Why Face Masks Don’t Work: A Revealing Review

Why Face Masks Don’t Work: A Revealing Review
oralhealthgroup.com ^ | October 18, 2016 | John Hardie, BDS, MSc, PhD, FRCDC

Posted on 06/27/2020 8:34:23 AM PDT by ransomnote

Yesterday’s Scientific Dogma is Today’s Discarded Fable

Introduction
The above quotation is ascribed to Justice Archie Campbell author of Canada’s SARS Commission Final Report. 1 It is a stark reminder that scientific knowledge is constantly changing as new discoveries contradict established beliefs. For at least three decades a face mask has been deemed an essential component of the personal protective equipment worn by dental personnel. A current article, “Face Mask Performance: Are You Protected” gives the impression that masks are capable of providing an acceptable level of protection from airborne pathogens. 2 Studies of recent diseases such as Severe Acute Respiratory Syndrome (SARS), Middle Eastern Respiratory Syndrome (MERS) and the Ebola Crisis combined with those of seasonal influenza and drug resistant tuberculosis have promoted a better understanding of how respiratory diseases are transmitted. Concurrently, with this appreciation, there have been a number of clinical investigations into the efficacy of protective devices such as face masks. This article will describe how the findings of such studies lead to a rethinking of the benefits of wearing a mask during the practice of dentistry. It will begin by describing new concepts relating to infection control especially personal protective equipment (PPE).

Trends in Infection Control
For the past three decades there has been minimal opposition to what have become seemingly established and accepted infection control recommendations. In 2009, infection control specialist Dr. D. Diekema questioned the validity of these by asking what actual, front-line hospital-based infection control experiences were available to such authoritative organization as the Centers for Disease Control and Prevention (CDC), the Occupational Safety and Health Association (OSHA) and the National Institute for Occupational Safety and Health (NIOSH). 3 In the same year, while commenting on guidelines for face masks, Dr. M. Rupp of the Society for Healthcare Epidemiology of America noted that some of the practices relating to infection control that have been in place for decades, ”haven’t been subjected to the same strenuous investigation that, for instance, a new medicine might be subjected.” 4 He opined that perhaps it is the relative cheapness and apparent safety of face masks that has prevented them from undergoing the extensive studies that should be required for any quality improvement device. 4 More recently, Dr. R. MacIntyre, a prolific investigator of face masks, has forcefully stated that the historical reliance on theoretical assumptions for recommending PPEs should be replaced by rigorously acquired clinical data. 5 She noted that most studies on face masks have been based on laboratory simulated tests which quite simply have limited clinical applicability as they cannot account for such human factors as compliance, coughing and talking. 5

Covering the nose and mouth for infection control started in the early 1900s when the German physician Carl Flugge discovered that exhaled droplets could transmit tuberculosis. 4 The science regarding the aerosol transmission of infectious diseases has, for years, been based on what is now appreciated to be “very outmoded research and an overly simplistic interpretation of the data.” 6 Modern studies are employing sensitive instruments and interpretative techniques to better understand the size and distribution of potentially infectious aerosol particles. 6 Such knowledge is paramount to appreciating the limitations of face masks. Nevertheless, it is the historical understanding of droplet and airborne transmission that has driven the longstanding and continuing tradition of mask wearing among health professionals. In 2014, the nursing profession was implored to “stop using practice interventions that are based on tradition” but instead adopt protocols that are based on critical evaluations of the available evidence. 7

A December 2015 article in the National Post seems to ascribe to Dr. Gardam, Director of Infection Prevention and Control, Toronto University Health Network the quote, “I need to choose which stupid, arbitrary infection control rules I’m going to push.” 8 In a communication with the author, Dr. Gardam explained that this was not a personal belief but that it did reflect the views of some infection control practitioners. In her 2014 article, “Germs and the Pseudoscience of Quality Improvement”, Dr. K Sibert, an anaesthetist with an interest in infection control, is of the opinion that many infection control rules are indeed arbitrary, not justified by the available evidence or subjected to controlled follow-up studies, but are devised, often under pressure, to give the appearance of doing something. 9

The above illustrate the developing concerns that many infection control measures have been adopted with minimal supporting evidence. To address this fault, the authors of a 2007 New England Journal of Medicine (NEJM) article eloquently argue that all safety and quality improvement recommendations must be subjected to the same rigorous testing as would any new clinical intervention. 10 Dr. R. MacIntyre, a proponent of this trend in infection control, has used her research findings to boldly state that, “it would not seem justifiable to ask healthcare workers to wear surgical masks.” 4 To understand this conclusion it is necessary to appreciate the current concepts relating to airborne transmissions.