key: cord-0854727-x6jek9u0
authors: Sunjaya, Anthony P.; Jenkins, Christine
title: Universal face masking in community: Material, design, and considerations—reply
date: 2020-07-06
journal: Respirology
DOI: 10.1111/resp.13905
sha: b04fdba391e08c43f80b5ba250ec59d45c320a21
doc_id: 854727
cord_uid: x6jek9u0

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From the Authors:

We thank Drs Sousa-Pinto et al. 1 for their research efforts addressing the limited evidence currently available on the differing effectiveness of homemade cloth mask materials. We agree with the authors' statement that the materials used are critical determinants of mask effectiveness as shown in the several studies we have also included. We also applaud their focus on affordable materials that can be readily accessed in low-income settings.

The results of their study show better filtration properties for non-woven and two-layered jersey for larger size particles (3 and 5 μm) and cotton plain weave for smaller sized ones (0.5, 0.7 and 1 μm), supporting the results of a recent laboratory study by Konda et al. 2 However, the results showing that polyester was ineffective in filtering smaller sized particles seem to contradict the results of the same author which showed an effectiveness 67-83%. 2 We would also like to bring attention to the importance of fit in the evaluation of these materials as poor fit can have substantial impacts on the material's performance in practice. 3 We appreciate the comments by Drs Liu et al. 4 on the potential properties of an ideal cloth mask and precautions for wearers which support the need for further research on mask materials, design and wear. This may differ between countries based on the availability of materials, facial structure and level of health literacy. Thus, we also support the authors' proposal that national authorities for occupational health could develop standards to be met to ensure safety and efficacy by locally manufactured cloth masks, and agree that the support of health authorities for mask wear in public will be important as lockdown restrictions are relaxed.

While laboratory studies such as the one reported by Drs Sousa-Pinto et al. make an invaluable contribution to our understanding of the factors contributing to mask effectiveness, we urgently need studies evaluating mask effectiveness in real-world settings such as the current pandemic. We believe that the behavioural aspects of mask wearing by the public and the public health recommendations to support it are essential components of success when added to the use of effective materials with known filtration capacity. We urgently need this research to inform public policy to reduce the spread of respiratory viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Only then can the current controversy on recommending face masking in public be resolved.

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Assessment of fabric masks as alternatives to standard surgical masks in terms of particle filtration efficiency

Universal public mask wear during COVID-19 pandemic rationale, design, and acceptability