Mask Facts - AAPS | Association of American Physicians and Surgeons

curated by Marilyn M. Singleton, M.D., J.D.

Transmission of SARS-CoV-2

Note: A COVID-19 (SARS-CoV-2) particle is 0.125 micrometers (μm); influenza virus size is 0.08 – 0.12 μm; a human hair is about 150 μm.

*1 nm = 0.001 micron; 1000 nm = 1 micron; Micrometer (μm) is the preferred name for micron (an older term)

1 meter is = 1,000,000,000 nm or 1,000,000 microns

Droplets

Air currents

Objects and surfaces

Filter Efficiency and Fit

*Data from a University of Illinois at Chicago review

https://www.cidrap.umn.edu/news-perspective/2020/04/commentary-masks-all-covid-19-not-based-sound-data

“Masks may confuse that message and give people a false sense of security. If masks had been the solution in Asia, shouldn’t they have stopped the pandemic before it spread elsewhere?”

*The first randomized controlled trial of cloth masks. https://bmjopen.bmj.com/content/5/4/e006577

*A study of 4 patients in South Korea

https://www.acpjournals.org/doi/10.7326/M20-1342

Known patients infected with SARS-CoV-2 wore masks and coughed into a Petrie dish. “Both surgical and cotton masks seem to be ineffective in preventing the dissemination of SARS–CoV-2 from the coughs of patients with COVID-19 to the environment and external mask surface.”

*Singapore Study – Few people used mask correctly

https://www.medpagetoday.com/infectiousdisease/publichealth/86601

Overall, data were collected from 714 men and women. About half the sample were women and all adult ages were represented. Only 90 participants (12.6%, 95% CI 10.3%-15.3%) passed the visual mask fit test. About three-quarters performed strap placement incorrectly, 61% left a “visible gap between the mask and skin,” and about 60% didn’t tighten the nose-clip.

*A 2011 randomized Australian clinical trial of standard medical/surgical masks

https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1750-2659.2011.00198.x?fbclid=IwAR3kRYVYDKb0aR-su9_me9_vY6a8KVR4HZ17J2A_80f_fXUABRQdhQlc8Wo

Medical masks offered no protection at all from influenza.

Conclusions from Organizations

The World Health Organization (WHO):

https://apps.who.int/iris/bitstream/handle/10665/331693/WHO-2019-nCov-IPC_Masks-2020.3-eng.pdf?sequence=1&isAllowed=y

“Advice to decision makers on the use of masks for healthy people in community settings

As described above, the wide use of masks by healthy people in the community setting is not supported by current evidence and carries uncertainties and critical risks.”

“Medical masks should be reserved for health care workers. The use of medical masks in the community may create a false sense of security, with neglect of other essential measures, such as hand hygiene practices and physical distancing, and may lead to touching the face under the masks and under the eyes, result in unnecessary costs, and take masks away from those in health care who need them most, especially when masks are in short supply.” 

“Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.”

WHO acknowledges that most people do not use masks properly.

Dr. Nancy Messonnier, director of the Center for the National Center for Immunization and Respiratory Diseases:

https://www.cdc.gov/media/releases/2020/t0131-2019-novel-coronavirus.html

“We don’t routinely recommend the use of face masks by the public to prevent respiratory illness,” said on January 31. “And we certainly are not recommending that at this time for this new virus.”

The Centers for Disease Control and Prevention (CDC)

https://www.cdc.gov/flu/professionals/infectioncontrol/maskguidance.htm

In March 5, 2019 regarding the flu: “Masks are not usually recommended in non-healthcare settings; however, this guidance provides other strategies for limiting the spread of influenza viruses in the community:

From the New England Journal of Medicine

https://www.nejm.org/doi/full/10.1056/NEJMp2006372

“We know that wearing a mask outside health care facilities offers little, if any, protection from infection. Public health authorities define a significant exposure to Covid-19 as face-to-face contact within 6 feet with a patient with symptomatic Covid-19 that is sustained for at least a few minutes (and some say more than 10 minutes or even 30 minutes). The chance of catching Covid-19 from a passing interaction in a public space is therefore minimal. In many cases, the desire for widespread masking is a reflexive reaction to anxiety over the pandemic.”

Final Thoughts

If you are sick, stay home!

Additional Resource: Healthy People Wearing Masks, Should They or Shouldn’t They? This ER nurse with over two decades of experience took a deep dive into the science to find out: https://jennifermargulis.net/healthy-people-wearing-masks-during-covid19/

https://aapsonline.org/mask-facts/