Do you mask? Do your Mask!
Since the original PPEfattoincasa: Upcycle and Stay Safe! article, the discussion on the need and merits of wearing face masks really took off. After trying to capture some remarks as updates in the original article, I figured they would be better off in a separate article. This article.
The timing of the original article coincided with the publication of a sharp commentary by Leung et al. at The Lancet.
As the spread of coronavirus disease 2019 (COVID-19) outside China is accelerating, we urge policy makers to reconsider the role of masking.
The authors shared a similar sentiment, when it comes to the necessity to take action with regard to wearing face masks, while still considering the current global supply shortage.
In the following days, it set off numerous discussions on the topic (e.g. [1],[2],[3],[4],[5],[16] in Germany, [6],[7],[8],[9],[10],[11],[12],[13],[14],[15] elsewhere), some of which eventually led to introducing new regulations in some conutries ([5],[16]). Still, it is a divisive topic, and many point to studies questioning the efficacy of masks and in particular of home made face masks, while others argue that wearing any mask is better than no mask at all. As van der Sande et al. put it in 2008:
Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection.
Often brought up into the discussions, an article titled Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic? by Davies et al. from 2013, sought to assess just how ‘likely’ that decrease in exposure can be. The article discusses different materials and their efficacies in comparison to surgical masks and respirators. It provides some interesting insights overall. Two points from the authors’ conclusions stand out:
The median-fit factor of the homemade masks was one-half that of the surgical masks.
This can be addressed to an extent with an improved design, e.g. having a wrap-around design, using flexible plates to get a tighter fit around the nose, using shoe lace to tighten the overall fit as discussed in the original article.
Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask.
Different materials are discussed in the article, which is certainly interesting. The authors note the use of two layers, but no additional filtering layers in between. It is to be expected that there will be some improvement as a result of that and the Table 1 in the article can provide some hints regarding suitable materials. The actual combinations still needs to be evaluated.
While I would often argue that not doing something at all is better than doing it halfway or poorly, in this particular scenario I would go against that argument. The bottomline still stands. Bearing in mind some precautions on the design, material, and correct use of face masks, wearing a mask, any mask, is better than wearing no mask at all under the current circumstances. Even preventing a single transmission for each person wearing a mask can make a big difference down the line.
