by Jon Sanders
Director of the Center for Food, Power, and Life, Research Editor | John Locke Foundation
On the second day of mask mess, we got these:
Mask use during COVID-19: A risk adjusted strategy. Environ Pollut. (2020). 266(Pt 1):115099.
Received May 6, 2020, this study examines studies over the use of medical masks, surgical masks, and respirators, not cloth or homemade masks. Regarding the “effectiveness” of those masks, it argues from the basis of several studies that “wearing a [medical or surgical] mask [or respirator] is an effective means of preventing respiratory infectious diseases, which could reduce the risk of infection.” It also cites them as “a low-cost intervention” and “a means of raising public awareness of other NPIs [non-pharmaceutical interventions].”
Regarding the “necessity” of wearing those masks, not homemade masks, the study argues from an assumption of necessity undercut by its conclusion that “these evidences implied that wearing masks would be able to reduce the burden of infectious diseases.”
A problem for Wang et al. is the culture in the “many western advanced economies” as opposed to “Asian countries.” In Asian countries, “wearing masks has become pervasive.” Not so in the West, where “many still may view personal protective equipment (PPE) and physical barrier including wearing the mask as contrary to freedom and individualism.”
Wang et al., however, do not propose “requiring the general public to wear masks.” They propose instead that “Rational guidance should be provided concerning the use of masks.” This rational guidance is how to inform the public about wearing masks and adopting (voluntarily) other measures, including “hand hygiene, ventilation improvement, reduction of gatherings, and social and physical distancing.”
Like Chu et al., it concerns medical masks, surgical masks, and respirators, not the face coverings that Cooper ordered for the general public. Probable effects (“could” reduce, “implied” it “would be able to” reduce, etc.) are insufficient for extreme emergency orders.
Furthermore, Wang et al. specifically propose that policymakers provide “rational guidance” to the public regarding mask wearing and other measures so they would adopt them voluntarily — which is different from leveling extreme emergency orders.
Also, changing the culture is no business of an extreme emergency order.
Facemasks and similar barriers to prevent respiratory illness such as COVID-19: A rapid systematic review. medRxiv (2020).
Posted on April 6, 2020, this study reviewed 31 studies on face mask use, most if not all “about use of medical grade (surgical paper masks).” Those are, after all, what are used by “habitual facemask users, usually in Far East countries” and supported by “street scene photography of Hong Kong, Korean, Chinese, and Japanese cities where facemask wearing is common.”
The studies featuring RCTs found that “wearing a facemask may very slightly reduce the odds of developing ILI [influenza-like illness]/respiratory symptoms,” for which there was only “low-certainty evidence.” The study also featured observational studies, the results of which seemed slightly more effective, but there was still only “low certainty evidence” of a “very small” protective effect if masks are worn by the well, and “very low-certainty evidence” of a “very small” protective effect if masks are worn by the sick. Worn by both sick and well, odds were “modestly reduced,” but again, there was only “low certainty evidence” of that. Also note, these were in households, not community settings.
Brainard et al. expected “RCTs to under-estimate the protective effect [of wearing surgical-grade masks] and observational studies to exaggerate it.”
Their key conclusion, ignored by the Cooper administration’s summary, is this: “The evidence is not sufficiently strong to support widespread use of facemasks as a protective measure against COVID-19.” They write (again, remember the study concerns surgical-grade facemasks, not homemade cloth masks as ordered by Cooper):
We do not consider that the balance of evidence across all available studies supports routine and widespread use of facemasks in the community. However, using a mask for short periods of time by particularly vulnerable individuals during transient exposure events may be justified.
Those are important features: short periods, particularly vulnerable individuals, transient exposure events. Brainard et al. cite several studies against long-term wear of masks. They note that “facemasks soon become moist with condensation from wearer’s breath (facilitating microbial ingress and growth)” — i.e., inhaling microscopic bacteria leading to other infections. Also, they find that:
Many barriers exists that can make it difficult for individuals to wear facemasks correctly for hours over a multi-day period, including perceived breathing impairment and other discomforts. Facemasks are perceived to or genuinely do interfere with ordinary physical activities such as heavy exertion, sleep, oral hygiene, and eating. Facemasks can be uncomfortable, hot, cause skin rashes or simply fee anti-social.” (References omitted.)
Brainard et al. outright state that “The evidence is not sufficiently strong to support widespread use of facemasks as a protective measure against COVID-19.”
“Low certainty” to “very low certainty” evidence of “very small” protective effects and “slight” to “modest” reductions is not enough for extreme emergency orders. Also, as with Chu et al. and Wang et al. above, this study does not even consider the cloth and homemade masks Cooper has ordered for the general public.
Furthermore, this study specifically cautions against some aspects of mask-wearing inherent in the extents of Cooper’s order. It warns of breathing impairments and other risks of long-term wear. It explicitly cites the danger of breathing in the microbial growth on masks, especially from becoming moist over time from exhalation (i.e., “collecting droplets”). It also warns of interference with ordinary physical activities including heavy exertion (which would include physical exercise as well as playing sports), which incidentally would quickly soak masks with moisture. Cooper requires people at gyms, fitness centers, etc. to wear masks even while “strenuously exercising.”
Click for more of the Twelve Days of Mask Mess series.