PONE-D-24-09859Measuring the fitted filtration efficiency of cloth masks, medical masks and respirators

PLOS ONE

Dear Dr. Clase,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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The work is interested, however, reviewers have given comments for improvement. E.g.  It should be mentioned that FE is based on total measured particle count and size-dependent.

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Please submit your revised manuscript by Jul 15 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

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PLOS ONE

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2. Thank you for stating the following in the Competing Interests section: "Amanda Tomkins is a member of Dr Qiyin Fang’s research group which worked on the silicone mask brace. She is also a member of the cloth mask knowledge exchange, a stakeholder group that includes cloth mask manufacturers and fabric distributors.

Catherine Clase has received consultation, advisory-board membership, honoraria, or research funding  from  the  Ontario  Ministry  of  Health, Sanofi, Pfizer,  Leo  Pharma, Astellas,  Janssen,  Amgen,  Boehringer-Ingelheim,  Baxter and, through LiV Academy, AstraZeneca. In 2018 she co-chaired a KDIGO potassium controversies conference sponsored at arm's length by Fresenius Medical Care, AstraZeneca, Vifor Fresenius Medical Care, Relypsa, Bayer HealthCare and Boehringer Ingelheim. She co-chairs the cloth mask knowledge exchange, a stakeholder group that includes cloth mask manufacturers and fabric distributors. She is editor-in-chief of MaskEvidence.org.

Ken G Drouillard is a member of the WE-SPARK Health Institute, University of Windsor and receives funding from the Natural Sciences and Engineering Research Council of Canada, Environment and Climate Change Canada and Ontario Ministry of Conservation, Environment and Parks. In 2020-2022 he acted as science consultant to the Windsor-Essex Sewing Force, a community group engaged in the design, sewing and donation of cloth masks to healthcare providers and vulnerable populations of Southern Ontario. He is a member of the cloth mask knowledge exchange.

Charles-Francois de Lannoy has received funding from various branches of The Natural Sciences and Engineering Research Council of Canada (NSERC), Ontario Centre of Innovation (OCI), formerly Ontario Centres of Excellence (OCE), Ontario Water Consortium (OWC) formerly Southern Ontario Water Consortium (SOWC), Canada First Research Excellence Fund (CFREF), Ontario Together Fund, and Federal Economic Development Agency for Southern Ontario (FedDev). He is a member of cloth mask knowledge exchange, a stakeholder group that includes cloth mask manufacturers and fabric distributors. 

Darren Lawless co-chairs the cloth mask knowledge exchange, and all authors are members.

Other authors have no additional disclosures.

" 

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: This manuscript excellently explains the experimental conduct by the authors.

I would recommend to accept it in current condition. Just minor revision to english proficiency.

The manuscript is good to accept.

Reviewer #2: Comments to the Author

Measuring the fitted filtration efficiency (FFE) of cloth masks, medical masks, and respirators for small aerosol (0.02 – 1 µm) and effect on FFE by user modifications, over masking etc. The study is quite interesting and explained well. However, the manuscript needs to be revised before consideration. The section-wise comments/suggestions on the article are given below:

Abstract:

Closed room with ambient particles supplemented with salt particles. It would be better if a total fraction of ambient and salt aerosol were given. The FFE need to be written with a standard deviation like FFE ± SD.

Introduction:

The introduction is written shortly and concisely; however, some recent literature was missing in a similar domain, which can also be included in the main manuscript or supplementary file. A few are given below:

• Quantitative performance analysis of respiratory facemasks using atmospheric and laboratory generated aerosols following with gamma sterilization. Aerosol and Air Quality Research, 21(1), 200349.

• Evaluation of filtration effectiveness of various types of facemasks following with different sterilization methods. Journal of Industrial Textiles, 51(2_suppl), 3430S-3465S.

• A detailed investigation of N95 respirator sterilization with dry heat, hydrogen peroxide, and ionizing radiation. Journal of Industrial Textiles, 51(1_suppl), 378S-405S.

Methods:

Page 5: How long does a generated NaCl aerosol drying in a room environment? The room temperature and humidity also play a role. The temperature and humidity may be given in the manuscript.

The particle counts between 2000 to 20,000 in per cm3 or per litter or per m3.

Page 6: The statistical methods section needs to be revised into simple sentences. Entire paragraph is given in one sentence. It is tough to understand.

Results:

Table 1: mean and SD are given as comma-separated; it should be better if it is given FE ± SD.

Supplementary file Fig. 1: A two-layer pleated mask should have pleated counts in each mask type. Levels 1, and 3 and certified masks should have detailed specifications like material density, fibre diameter, nose clip, breathing resistance etc.

Supplementary file page19: Given the well-accepted U-shaped relationship between particle size and filtration with a nadir around 0.3 µm,23 it seems probable that our choice of particle range (0.02 – 1 µm) leads to estimates that are conservative compared with those obtained by testing only smaller particles or including much larger particles. Here the sentence should be modified because many studies have been conducted for particle ranges from 10 nm to 10 µm.

Supplementary file page 22: In the Glass fog rating scale, rating numbers 3 & 5 are blank. Something missing?

Supplementary file page 36: Limitation and area for future research: many works have been already performed for many tabulated points. However, agreed with the authors, many areas need to be further researched.

Discussion:

Page 10: Previous studies of FFE for medical and non-medical masks have been limited by minimal sample size and incomplete description of the mask. Please see each detail given for FE and mask characterization in the study below. Hence the sentence may be modified accordingly.

• Quantitative performance analysis of respiratory facemasks using atmospheric and laboratory generated aerosols following with gamma sterilization. Aerosol and Air Quality Research, 21(1), 200349.

• Evaluation of filtration effectiveness of various types of facemasks following with different sterilization methods. Journal of Industrial Textiles, 51(2_suppl), 3430S-3465S.

• A detailed investigation of N95 respirator sterilization with dry heat, hydrogen peroxide, and ionizing radiation. Journal of Industrial Textiles, 51(1_suppl), 378S-405S.

Page 11: The filtration efficiency should also have a standard deviation in running text, though is given in figures.

Page 11: some comments can be added on the filtration efficiency of various masks without leakage.

Conclusion:

In conclusion,, it should be mentioned that FE is based on total measured particle count and size-dependent.

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Reviewer #1: Yes:  Syed Muhammad Zaigham Abbas Naqvi

Reviewer #2: Yes:  Dr. Amit Kumar

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PONE-D-24-09859R1Measuring the fitted filtration efficiency of cloth masks, medical masks and respiratorsPLOS ONE

Dear Dr. Clase,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

• Please respond to the comments of reviewer 3.

Please submit your revised manuscript by Nov 02 2024 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org . When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file.

Please include the following items when submitting your revised manuscript:

• A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'.
• A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'.
• An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'.

If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter.

If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols . Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols .

We look forward to receiving your revised manuscript.

Kind regards,

Simanta Roy

Academic Editor

PLOS ONE

Journal Requirements:

Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice.

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: I Don't Know

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #3: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #3: Yes

**********

6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1:  The manuscript found to be correct and all the comments have been discussed by authors. Manuscript can ve published in current format.

Reviewer #3:  Measuring the fitted filtration efficiency (FFE) of cloth masks, medical masks, and respirators for small aerosol (0.02 – 1 μm) and effect on FFE by user modifications, over masking etc. The study is relevant and explained well. However, the manuscript needs to be minor revised before consideration. The section-wise

comments/suggestions on the article are given below:

-Introduction are written well. Concise. Added adequate references. However, you can review these articles also. https://doi.org/10.1177/00405175211046056, https://doi.org/10.3390/ijerph19116372

-On Methods section- Procedures, the authors discussed Filtration efficiency testing. However, what the authors did with the cloth masks are not clear and it is hard to understand by checking with the figure S2. It might be easy to follow if they can denote the things in the figure. Which things refers to what?

Rest of the sections, they wrote well and well described.

However, this paper has to go through some minor revisions, such as

- they wrote “There was no association between the facial distances bizygomatic distance and menton-sellion length, measured as if for clothing, with a piece of cord that traversed the bridge of the nose and the tip of the nose, respectively, and the same distance measured with calipers: R2 0.03; p=0.53 and R2 0.09; p=0.27, respectively (S6 Fig).” Here, this is not “p”, this should be written in italic form.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean? ). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy .

Reviewer #1: Yes:  Syed Muhammad Zaigham Abbas Naqvi

Reviewer #3: No

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[NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.]

While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/ . PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org . Please note that Supporting Information files do not need this step.

Measuring the fitted filtration efficiency of cloth masks, medical masks and respirators

PONE-D-24-09859R2

Dear Dr. Clase,

We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements.

Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication.

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Kind regards,

Simanta Roy

Academic Editor

PLOS ONE

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