%) infections occurred.”

“It has not been possible to demonstrate any advantages for the patient when the surgical team wears face masks. There- fore, the routine use of face masks ought to be reconsidered.”

Skinner, M.W.; Sutton, B.A. “Do Anaesthetists Need to Wear Surgical Masks in the Operating Theatre? A Literature Review with Evidence- Based Recommendations” Anaesthesia and Intensive Care, Vol. 29, 2001. (https://journals.sagepub.com/doi/pdf/10.1177/0310057X0102900402)

“The evidence for discontinuing the use of surgical face masks would appear to be stronger than the evidence available to support their continued use.”

“There is little evidence to suggest that the wearing of surgical face masks by staff in the operating theatre decreases postoperative wound infections.”

“there is evidence indicating a significant reduction in post- operative wound infection rates when theatre staff are unmasked.”

Figueiredo, Ana E. et al. “Bag Exchange in Continuous Ambulatory Peritoneal Dialysis Without Use of a Face Mask: Experience of Five Years” Renal Unit, Hospital São Lucas, 2001. (http://www.advancesinpd.com/adv01/21Figueiredo.htm)

“Peritonitis rates reported during our observation period are compatible with those seen in other centers (2,3) and support the hypothesis that routine use of a face mask during CAPD bag exchange may be unnecessary.”

Lahme, T. et al. “Patient surgical masks during regional anesthesia. Hygenic necessity or dispensable ritual?” Der Anaesthesist, Vol. 50, 2001. (https://europepmc.org/article/med/11760479)

“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.”

Sjøl, Anette; Kelbaek, Henning. “Is use of surgical caps and masks obsolete during percutaneous heart catheterization?” 2002. (https://europepmc.org/article/med/11924291)

“The routine use of caps and masks does not seem to have that much beneficial impact on the occurrence of procedure-related inflammations or infections in the cardiac catheterisation laboratory.”

Bahli, Zahid Mehmood. “Does Evidence Based Medicine Support The Effectiveness Of Surgical Facemasks In Preventing Postoperative Wound Infections In Elective Surgery?” Journal of Ayub Medical College, 2009. (https://pdfs.semanticscholar.org/751a/cd427c20c8dc7d1fbc1b45eead104286f481.pdf)

“Results: No significance difference in the incidence of postoperative wound infection was observed between masks group and groups operated with no masks (1.34, 95% CI, 0.58–3.07). There was no increase in infection rate in 1980 when masks were discarded. In fact there was significant decrease in infection rate (p<0.05). Conclusion: From the limited randomized trials it is still not clear that whether wearing surgical face masks harms or benefit the patients undergoing elective surgery.”

Sellden, Eva. “Is Routine Use of a Face Mask Necessary in the Operating Room?” Anesthesiology, Vol. 113, 2010. (https://anesthesiology.pubs.asahq.org/article.aspx?articleid=2085803)

“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,”

Webster, Joan et al. “Use of face masks by non-scrubbed operating room staff: a randomized controlled trial” ANZ Journal of Surgery, Vol. 80, 2010. (https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1445-2197.2009.05200.x)

“Surgical site infection rates did not increase when non-scrubbed operating room personnel did not wear a face mask.”

Lipp, Allyson; Edwards, Peggy. “Disposable surgical face masks for preventing surgical wound infection in clean surgery” The Cochrane Library, Issue 2, 2014. (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002929.pub2/full)

“There was no statistically significant difference in infection rates between the masked and unmasked group in any of the trials”

Carøe, T. “Tvivlsom effekt af mundbind under operation” Ugeskrift for Laeger, Vol. 176(27), 2014. (https://ugeskriftet.dk/videnskab/V09130564) [English abstract: https://europepmc.org/article/med/25294675]

“None of the four studies found a difference in the number of post-operative infections whether you used a surgical mask or not.”

Salassa, Tiare E.; Swiontkowski, Marc F. “Surgical Attire and the Operating Room: Role in Infection Prevention” The Journal of Bone and Joint Surgery, Vol. 96, pp. 1485-1492, 2014. (https://journals.lww.com/jbjsjournal/Abstract/2014/09030/Surgical_Attire_and_the_Operating_Room__Role_in.11.aspx)

“Although there is some evidence that scrubs, masks, and head coverings reduce bacterial counts in the operating room, there is no evidence that these measures reduce the prevalence of surgical site infection.”

Da Zhou, Charlie; Sivathondan, Pamela; Handa, Ashok. “Unmasking the surgeons: the evidence base behind the use of facemasks in surgery” Journal of the Royal Society of Medicine, Vol. 108(6), pp. 223-228, 2015. (https://journals.sagepub.com/doi/pdf/10.1177/0141076815583167)

“ overall there is a lack of substantial evidence to support claims that facemasks protect either patient or surgeon from infectious contamination. ”

Vincent, M.; Edwards, P. “Disposable surgical face masks for preventing surgical wound infection in clean surgery” Cochrane Database of Systematic Reviews, Issue 4, 2016. (https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD002929.pub3/full)

“There was no statistically significant difference in infection rates between the masked and unmasked group in any of the trials”

World Health Organization. “Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza” 2019. https://apps.who.int/iris/bitstream/handle/10665/329438/9789241516839-eng.pdf

“there is no evidence that this is effective in reducing transmission”

Further Reading

Masks Don’t Work: https://www.modernsamurai.info/mdw/