Respiratory Source Control Versus Receiver Protection: Impact of Facemask Fit

Mansour, Mohamed Mohsen; Smaldone, Gerald C.

doi:10.1089/jamp.2012.0998

Cited by 23 publications

(34 citation statements)

References 8 publications

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“…Data on the left represents ‘Maximum Exposure’ (Max Ex); the percent of nebulized particles captured on the filter in the receiver manikin when no facepiece is used on the source (Diaz and Smaldone 2010; Mansour and Smaldone 2013) For each facepiece placed on the Source, there was a significant reduction in receiver exposure (RSC). As expected, the most effective RSC facepiece was the N95.…”

Section: Resultsmentioning

confidence: 99%

“…24045) were used for resistance measurements. Attached to the transducer was a catheter inserted into the nostril of the same manikin used in the study conducted by Mansour and Smaldone (2013) [Resusci Anne CPR Manikin head (No. 310200; Laerdal Medical)].…”

Section: Methodsmentioning

confidence: 99%

“…A chamber detailed previously (Diaz and Smaldone 2010; Mansour and Smaldone 2013) was used to simulate ventilation in a hospital room (6 air exchanges h −1 ). Previous studies demonstrated that in this environment, filtration is the dominant mechanism of protection in RSC.…”

Section: Methodsmentioning

confidence: 99%

“…In a previous study, using this chamber and cascade impaction, polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm (Mansour and Smaldone 2013). …”

Section: Methodsmentioning

confidence: 99%

“…Using an in vitro model, described in detail in recent studies (Diaz and Smaldone 2010; Mansour and Smaldone 2013), we compared the degree of exposure to a receiver from a potentially infected source with and without face masks composed of different materials including a new prototype face mask with lower airflow resistance. Our ultimate goal is a face mask that can be well tolerated by an infected source and provide significant receiver exposure reduction.…”

Section: Introductionmentioning

confidence: 99%

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Respiratory Source Control Using Surgical Masks With Nanofiber Media

2014

The Annals of Occupational Hygiene

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Background: Potentially infected individuals (‘source’) are sometimes encouraged to use face masks to reduce exposure of their infectious aerosols to others (‘receiver’). To improve compliance with Respiratory Source Control via face mask and therefore reduce receiver exposure, a mask should be comfortable and effective. We tested a novel face mask designed to improve breathability and filtration using nanofiber filtration.Methods: Using radiolabeled test aerosols and a calibrated exposure chamber simulating source to receiver interaction, facepiece function was measured with a life-like ventilated manikin model. Measurements included mask airflow resistance (pressure difference during breathing), filtration, (mask capture of exhaled radiolabeled test aerosols), and exposure (the transfer of ‘infectious’ aerosols from the ‘source’ to a ‘receiver’). Polydisperse aerosols were measured at the source with a mass median aerodynamic diameter of 0.95 µm. Approximately 90% of the particles were <2.0 µm. Tested facepieces included nanofiber prototype surgical masks, conventional surgical masks, and for comparison, an N95-class filtering facepiece respirator (commonly known as an ‘N95 respirator’). Airflow through and around conventional surgical face mask and nanofiber prototype face mask was visualized using Schlieren optical imaging.Results: Airflow resistance [ΔP, cmH2O] across sealed surgical masks (means: 0.1865 and 0.1791 cmH2O) approached that of the N95 (mean: 0.2664 cmH2O). The airflow resistance across the nanofiber face mask whether sealed or not sealed (0.0504 and 0.0311 cmH2O) was significantly reduced in comparison. In addition, ‘infected’ source airflow filtration and receiver exposure levels for nanofiber face masks placed on the source were comparable to that achieved with N95 placed on the source; 98.98% versus 82.68% and 0.0194 versus 0.0557, respectively. Compared to deflection within and around the conventional face masks, Schlieren optical imaging demonstrated enhanced airflow through the nanofiber mask.Conclusions: Substituting nanofiber for conventional filter media significantly reduced face mask airflow resistance directing more airflow through the face mask resulting in enhanced filtration. Respiratory source control efficacy similar to that achieved through the use of an N95 respirator worn by the source and decreased airflow resistance using nanofiber masks may improve compliance and reduce receiver exposure.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Respiratory Source Control Using Surgical Masks With Nanofiber Media

2014

The Annals of Occupational Hygiene

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Face masks and respirators: Towards sustainable materials and technologies to overcome the shortcomings and challenges

et al. 2022

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The unprecedented threat of COVID‐19 and the likelihood of other emerging infectious diseases have accentuated the need for sustainable and effective masks and respirators (MAR). MAR assists in minimizing the risk of infection and controlling the spread of pathogens. However, during the COVID‐19 pandemic, there was a worldwide scarcity of MAR due to unprecedented global demand. There are also notable limitations in commonly used MAR, such as low filtration efficiency, poor fit, non‐reusability, physiological impact, lack of biocompatibility and non‐biodegradability, and inability to kill pathogens. Therefore, there remains an unmet need for a comprehensive study focusing on potential materials and new technologies for MAR. Here we outline a comprehensive overview of the limitations of conventional MAR followed by required potential solutions (such as using nanofibers/graphene base filters/metal‐organic framework as filter media, laser scanning and 3D printing for fit and seal, applying antimicrobial nanomaterials coating on filter media, using reusable and biodegradable materials, developing high‐performing cloth masks, improving hydrophobicity, etc.). The information on potential materials and new technologies of MAR and research evidence outlined here can inform further research and development of high‐performing and sustainable respiratory protection technologies to improve the health and safety of the first responders and the community.

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Front lines of the COVID-19 pandemic: what is the effectiveness of using personal protective equipment in health service environments?—a systematic review

Araújo

Filho

Gonçalves

et al. 2021

Int Arch Occup Environ Health

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Purpose This systematic review aimed to evaluate the effectiveness of the use of personal protective equipment (PPE) in closed environments, similar to waiting or exam rooms of healthcare facilities, in the face of exposure to a bioaerosol. Methods Combinations of words were selected for six electronic databases and for the gray literature. To consider the eligibility of the studies to be included/excluded, the acronym “PECOS” was used: humans and/or experimental models that simulate aerosol (Population); aerosol exposure and the use of masks/respirators (exposition/intervention); controlled or not controlled (comparison); effectiveness of PPE and the receiver exposure (outcomes); and randomized clinical studies or not, observational or laboratory simulation studies (Studies design). Results A total of 4820 references were retrieved by the search strategy. Thirty-five articles were selected for complete reading, of which 13 articles were included for qualitative synthesis. A surgical mask or N95 respirator reduced the risk of transmission, even over short distances. The use of masks, even those with less filtering power, when used by all individuals in the same environment is more effective in reducing risk than the use of respirators with high filtering power for only some of the individuals present. Conclusion The use of mask in closed environments is effective in reducing the risk of transmission and contagion of a contaminated bioaerosol, with greater effectiveness when these devices are used by the source and receiver, regardless of the equipment’s filtering power. (PROSPERO 2020 CRD 42020183759). Supplementary Information The online version contains supplementary material available at 10.1007/s00420-021-01775-y.

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Respiratory Source Control Versus Receiver Protection: Impact of Facemask Fit

Cited by 23 publications

References 8 publications

Respiratory Source Control Using Surgical Masks With Nanofiber Media

Respiratory Source Control Using Surgical Masks With Nanofiber Media

Face masks and respirators: Towards sustainable materials and technologies to overcome the shortcomings and challenges

Front lines of the COVID-19 pandemic: what is the effectiveness of using personal protective equipment in health service environments?—a systematic review

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