Benefits and advantages
1) May reduce viral spread from viral shedders. This might be particularly important in the context of asymptomatic and pre-symptomatic people
2) Masks may provide protection in closed spaces, such as public transport
a. Considers protection by face masks against influenza A(H1N1)pdm09 virus on trans-pacific passenger aircraft, in 2009. “Wearing a face mask was a protective factor against influenza infection. We recommend a more comprehensive intervention study to accurately estimate this effect.”
3) Masks may provide some protection at mass gatheringsa. The paper concludes “A modest proportion of attendees of MGs [mass gatherings] use facemask, the practice is more widespread among health care workers. Facemask use seems to be beneficial against certain respiratory infections at MGs but its effectiveness against specific infection remains unproven.”
4) Masks can be effective when used alongside hand hygiene
a) Objective: “To investigate whether hand hygiene and use of facemasks prevents household transmission of influenza.”
b) Conclusion: “Hand hygiene and facemasks seemed to prevent household transmission of influenza virus when implemented within 36 hours of index patient symptom onset. These findings suggest that nonpharmaceutical interventions are important for mitigation of pandemic and interpandemic influenza.”
c) Importantly: “Adherence to interventions varied.”
5) Cloth masks can be made at home at low cost washable and reusable and therefore reduce the demand on the ones needed by healthcare professionals
6) Universal wearing of masks fosters a sense of social solidarity in response to the pandemic
7) Masks were a potential link to lower risk of SARS amongst people without known contact during the SARS epidemic
8) Medical masks and N95 masks can be reused for a few days with steam decontamination between use.
Risks and pitfalls
Masks are not as effective hand-washing
Not as effective as social distancing.
N95 masks are most effective, followed by surgical masks. Homemade masks are least effective
Used/dirty masks not disposed of correctly become a health hazard
Difficult to use for some people to use, such as young children or people with respiratory issues
Self-contamination by touching and reusing contaminated mask
Cloth (homemade) masks can become a breeding ground for pathogens due to irregular washing, moisture retention, and poor filtration
May be used instead of, rather than as well as, hand-washing and social distancing
Mandatory wearing increases demand, stretches supply - particularly for those required by health professionals
Masks must fit correctly to be effective
Masks must be used correctly to be effective
Researchers have found that masks may not be as effective at filtering COVID-19
Masks can instil a false sense of security which could lead to engaging in higher risk behaviours
Low compliance for mask wearing in uninfected close contacts
Masks could create a false sense of security that could end up putting people at greater risk. Even with the mouth and nose fully covered, the virus can still enter through the eyes.
Depending on type of mask used, potential breathing difficulties
Masks associated with increased face-touching
Improper decontamination of medical masks or N95 masks can damage the blocking structure of masks
