Wear a mask - it's airborne!
Until ventilation laws are enacted and building owners roll out change to increase fresh air, HEPA/MERV filter stale air and use CO2 monitors to gauge proximate transmission risks, your only way to be confident about protecting yourself inside shard-air spaces is to wear a mask. We realize that most people in 2024 are not wearing masks for protection at all. Understand that a few people still are, and that they ignore the comments they get.
There were lies about masks and respirators from the start of the pandemic. Ignore them, all masks work, but they vary from 10% protective up to 99.9%. Here’s the definitive study: Masks and respirators for prevention of respiratory infections: a state of the science review - Greenhalgh et al, 2024.
- If you are in a country that has some circulation of Covid-19, maybe wear a mask when mixing with others in enclosed spaces, whether you or others are vaccinated or not.
- We’re long past the era where simple cloth masks are good enough.
- If you can afford N95, FFP2, KF94 respirators then consider having those. If you’re careful taking them off and putting them on, each can last many tens of hours.
N95, FFP2, KF94, KN95 and CN95
If you can afford it, get N95/KF94 grade masks (that are not cloth or washable) for use when mixing with other in public. Citizen Scientist, Aaron Collins, reviews masks for filtration effectiveness and talks about KF94 masks quite a bit, but there are many standards now.
From the fall of 2020 onwards, Aaron Collins with the equipment he had at his home tests high-filtration masks he’s acquired for filtration and leakage. One of the stars of “masks for all” in the pandemic.
We have known since the start that masks would help slow or stop even the pandemic
Articles in the pandemic supporting masks utilization:
- March 25, 2020; Goddard’s Journal video: first review of mask studies over the years and that they work
- May, 2020: University of Chicago and Argonne National Labs (USA): Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks - Konda et al.
- October 15, 2020; Goddard’s Journal video: second review of mask studies over the years and that they work
- Since March 2020; damerousky.cz: Citizen made portal for making masks, started in the Czech Republic (Europe) and now an international multi-language effort
- Active since March 2020; Masks4all.co portal has been pushing the “masks for all” message. And a discussion forum on reddit for the same
- Masks do not create a false sense of security, See Twitter thread by Rob Shirkey
- Aug, 2020: Max-Planck Institute (Germany): Aerosol filtration efficiency of household materials for homemade face masks: Influence of material properties, particle size, particle electrical charge, face velocity, and leaks - Drewnick et al.
- August, 2020; Webmd article: Community Use Of Face Masks And COVID-19: Evidence From A Natural Experiment Of State Mandates In The US
- August 26, 2020; Wei Lyu and George L. Wehby study: The Forgotten Science Behind Face Masks
- Nov, 2020: Virginia Tech: Cloth face coverings help protect both wearers and those nearby - Pan, Harb, Leng & Marr.
- December 2020; William G. Lindsley: Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols
- Dec, 2020: University of Wisconsin “fitter” study (see fitters)
- January 26, 2021; Jeremy Howard et al: An evidence review of face masks against COVID-19
- January 27, 2021; Slate e-Zine: Do You Really Need Two Masks Now?
- January 28, 2021; Salon e-Zine: How high-filtration masks — like the KN95, N95 and KN94 — differ
- January 28, 2021; CBC: Why you might want to start wearing better masks — even outdoors
- January 28, 2021; Buzzfeed: What Is Double-Masking? Here’s How It Can Keep You Safer From The Coronavirus
- January 29, 2021; New York Times & Colorado State Mask Study: How to Choose the Best Cloth Face Mask for You
- Feb, 2021: Effectiveness of Mask Wearing to Control Community Spread of SARS-CoV-2 - Brooks & Butler
- March 5, 2021; The Virus Spread Where Restaurants Reopened or Mask Mandates Were Absent
- Apr, 2021;The Impact of Universal Mask Use on SARS-COV-2 in Victoria, Australia on the Epidemic Trajectory of COVID-19
- May, 2021: Cheng, Ma2, Witt, Rapp, Wild, Andreae, Pöschl, and Su: Face masks effectively limit the probability of SARS-CoV-2 transmission
- June 5, 2021; Cheng et al: Face masks effectively limit the probability of SARS-CoV-2 transmission
- June 29, 2021; BBC: Covid: Masks upgrade cuts infection risk
- July 21, 2021; Scott et al: The introduction of a mandatory mask policy was associated with significantly reduced COVID-19 cases in a major metropolitan city
- July 22, 2021; Study reveals mask rule turned Melbourne’s deadly second wave ‘overnight’ Studu itself.
- Aug 6 2021; “Wearing a mask is not a political statement”
- Aug 19, 2021; Study supports widespread use of better masks to curb COVID-19 indoors
Wikipedia Maintains a long page on mask use in the pandemic here
Goddard’s Journal - listing the “masks work” studies
Goddard’s Journal was among the very first to gather the studies that proved masks work. The author did work that many governments did not, disproving the lies told about masks.
Goddard’s first video - March 2020
Timings from start of video:
- @ 1:17 Jefferson et al (2011) https://pubmed.ncbi.nlm.nih.gov/21735402 Of the nine case-control studies cited in Goddard's quotation of Jefferson, seven involved healthcare workers and two involved mask wearing by uninfected members of the public, Wu et al (2004) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3322931 and Lau et al (2004) @ https://pubmed.ncbi.nlm.nih.gov/15200846
- @ 2:01 Jefferson et al (2008) https://pubmed.ncbi.nlm.nih.gov/18042961
- @ 2:29 MacIntyre (2015) https://pubmed.ncbi.nlm.nih.gov/25858901
- @ 4:09 Hui & Chan (2010) https://pubmed.ncbi.nlm.nih.gov/20674795 and Breban et al (2013) https://pubmed.ncbi.nlm.nih.gov/23831141
- @ 4:21 van Doremalen et al https://www.nejm.org/doi/full/10.1056/NEJMc2004973 and Ong et al (2020) https://jamanetwork.com/journals/jama/fullarticle/2762692
- @ 5:26 Tracht et al (2010) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2818714
- @ 6:58 Cui et al (2019) https://pubmed.ncbi.nlm.nih.gov/31499643/.
- @ 8:22 Tracht et al (2012) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3307882
- @ 9:55 Aiello et al (2012) https://pubmed.ncbi.nlm.nih.gov/22295066
- @ 10:36 Suess et al (2012) https://pubmed.ncbi.nlm.nih.gov/22280120
- @ 11:04 Cowling et al (2009) https://pubmed.ncbi.nlm.nih.gov/19652172
- @ 11:32 Larson et al (2010) https://pubmed.ncbi.nlm.nih.gov/20297744
- @ 12:03 Simmerman et al (2011) https://pubmed.ncbi.nlm.nih.gov/21651736
- @ 12:57 Aiello et al (2012) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3266257
- @ 14:11 MacIntyre (2009) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662657
- @ 15:45 Foo et al (2006) https://pubmed.ncbi.nlm.nih.gov/17026695
- @ 17:19 DIY facemask https://youtu.be/Pb59qBUNg1o (video)
- @ 18:34 DIY facemask https://youtu.be/Bs-E_R5WWsY (video)
Goddard’s second video - October 2020
This was a follow up to the first, as noted at the start of the video. Timings from start of video:
- @00:30 Wang et al (2020) https://gh.bmj.com/content/5/5/e002794
- @ 01:42 Chan et al (2020) https://academic.oup.com/cid/article/71/16/2139/5848814
- @ 05:28 Chu et al (2020) https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext
- @ 10:07 Leung et al (2020) https://www.nature.com/articles/s41591-020-0843-2
- @ 12:03 NHK program on airborne transmission https://youtu.be/vBvFkQizTT4
- @ 12:42 Anfinrud et al (2020) https://www.nejm.org/doi/full/10.1056/NEJMc2007800
- @ 14:02 Fears et al (2020) https://wwwnc.cdc.gov/eid/article/26/9/20-1806_article
- @ 14:33 Lednicky et al (2020) https://www.ijidonline.com/article/S1201-9712(20)30739-6/fulltext
- @ 14:55 Bourouiba (2020) https://jamanetwork.com/journals/jama/fullarticle/2763852
- @ 15:05 Verma et al (2020) https://aip.scitation.org/doi/10.1063/5.0016018
- @ 16:46 Fischer et al (2020) https://advances.sciencemag.org/content/6/36/eabd3083
- @ 19:14 N95 mask-valve leakage. Original: Face Shield or Face Mask to Stop the Spread of COVID-19? by Florida Atlantic University (video)
- @ 20:33 Anti-mask misinformation by retired doctor (no link to the original garbage) See also Politfact debunking (video)
- @ 20:42 That misinformation quickly debunked by Prof Jimenez "Vapor goes thru mask, then condenses" (tweet)
- @ 20:49 Swiss-cheese protection model. Original: RETURN TO WORK AMID COVID-19: A Cleveland Clinic Guide
Anti-Masker activities
Anti Masker groups are motivated by politics, hatred of your group/country, bad science, their own bad breath and more. They link to things they claim can prove their case.
Their bogus talking points:
- “just search for it, I don’t have to give you links to studies”
- “masks starve your oxygen” - they do not
- “Country X or state Y doesn’t have masks, and they’re better than your country”. Ask them what they think about Taiwan or South Korea who’ve performed among the best (with masks), and they get all racist or suggest it is faked.
Raina MacIntyre’s work in particular
Study ‘MacIntyre et al, 2015’, figures quite a lot as an anti-masker “truth”. Goddard’s Journal went into this study above. Meanwhile, Raina C MacIntyre is disgusted with mis-representation by anti-masker groups. She has published more in the last eighteen months to further indicate her science that masks actually work and that we should wear them:
- June 24, 2020; Prof Raina MacIntyre in a Guardian article: "People are still kind of stuck in that mindset of hand sanitiser and washing your hands, when actually the message we need to be getting out there is it’s the air you breathe … and you should wear masks"
- May 12, 2021; Prof Raina MacIntyre in a TheConversation article: "in further evidence the droplet theory is false, we showed that even for infections believed to be spread by droplets, a N95 respirator protects better than a surgical mask. In fact airborne precautions are needed for most respiratory infections."
- January 21, 2021; Prof Raina MacIntyre in Croakey Health Media eZine: "The lack of experts on respiratory transmissible infection or aerosol science at the table meant that much of 2020 was spent on promotion of hygiene theatre, actively discouraging mask use and a resulting low awareness among the general public of the importance of ventilation and masks in reducing their personal risk."
- December 20, 2020; Prof Raina MacIntyre in the Sydney Morning Herald: “Mandating masks across greater Sydney will make a difference”
- December 17, 2020; Prof Raina MacIntyre in the Sydney Morning Herald: “Until we address airborne transmission, we fail to address masks and ventilation and keep peddling the myth that washing hands and wiping surfaces is enough. We need universal masking in closed public spaces”
- October 12, 2020; Prof Raina MacIntyre in the Sydney Morning Herald: “Mandating masks in public places would reduce the risk of transmission from asymptomatic or mildly symptomatic people, protect well people, and enable greater freedom of movement.”
- September 29, 2020; Prof Raina MacIntyre in BMJ Opinion: Cloth masks should be washed appropriately everyday.
- July 4, 2020, Prof Raina MacIntyre in the Sydney Morning Herald: “Face masks have not been recommended actively, although would likely help control the epidemic in Victoria. There is increasing evidence that spread of SARS-CoV-2 is as much due to the air we breathe as it is to what we touch or who coughs in our face. This, plus asymptomatic infection, is a reason why physical distancing and masks are a good idea.”
- June 27, 2020, Prof Raina MacIntyre in The Lancet: Physical distancing, face masks, and eye protection for prevention of COVID-19
- April 21, 2021, The Impact of Universal Mask Use on SARS-COV-2 in Victoria, Australia on the Epidemic Trajectory of COVID-19
Pre-pandemic articles suggesting masks in particular would work
- 2008: UK’s Health and Safety Executive identifies surgical masks as protective on some basis. UK’s FFP2 would have been much better, but at least it doesn’t say “masks are bad”. Surfaced at the start of the pandemic by Tom Andrews
Studies about masks and respirators
Studies of the use of masks/respirators, thread 🧵. From https://mastodon.social/@jmcrookston/111689874254752367
1. Systematic and meta-analyses of masks and respirators
This summary should be accurate but double-check yourself. Don’t forget all the limitations of meta-anslyses.
The following studies found a statistically significant difference between the data relating tomMasks/respirators and not. This suggests the result (that masks work in the contexts of these trials) was unlikely to be due to random chance.
- Macintyre 2017
- Offeddu 2017. Concluded N95 or surgicalwere effective against clinical respiratory infection.
- Iannone 2020 -
The followng studes did not find a statistically significant difference between the data relating to masks/respirators and not. All we can say is we cannot rule out random chance for these results. Authors’ comments are noted.
- Smith 2016 - Pooled three trials (Loeb 2009, MacIntyre 2011, MaIcntyre 2013) and found no statistical difference for lab confirmed respiratory infection. Authors noted N95s are better than SM in lab studies.
- Barycka 2020 - meta failed stat but authors noted less illness with N95s.
- Kunstler 2022 - meta N95 vs SM for SARS2. Failed stat but authors noted the direction of effect favoured respirators.
- Chou 2020 -
- Long 2020 -
- Bartoszko & Loeb 2020 - MM vs N95
Barycka. ‘Comparative Effectiveness of N95 Respirators and Surgical/Face Masks in Preventing Airborne Infections in the Era of SARS-CoV2 Pandemic: A Meta-Analysis of Randomized Trials’. PloS One 15, no. 12 (2020): e0242901. https://doi.org/10.1371/journal.pone.0242901.
Kunstler, Breanne, Skye Newton, Hayley Hill, John Ferguson, Phillipa Hore, Brett G. Mitchell, Kathy Dempsey, et al. ‘P2/N95 Respirators & Surgical Masks to Prevent SARS-CoV-2 Infection: Effectiveness & Adverse Effects’. Infection, Disease & Health 27, no. 2 (May 2022): 81–95. https://doi.org/10.1016/j.idh.2022.01.001.
Smith, Jeffrey D., Colin C. MacDougall, Jennie Johnstone, Ray A. Copes, Brian Schwartz, and Gary E. Garber. ‘Effectiveness of N95 Respirators versus Surgical Masks in Protecting Health Care Workers from Acute Respiratory Infection: A Systematic Review and Meta-Analysis’. CMAJ: Canadian Medical Association Journal = Journal de l’Association Medicale Canadienne 188, no. 8 (17 May 2016): 567–74. https://doi.org/10.1503/cmaj.150835.
Chou, Roger, Tracy Dana, Rebecca Jungbauer, Chandler Weeks, and Marian S. McDonagh. ‘Masks for Prevention of Respiratory Virus Infections, Including SARS-CoV-2, in Health Care and Community Settings : A Living Rapid Review’. Annals of Internal Medicine 173, no. 7 (6 October 2020): 542–55. https://doi.org/10.7326/M20-3213.
Bartoszko, Jessica J., Mohammed Abdul Malik Farooqi, Waleed Alhazzani, and Mark Loeb. ‘Medical Masks vs N95 Respirators for Preventing COVID-19 in Healthcare Workers: A Systematic Review and Meta-Analysis of Randomized Trials’. Influenza and Other Respiratory Viruses 14, no. 4 (July 2020): 365–73. https://doi.org/10.1111/irv.12745.
Long, Youlin, Tengyue Hu, Liqin Liu, Rui Chen, Qiong Guo, Liu Yang, Yifan Cheng, Jin Huang, and Liang Du. ‘Effectiveness of N95 Respirators versus Surgical Masks against Influenza: A Systematic Review and Meta-Analysis’. Journal of Evidence-Based Medicine 13, no. 2 (May 2020): 93–101. https://doi.org/10.1111/jebm.12381.
Offeddu, Vittoria, Chee Fu Yung, Mabel Sheau Fong Low, and Clarence C. Tam. ‘Effectiveness of Masks and Respirators Against Respiratory Infections in Healthcare Workers: A Systematic Review and Meta-Analysis’. Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America 65, no. 11 (13 November 2017): 1934–42. https://doi.org/10.1093/cid/cix681.
MacIntyre, Chandini Raina, Abrar Ahmad Chughtai, Bayzidur Rahman, Yang Peng, Yi Zhang, Holly Seale, Xiaoli Wang, and Quanyi Wang. ‘The Efficacy of Medical Masks and Respirators against Respiratory Infection in Healthcare Workers’. Influenza and Other Respiratory Viruses 11, no. 6 (2017): 511–17. https://doi.org/10.1111/irv.12474.
Iannone, Primiano, Greta Castellini, Daniela Coclite, Antonello Napoletano, Alice Josephine Fauci, Laura Iacorossi, Daniela D’Angelo, et al. ‘The Need of Health Policy Perspective to Protect Healthcare Workers during COVID-19 Pandemic. A GRADE Rapid Review on the N95 Respirators Effectiveness’. PloS One 15, no. 6 (2020): e0234025. https://doi.org/10.1371/journal.pone.0234025.
2. Studies (not meta-analyses)
After adjustment for under-testing, mask mandates emerged as highly effective. Community masking saved substantial numbers of lives, and prevented economic costs, during the SARS-CoV-2 pandemic in Ontario, Canada.
https://academic.oup.com/pnasnexus/advance-article/doi/10.1093/pnasnexus/pgae065/7606553
Radonovich, Lewis J., Michael S. Simberkoff, Mary T. Bessesen, Alexandria C. Brown, Derek A. T. Cummings, Charlotte A. Gaydos, Jenna G. Los, et al. ‘N95 Respirators vs Medical Masks for Preventing Influenza Among Health Care Personnel: A Randomized Clinical Trial’. JAMA 322, no. 9 (3 September 2019): 824–33. https://doi.org/10.1001/jama.2019.11645.
3. Narrative reviews
Schünemann, Holger J., Elie A. Akl, Roger Chou, Derek K. Chu, Mark Loeb, Tamara Lotfi, Reem A. Mustafa, et al. ‘Use of Facemasks during the COVID-19 Pandemic’. The Lancet. Respiratory Medicine 8, no. 10 (October 2020): 954–55. https://doi.org/10.1016/S2213-2600(20)30352-0.