Mask Research and Information

PN95 Website Visual - Mask Research

Project N95 is dedicated to providing research and resources regarding the COVID-19 pandemic. A crucial factor in our protection against COVID-19 is the use of masks. Currently, there is a variety of information surrounding masking with new research being published constantly. Below, you will find a plethora of different research articles regarding masks and their efficacy.

Learn More About Mask Research

See these helpful resources for more information and guides to find additional research, evidence, data, and due-diligence, specificially in supporting the effectiveness of Masking to reduce respiratory transmission of disease and exposure to other airborne contaminants.

  • The Annals of Research Collection of Studies A collection of research studies on the effectiveness of Masking

  • Eric Topol Substacks "Ground Truths" Eric Topol heads up a biomedical institute at Scripps Research and talks with colleagues there frequently, along with many respected leaders in these fields around the world. He is a cardiologist, still practicing, with some expertise in genomics, digital and artificial intelligence.

  • Your Local Epidemiologist Dr. Katelyn Jetelina has a Masters in Public Health and PhD in Epidemiology and Biostatistics. The purpose of this newsletter is "to provide a direct line of 'translated' public health science to the local, national, and international community".

  • "MMWR" Morbidity and Mortality Weekly Report.

  • Mayo Clinic Mask related information from Mayo Clinic.

Pediatrics: School Masking Policies and Secondary SARS-CoV-2 Transmission - Figure 1

School Masking Policies and Secondary SARS-CoV-2 Transmission

Pediatrics - By Angelique E. Boutzoukas, Kanecia O. Zimmerman, Moira Inkelas, M. Alan Brookhart, Daniel K. Benjamin, Sabrina Butteris, Shawn Koval, Gregory P. DeMuri, Vladimir G. Manuel, Michael J. Smith, Kathleen A. McGann, Ibukunoluwa C. Kalu, David J. Weber, Amy Falk, Andi L. Shane, Jennifer E. Schuster, Jennifer L. Goldman, Jesse Hickerson, Vroselyn Benjamin, Laura Edwards, Tyler R. Erickson, Daniel K. Benjamin;

May 20, 2022

DISCUSSION "This study provides estimates of secondary transmission from a multistate, diverse network of K–12 school districts in the fall of 2021. Consistent with earlier data,1–4,7,8 secondary transmission across the entire study cohort was low, with more than 90% of cases identified in school members originating from the community. As more students have returned to in-person instruction, schools have been more constrained in their ability to implement physical distancing. The predominant mitigation strategies have been masking and vaccinations for children 5 years of age and older. Among districts with universal masking policies, secondary transmission was reduced by 72% on unadjusted analysis, comparedwith districts having optional masking policies."

Mask Wearing Study Effectiveness

Effectiveness of Mask Wearing to Control Community Spread of SARS-CoV-2

JAMA Network - By John T. Brooks, MD; Jay C. Butler, MD February 10, 2021

CONCLUSION "Community mask wearing substantially reduces transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2 ways. First, masks prevent infected persons from exposing others to SARS-CoV-2 by blocking exhalation of virus-containing droplets into the air (termed source control). This aspect of mask wearing is especially important because it is estimated that at least 50% or more of transmissions are from persons who never develop symptoms or those who are in the presymptomatic phase of COVID-19 illness.1 In recent laboratory experiments, multilayer cloth masks were more effective than single-layer masks, blocking as much as 50% to 70% of exhaled small droplets and particles.2,3 In some cases, cloth masks have performed similar to surgical or procedure masks for source control. Second, masks protect uninfected wearers. Masks form a barrier to large respiratory droplets that could land on exposed mucous membranes of the eye, nose, and mouth. Masks can also partially filter out small droplets and particles from inhaled air. Multiple layers of fabric and fabrics with higher thread counts improve filtration. However, the observed effectiveness of cloth masks to protect the wearer is lower than their effectiveness for source control,3 and the filtration capacity of cloth masks can be highly dependent on design, fit, and materials used. Standards for cloth masks are needed to help consumers select marketed products."

Impact of Public Mask Wearing

An evidence review of face masks against COVID-19

PNAS - By Jeremy Howarda, Austin Huangc, Zhiyuan Lid, Zeynep Tufekcie, Vladimir Zdimalf,Helene-Mari van der Westhuizeng, Arne von Delfth, Amy Pricej, Lex Fridmank, Lei-Han Tangl,Viola Tangn, Gregory L. Watsono, Christina E. Baxp, Reshama Shaikhq, Frederik Questierr,Danny Hernandezs, Larry F. Chuj, Christina M. Ramirezo, and Anne W. Rimoint January 11, 2021

CONCLUSION "The science around the use of masks by the public to impede COVID-19 transmission is advancing rapidly. In this narrative review, we develop an analytical framework to examine mask usage, synthesizing the relevant literature to inform multiple areas: population impact, transmission characteristics, source control, wearer protection, sociological considerations, and implementation considerations. A primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals. Reducing disease spread requires two things: limiting contacts of infected individuals via physical distancing and other measures and reducing the transmission probability per contact. The preponderance of evidence indicates that mask wearing reduces transmissibility per contact by reducing transmission of infected respiratory particles in both laboratory and clinical contexts. Public mask wearing is most effective at reducing spread of the virus when compliance is high. Given the current shortages of medical masks, we recommend the adoption of public cloth mask wearing, as an effective form of source control, in conjunction with existing hygiene, distancing, and contact tracing strategies. Because many respiratory particles become smaller due to evaporation, we recommend increasing focus on a previously overlooked aspect of mask usage: mask wearing by infectious people (“source control”) with benefits at the population level, rather than only mask wearing by susceptible people, such as health care workers, with focus on individual outcomes. We recommend that public officials and governments strongly encourage the use of widespread face masks in public, including the use of appropriate regulation."

Virus Limited VS Rich

Face masks effectively limit the probability of SARS-CoV-2 transmission

Science - By Yafang Cheng, Nan Ma, Christian Witt, Steffen Rapp, Philipp S. Wild, Meinrat O. Andreae,Ulrich Pöschl, & Hang Su

May 20, 2021


"Airborne transmission by droplets and aerosols is important for the spread of viruses. Face masks are a well-established preventive measure, but their effectiveness for mitigating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is still under debate. We show that variations in mask efficacy can be explained by different regimes of virus abundance and are related to population-average infection probability and reproduction number. For SARS-CoV-2, the viral load of infectious individuals can vary by orders of magnitude. We find that most environments and contacts are under conditions of low virus abundance (virus-limited), where surgical masks are effective at preventing virus spread. More-advanced masks and other protective equipment are required in potentially virus-rich indoor environments, including medical centers and hospitals. Masks are particularly effective in combination with other preventive measures like ventilation and distancing."

Biosafety Cabinet

Effectiveness of Face Masks in Preventing Airborne Transmission of SARS-CoV-2

American Society for Microbiology - By Hiroshi Ueki, Yuri Furusawa, Kiyoko Iwatsuki-Horimoto, Masaki Imai, Hiroki Kabata, Hidekazu Nishimura, & Yoshihiro Kawaoka May 20, 2021

CONCLUSION "Guidelines from the CDC and the WHO recommend the wearing of face masks to prevent the spread of coronavirus (CoV) disease 2019 (COVID-19); however, the protective efficiency of such masks against airborne transmission of infectious severe acute respiratory syndrome CoV-2 (SARS-CoV-2) droplets/aerosols is unknown. Here, we developed an airborne transmission simulator of infectious SARS-CoV-2-containing droplets/aerosols produced by human respiration and coughs and assessed the transmissibility of the infectious droplets/aerosols and the ability of various types of face masks to block the transmission. We found that cotton masks, surgical masks, and N95 masks all have a protective effect with respect to the transmission of infective droplets/aerosols of SARS-CoV-2 and that the protective efficiency was higher when masks were worn by a virus spreader. Importantly, medical masks (surgical masks and even N95 masks) were not able to completely block the transmission of virus droplets/aerosols even when completely sealed. Our data will help medical workers understand the proper use and performance of masks and determine whether they need additional equipment to protect themselves from infected patients."