How well do face masks protect the wearer compared to public perceptions?

Abstract

IntroductionThere is a growing body of evidence to support the wearing of face masks to reduce spread of infectious respiratory pathogens, including SARS-CoV-2. However, the literature exploring the effectiveness of homemade fabric face masks is still in its infancy. Developing an evidence base is an important step to ensure that public policy is evidence based and truly effective.MethodsTwo methodologies were used in this study: quantitative fit testing of various face masks to indicate their effectiveness and a survey of 710 US residents about their perceptions of face mask effectiveness. N95, surgical and two fabric face masks were tested on an individual twenty five times each using a TSI 8038+ machine. Our survey was distributed by Qualtrics XM, asking participants to estimate the effectiveness of N95, surgical and fabric face masks.Results and DiscussionOur results indicate that fabric face masks blocked between 62.6% and 87.1% of fine particles, whereas surgical masks protected against an average of 78.2% of fine particles. N95 masks blocked 99.6% of fine particles. Survey respondents tended to underestimate the effectiveness of masks, especially fabric masks. Together these results suggest that fabric masks may be a useful tool in the battle against the COVID-19 pandemic and that increasing public awareness of the effectiveness of fabric masks may help in this endeavour.

A systematic review of passing fit testing of the masks and respirators used during the COVID-19 pandemic: Part 1-quantitative fit test procedures

“…In the study by Martelly et al, the significant level was not reported; however, due to the considerable difference between the two studied respirators, it could be considered as a statistically significant difference in terms of FF (7.0 vs. 143) [ 129 ]. Whereas, no significant differences were determined between the studied masks or respirators in the six studies [ 32 , 48 , 51 , 63 , 131 , 132 ]. Due to fit test principle called “OSFA” which stands for there is no one size fits all, fit test results would be unpredictable and each subject could fit with a specific brand, model, style, and size.…”

Functional dependence of COVID-19 growth rate on lockdown conditions and rate of vaccination

“…With regard to the efficacy of mask-based protection against infection, the m value depends on the type of mask used. In Germany, until mid-April, simple two-layer thin cotton fabric masks were the most common, with an average of m = 0.63 of particles [18]. Since mid-April a special decree of the Berlin Senate prohibited the use of these masks in transport, food shops and other public facilities.…”