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. 2018 Mar;10(3):2059-2069.
doi: 10.21037/jtd.2018.03.103.

Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses

S Steve Zhou  1 , Salimatu Lukula  1 , Cory Chiossone  1 , Raymond W Nims  2 , Donna B Suchmann  1 , M Khalid Ijaz  3   4
Affiliations

Assessment of a respiratory face mask for capturing air pollutants and pathogens including human influenza and rhinoviruses

S Steve Zhou et al. J Thorac Dis. 2018 Mar.

Erratum in

Abstract

Background: Prevention of infection with airborne pathogens and exposure to airborne particulates and aerosols (environmental pollutants and allergens) can be facilitated through use of disposable face masks. The effectiveness of such masks for excluding pathogens and pollutants is dependent on the intrinsic ability of the masks to resist penetration by airborne contaminants. This study evaluated the relative contributions of a mask, valve, and Micro Ventilator on aerosol filtration efficiency of a new N95 respiratory face mask.

Methods: The test mask was challenged, using standardized methods, with influenza A and rhinovirus type 14, bacteriophage ΦΧ174, Staphylococcus aureus (S. aureus), and model pollutants. The statistical significance of results obtained for different challenge microbial agents and for different mask configurations (masks with operational or nonoperational ventilation fans and masks with sealed Smart Valves) was assessed.

Results: The results demonstrate >99.7% efficiency of each test mask configuration for exclusion of influenza A virus, rhinovirus 14, and S. aureus and >99.3% efficiency for paraffin oil and sodium chloride (surrogates for PM2.5). Statistically significant differences in effectiveness of the different mask configurations were not identified. The efficiencies of the masks for excluding smaller-size (i.e., rhinovirus and bacteriophage ΦΧ174) vs. larger-size microbial agents (influenza virus, S. aureus) were not significantly different.

Conclusions: The masks, with or without features intended for enhancing comfort, provide protection against both small- and large-size pathogens. Importantly, the mask appears to be highly efficient for filtration of pathogens, including influenza and rhinoviruses, as well as the fine particulates (PM2.5) present in aerosols that represent a greater challenge for many types of dental and surgical masks. This renders this individual-use N95 respiratory mask an improvement over the former types of masks for protection against a variety of environmental contaminants including PM2.5 and pathogens such as influenza and rhinoviruses.

Keywords: Aerosol filtration; Staphylococcus aureus (S. aureus); airborne pollutants (PM2.5); bacteriophage ΦΧ174; influenza; rhinoviruses.

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Conflict of interest statement

Conflicts of Interest: MK Ijaz is employed by RB, which provided funding for the independent evaluation of the test mask. The other authors have no financial interest in RB or the test mask under investigation. The authors (other than MK Ijaz) declare no financial conflict of interest in this work.

Figures

Figure 1
Figure 1
Schematic representation of the N95 test mask, the features designed to enhance wearer comfort, and the permitted airflows. (A) Airflow through the test mask during an exhalation; (B) detail of Smart Valve (located beneath the ventilator fan) showing the permitted air flow from inside to outside of the mask.
Figure 2
Figure 2
Schematic of the test mask showing the various layers.
Figure 3
Figure 3
Test set up for the influenza A virus and rhinovirus type 14 penetration studies.
See this image and copyright information in PMC

References

    1. World Health Organization. Burden of disease from the joint effects of Household and Ambient Air Pollution for 2012. WHO Technical Report. Available online: http://www.who.int/phe/health_topics/outdoorair/databases/AP_jointeffect...
    1. Pope CA, 3rd, Burnett RT, Thun MJ, et al. Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. JAMA 2002;287:1132-41. 10.1001/jama.287.9.1132 - DOI - PMC - PubMed
    1. Hoek G, Krishnan RM, Beelen R, et al. Long-term air pollution exposure and cardio- respiratory mortality: a review. Environ Health 2013;12:43. 10.1186/1476-069X-12-43 - DOI - PMC - PubMed
    1. Yang G, Wang Y, Zeng Y, et al. Rapid health transition in China, 1990-2010: findings from the Global Burden of Disease Study 2010. Lancet 2013;381:1987-2015. 10.1016/S0140-6736(13)61097-1 - DOI - PMC - PubMed
    1. Rohde RA, Muller RA. Air Pollution in China: Mapping of Concentrations and Sources. PLoS ONE 2015;10:e0135749. 10.1371/journal.pone.0135749 - DOI - PMC - PubMed