Face masks during the COVID-19 pandemic

Sewn multi-layered cloth mask.

During the COVID-19 pandemic, face masks such as surgical masks and cloth masks, have been employed as a public and personal health control measure against the spread of SARS-CoV-2. Their use is primarily intended as source control to limit transmission of the virus to others in community and healthcare settings as well as some degree of personal protection to prevent infection.

The use of face masks or coverings by the general public has been recommended by health officials to minimize the risk of transmissions, with authorities either requiring their use in certain settings, such as on public transport and in shops, or universally in public. Health officials have advised that medical-grade face masks, such as respirators, should be prioritized for use by healthcare workers in view of critical shortages, so they generally first and foremost recommend cloth masks for the general public.[1][2]

Early in the pandemic, public health messaging about masking often offered inconsistent and conflicting statements, often dismissive, which led to public confusion and subsequent scrutiny. The recommendations have changed as the body of scientific knowledge evolved.[3] One early recommendation was that only symptomatic individuals should wear masks, though evidence suggested asymptomatic transmission. This was revised to also include individuals without symptoms. About 95% of the world's population live in countries that recommend or mandate the use of masks in public during the pandemic.[4]

There were shortages of masks, leading to use of uncertified and substandard masks with performance inferior to other types.[5]

Different types of face masks have been recommended throughout the COVID-19 pandemic including:

Transparent face shields, medical goggles, and other types of personal protective equipment (PPE) are sometimes used in conjunction with face masks.

Types of mask

Cloth masks

Cloth face masks.
World Health Organization infographic on how to wear a non-medical fabric mask safely. [6]

A cloth face mask is worn over the mouth and nose and made of commonly available textiles. Masks vary widely in effectiveness, depending on material, fit and seal, number of layers, and other factors. Although they are usually less effective than medical-grade masks, many health authorities recommend their use by the general public when medical-grade masks are in short supply, as a low-cost and reusable option.[7][8] Unlike disposable masks, there are no required standards for cloth masks.[9]

One study gives evidence that an improvised mask was better than nothing, but not as good as soft electret-filter surgical mask, for protecting healthcare workers while simulating treatment of an artificially infected patient.[9] Research on nano-materials found masks that utilized electrostatic and mechanical barriers were more effective at filtering particulates in the critical 100 nm range.[10]

Another study had volunteers wear masks they made themselves, from cotton T-shirts and following the pattern of a standard tie behind the head surgical mask,[11] and found the number of microscopic particles that leaked inside the homemade masks were twice that of commercial masks. The homemade mask also let a median average of three times as many microorganisms be expelled by the wearer. But another study found that masks made of T-shirt fabric could be as protective against virus droplets as medical masks, and as breathable, as long as the masks contained at least two layers of fabric.[12]

A peer-reviewed summary of published literature on the filtration properties of cloth and cloth masks suggested two to four layers of plain-weave cotton or flannel, of at least 100 threads per inch.[13] There is a necessary trade-off: increasing the number of layers increases the filtration of the material but decreases breathability. This makes it harder to wear the mask and also increases the amount of leak around the edge of the mask. A plain-language summary of this work, along with a hand-sewn design, suggestions on materials and layering, and how to put on, take off and clean a cloth mask is available.

There was no research on decontaminating and reusing cloth masks, as of May 2020.[9] The CDC recommends removing a mask by handling only the ear loops or ties, placing it directly in a washing machine, and immediately washing hands in soap and water for at least 20 seconds. Cold water is considered as effective as warm water for decontamination.[14] The CDC also recommends washing hands before putting on the mask, and again immediately after touching it.[15]

There is no information on reusing an interlayer filter, and disposing of it after a single use may be desirable.[9] A narrative review of the literature on filtration properties of cloth and other household materials did not find support for the idea of using a filter. A layer of cloth, if tolerated, was suggested instead,[13] or a pm2.5 filter, as a third layer.[16]

Surgical masks

Surgical mask.
World Health Organization infographic on how to wear a medical mask safely. [6]

A surgical mask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. If worn properly, a surgical mask is meant to help block large-particle droplets, splashes, sprays, or splatter that may contain viruses and bacteria, keeping it from reaching the wearer's mouth and nose. Surgical masks may also help reduce exposure of the wearer's saliva and respiratory secretions to others.[17]

Certified medical masks are made of non-woven material. They are mostly multi-layer. Filters may be made of microfibers with an electrostatic charge; that is, the fibers are electrets. An electret filter increases the chances that smaller particles will veer and hit a fiber, rather than going straight through (electrostatic capture).[18][19][20][better source needed][medical citation needed] While there is some development work on making electret filtering materials that can be washed and reused,[21] current commercially produced electret filters are ruined by many forms of disinfection, including washing with soap and water or alcohol, which destroys the electric charge.[22] During the COVID-19 pandemic, public health authorities issued guidelines on how to save, disinfect and reuse electret-filter masks without damaging the filtration efficiency.[23][22] Standard disposable surgical masks are not designed to be washed.

A surgical mask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes, or certain medical procedures. Surgical masks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the face mask and the face.[17] However, in practice, with respect to some infections like influenza, surgical masks appear as effective as respirators (such as N95 or FFP masks).[24] Surgical masks may be labeled as surgical, isolation, dental, or medical procedure masks.[17] Surgical masks are made of a nonwoven fabric created using a melt blowing process.[25][26]

Surgical masks made to different standards in different parts of the world have different ranges of particles which they filter. For example, the People's Republic of China regulates two types of such masks: single-use medical masks (Chinese standard YY/T 0969) and surgical masks (YY 0469). The latter ones are required to filter bacteria-sized particles (BFE ≄ 95%) and some virus-sized particles (PFE ≄ 30%), while the former ones are required to only filter bacteria-sized particles.[27][28][29]

Filtering facepiece respirators

N95 mask.

An N95 mask is a particulate-filtering facepiece respirator that meets the N95 air filtration rating of the US National Institute for Occupational Safety and Health, meaning that it filters at least 95 percent of airborne particles, while not resistant to oil like the P95. It is the most common particulate-filtering facepiece respirator.[30] It is an example of a mechanical filter respirator, which provides protection against particulates, but not gases or vapors.[31] Like the middle layer of[32] surgical masks, the N95 mask is made of four layers[9] of melt-blown nonwoven polypropylene fabric.[33][34][unreliable medical source?] The corresponding face mask used in the European Union is the FFP2 respirator.[35][36]

Hard electret-filter masks like N95 and FFP masks must fit the face to provide full protection. Untrained users often get a reasonable fit, but fewer than one in four gets a perfect fit. Fit testing is thus standard. A line of petroleum jelly on the edge of the mask[37] has been shown to reduce edge leakage[9] in lab tests using manikins that simulate breathing.[37]

Some N95 series respirators, especially those intended for industrial use, have an exhaust valve to improve comfort, making exhalation easier and reducing leakage on exhalation and steaming-up of glasses. Such respirators are not suitable for source control of respiratory disease, such as COVID-19, when worn by an asymptomatic but possibly infected user.[38]

In the COVID-19 pandemic, there were shortages of filtering facepiece respirators, so that they had to be used for extended periods, and/or disinfected and reused. During the COVID-19 pandemic, public health authorities issued guidelines on how to save, disinfect and reuse masks, as some disinfection methods damaged the filtration efficiency.[23][22] Some hospitals stockpiled used masks as a precaution,[39] and some had to reuse masks.

Face shields and eye protection

A medical worker wearing a face shield adjunct to other personal protective equipment at a COVID-19 testing site.

In a scoping review, Godoy et al. (5 May 2020) stated that face shields are used for barrier protection against splash and splatter contamination, but should not be used as primary protection against respiratory disease transmission due to the lack of a peripheral seal rather than as an adjunct to other facial protection.[9] They remarked that face shields have been used like this alongside medical-grade masks during the COVID-19 pandemic.[9] They cited a cough simulation study by Lindsley et al. (2014) in which face shields were shown to reduce the risk of inhalation exposure up to 95% immediately following aerosol production, but that the protection was decreased with smaller aerosol particles and persistent airborne particles around the sides.[40]

In a systematic review of observational studies on the transmission of coronaviruses, funded by the World Health Organization (WHO), Chu et al. (27 June 2020) found that eye protection including face shields was associated with less infection (adjusted odds ratio 0.22; 95% confidence interval 0·12 to 0·39), but the evidence was rated as low certainty.[41]

The US Centers for Disease Control and Prevention (CDC) does not recommend the use of face shields as a substitute for masks to help slow the spread of COVID-19.[42] In a study by Lindsley et al. (7 January 2021) funded by the National Institute for Occupational Safety and Health, part of the CDC, face shields were found to block very little cough aerosols in contrast to face coverings—such as cloth masks, procedure masks, and N95 respirators—indicating that face shields are not effective as source control devices for small respiratory aerosols and that face coverings are more effective than face shields as source control devices to reduce the community transmission of SARS-CoV-2.[43]

Elastomeric respirators

Elastomeric full facepiece respirator.

Elastomeric respirators are reusable personal protective equipment comprising a tight-fitting half facepiece or full facepiece respirator with exchangeable filters such as cartridge filters.[44] They provide an alternative respiratory protection option to filtering facepiece respirators such as N95 masks for healthcare workers during times of short supply caused by the pandemic, as they can be reused over an extended period in healthcare settings.[44][45] However, elastomeric respirators have a separate exhalation vent that allows unfiltered exhaled air to be released, so the healthcare worker must be attentive that he or she is not infected with SARS-CoV-2 to prevent possible spread of the virus to others.[45]

For the COVID-19 response when supplies are short, the US CDC states that contingency and crisis strategies should be followed: Each elastomeric respirator is issued for the exclusive use of an individual healthcare provider, but must be cleaned and disinfected as often as necessary to remain unsoiled and sanitary. If there is no other option than to share a respirator between healthcare providers, the respirator must be cleaned and disinfected before it is worn by a different individual. Filters (except for unprotected disc types) may be used for an extended period, but the filter housing of cartridge types must be disinfected after each patient interaction.[44]

Powered air-purifying respirators

Powered air-purifying respirators, including a waist pack and hose to blow air into the headpiece.

A powered air-purifying respirator (PAPR) is a personal protective equipment in which a device with a filter and fan creates a highly filtered airflow towards the headpiece and a positive outflow of air from the headpiece.[46]

There is an increased risk for healthcare workers to become exposed to SARS-CoV-2 when they conduct aerosol-generating procedures on COVID-19 patients, which is why it is argued that such situations may require enhanced personal protective equipment (i.e., higher than N95) such as PAPRs for healthcare workers.[46][47]

In a systematic review, Licina, Silvers, and Stuart (8 August 2020) stated that field studies indicate that there was equivalent rates of infection between healthcare workers, who performed airway procedures on critical COVID-19 patients, utilizing PAPRs or other appropriate respiratory equipment (such as N95 or FFP2), but remarked that there is a need to further collect field data about optimal respiratory protection during highly virulent pandemics.[48]

Face masks with exhalation valves

Image
Droplet flow visualizations comparing face mask efficacy with and without exhalation valve published under a free license in November 2020. [49] [50]

After visualizing droplet dispersal for face shields and masks with exhalation valves, scientists reported that these two types of face coverings can be ineffective against COVID-19 spread – e.g. after a cough – and recommended alternatives to minimize viral spread.[51][52]

Recommendations

According to #Masks4All, about 95% of the world population lives in countries where the government and leading disease experts recommends or require the use of masks in public places to limit the spread of COVID-19.[4]

WHO advice

The World Health Organization (WHO) in its updated advice dated 5 June 2020 recommends that the general public should wear non-medical fabric masks where there is known or suspected widespread transmission and where physical distancing is not possible, and that vulnerable people (aged over 60 or with underlying health risks) and people with any symptoms suggestive of COVID-19 as well as caregivers and healthcare workers should wear medical masks (defined as surgical or procedure masks).[2] They stated that the purpose of mask usage is to prevent the wearer transmitting the virus to others (source control) and to offer protection to healthy wearers against infection (prevention).[2]

The WHO advises that non-medical fabric masks should comprise a minimum of three layers,[2] suggesting an inner layer made of absorbent material (such as cotton), a middle layer made of non-woven material (such as polypropylene) which may enhance filtration or retain droplets, and an outer layer made of non-absorbent material (such as polyester or its blends) which may limit external contamination from penetration.[53]

On 21 August 2020, the WHO and UNICEF released an annex guidance for children.[54] For children aged 5 or younger, they advise that masks should not be required in consideration to a child's developmental milestones, compliance challenges, and autonomy required to use a mask properly, but recognized that the evidence supporting their cut-off age is limited and that countries may hold a different and lower age of cut-off.[54] For children between 6 and 11 years of age, they advise that mask usage should be decided in consideration of several factors including the intensity of local viral transmission, (the latest evidence about) the risk of infection for the age group, the social and cultural environment (which influences social interactions in communities and populations), the capacity to comply with appropriate mask usage, the availability of appropriate adult supervision, and the potential impact on learning and psychosocial development, as well as additional factors involving specific settings or circumstances (such as disabilities, underlying diseases, elderly people, sport activities, and schools).[54] For children aged 12 or older, they advise that masks should be worn under the same conditions for adults in accordance to WHO guidance or national guidelines.[54]

Previously, early in the outbreak, the WHO had only recommended medical masks for people with suspected infection and respiratory symptoms, their caregivers and those sharing living space, and healthcare workers.[55][56] In a 6 April advice, the WHO recognized that wearing a medical mask can limit the spread of certain respiratory viral diseases including COVID-19, but believed that the use of a mask alone is not sufficient to provide an adequate level of protection and that other measures (such as hand hygiene) should be adopted.[57] In the scope of the community setting, the WHO stated that medical masks should be reserved for healthcare workers, except for people with symptoms, claiming that medical masks would create a false sense of security and neglect of other measures.[57] The WHO advice for people to wear masks only if they had symptoms was scrutinized, as experts and researchers have pointed out the asymptomatic transmission of the virus.[58][59][60][61][62] The WHO revised its mask guidance in June, with its officials acknowledging that studies have indicated asymptomatic or pre-symptomatic spread but that not much is known.[63]

The WHO had early suggested that mask usage possibly leads to neglect of other essential health measures such as hand hygiene practices, but, according to Marteau et al. (27 July 2020), available evidence does not support that masking adversely affects hand hygiene.[64] Dame Theresa Marteau, one of the researchers, remarked that "The concept of risk compensation, rather than risk compensation itself, seems the greater threat to public health through delaying potentially effective interventions that can help prevent the spread of disease."[65]

Regarding the use of non-medical fabric masks in the general population, the WHO has stated that high-quality evidence for its widespread use is limited, but advises governments to encourage its use as physical distancing may not be possible in some settings, there is some evidence for asymptomatic transmission, and masks could be helpful to provide a barrier to limit the spread of potentially infectious droplets.[66]

US CDC advice

Guidance from the US Centers for Disease Control and Prevention on using and making cloth masks during the COVID-19 pandemic. [67]
The CDC does not recommend masks with exhalation valves or vents for source control. [42] In the healthcare workers guidance, if only respirators with valves are available and source control is needed, the CDC recommends that the valve should be covered with a surgical mask, procedure mask, or cloth face covering. [68]

The United States Centers for Disease Control and Prevention (CDC) since 3 April 2020 recommend that people wear a cloth face covering in public.[69] In its guidance, since 28 June, the "CDC recommends that people wear cloth face coverings in public settings and when around people who don't live in your household, especially when other social distancing measures are difficult to maintain. Cloth face coverings may help prevent people who have COVID-19 from spreading the virus to others. Cloth face coverings are most likely to reduce the spread of COVID-19 when they are widely used by people in public settings."[70]

In a 10 November 2020 scientific brief, the CDC reiterated their recommendation for the community use of masks and specifically non-valved multi-layer cloth masks to prevent transmission of SARS-CoV-2.[71] They state that the community use of masks serves two primary purposes: to reduce the emission of virus-laden droplets from exhalation into the environment (source control), which is especially relevant for asymptomatic or presymptomatic infected wearers who feel well and may be unaware of their infectiousness to others, and to reduce inhalation of these droplets through filtration for the wearer (personal protection).[71] They concluded that the benefit of masking for SARS-CoV-2 control is derived from the combination of source control and personal protection, which is likely complementary and possibly synergistic, so that individual benefit increases with increasing community mask use.[71]

In the guidance, since 28 June, the CDC provides the caveat that cloth face coverings should not be worn by children under the age of two, persons who have trouble breathing, or persons who are unconscious, incapacitated, or otherwise unable to remove the mask without assistance.[70] On 7 August, the CDC added that exhalation valves or vents in masks do not help prevent the person wearing the mask from spreading COVID-19 to others (source control), as the one-way hole in the material may allow expelled respiratory droplets from the exhaled air to reach others.[42][72]

The CDC states that healthcare personnel should wear a NIOSH-approved N95 (or equivalent or higher-level) respirator or a face mask (if a respirator is not available) with a face shield or goggles as part of their personal protective equipment, while patients with suspected or confirmed SARS-CoV-2 infection should wear a face mask or cloth face covering during transport.[73] As crisis strategy for known shortages of N95 respirators in healthcare settings, among other sequential measures, the CDC suggests use of respirators beyond the manufacturer-designated shelf life, use of respirators approved under standards used in other countries that are similar to NIOSH-approved respirators, limited re-use of respirators, use of additional respirators beyond the manufacturer-designated shelf life that have not been evaluated by NIOSH, and prioritizing the use of respirators and face masks by activity type.[74]

Early in the pandemic, the CDC said that it did not recommend the use of face masks for the general public.[75][76] However, on 3 April 2020, the CDC changed its advice to recommend that people wear cloth face coverings "in public settings when around people outside their household, especially when social distancing measures are difficult to maintain."[77] In response to a media inquiry by the NPR, the CDC said that this change in guidelines was due to the increasing and widespread transmission of the virus, citing studies published in February and March showing presymptomatic and asymptomatic transmission.[78] In an interview with 102.3 KRMG on 28 July 2020, the CDC director Robert R. Redfield explained that they assumed that the disease was a symptomatic illness when they originally looked at masks, not understanding at the time how much of the viral infection was asymptomatic or presymptomatic, but came to understand the critical role of face coverings for source control once they understood that.[79]

Larry Gostin, a professor of public health law, said that initial CDC and WHO guidance had given the public the wrong impression that mask do not work, even though scientific evidence to the contrary was already available.[78] The confusing changing advice from discouraging to recommending public masking has led to decreasing public trust in the CDC.[60][80] In June 2020 Anthony Fauci, a leading infectious disease expert for the United States government, admitted that the delay in recommending general mask use was motivated by a desire to conserve dwindling supplies for medical professionals.[81]

In an interview with JAMA on 14 July 2020, Redfield said that "The data is clearly there that masking works. [...] Masking is not a political issue. It is a public health issue. It really is a personal responsibility for all of us."[82] He and two other CDC officials explained in a JAMA editorial, published on the same day, that "Covering mouths and noses with filtering materials serves 2 purposes: personal protection against inhalation of harmful pathogens and particulates, and source control to prevent exposing others to infectious microbes that may be expelled during respiration. When asked to wear face coverings, many people think in terms of personal protection. But face coverings are also widely and routinely used as source control."[83] In regards to the changes in CDC recommendations towards universal masking, they clarified that "Early in the pandemic, the Centers for Disease Control and Prevention (CDC) recommended that anyone symptomatic for suspected coronavirus disease 2019 (COVID-19) should wear a face covering during transport to medical care and prior to isolation to reduce the spread of respiratory droplets. After emerging data documented transmission of SARS-CoV-2 from persons without symptoms, the recommendation was expanded to the general community, with an emphasis on cloth face coverings that could be made more widely available in the community than surgical masks and to preserve personal protective equipment such as N95 respirators to the highest-risk exposures in health care settings. Now, there is ample evidence that persons without symptoms spread infection and may be the critical driver needed to maintain epidemic momentum."[83]

China and Asia

China has specifically recommended the use of disposable medical masks by the public, including its healthy members,[84][85] particularly when coming into close contact (1 metre (3 ft) or less) with other people.[86] Hong Kong recommends wearing a surgical mask when taking public transport or in crowded places.[87][88] Thailand's health officials are encouraging people to make cloth face masks at home and wash them daily.[89] The Republic of China (Taiwan), South Korean, and Japanese governments have also recommended the use of face masks in public.

In March 2020, when asked about the mistakes that other countries were making in the pandemic, the Chinese Center for Disease Control and Prevention director-general George Fu Gao said:

"The big mistake in the U.S. and Europe, in my opinion, is that people aren't wearing masks. This virus is transmitted by droplets and close contact. Droplets play a very important role − you've got to wear a mask, because when you speak, there are always droplets coming out of your mouth. Many people have asymptomatic or presymptomatic infections. If they are wearing face masks, it can prevent droplets that carry the virus from escaping and infecting others."[90]

Europe

Most countries in Europe have introduced mandatory face mask rules for public places.[91][92] On 8 April 2020, the European Centre for Disease Prevention and Control published its masking recommendations, stating that the "use of face masks in the community could be considered, especially when visiting busy, closed spaces".[93][1]

The Nordic countries have been a notable exception to supporting the use of face masks, but most eventually started to recommend masks.[92] The main reasoning against masks recommendations given by officials in the Nordic countries was that public masking is deemed an unnecessary precaution when infection levels remain low.[94] In June 2020, the Norwegian Institute of Public Health said that the wearing of face masks by asymptomatic individuals was not to be recommended due to the low prevalence of COVID-19 in the country, but noted that it should be reconsidered if cases rise.[95] Similarly, on 30 July 2020, the Danish Health Authority director Sþren Brostrþm said that face covers did not make sense in the current situation with low infection levels, but that they needed to evaluate whether it could make sense in the long term.[96][97] From 29 October, face masks are mandatory inside in any building in Denmark that has public access – from supermarkets and kiosks to hospitals and schools.[98] In many Norwegian local municipalities, face masks are mandatory on public transport where a social distance of one metre is impossible to maintain.[99]

The state epidemiologist of Sweden, Anders Tegnell, maintains his position to not recommend use of face masks and deems face masks as a symbolic measure, possibly to be used on local level.[100] Sweden's FolkhÀlsomyndigheten does not recommend the broad societal use of face mask, but notes that face masks should always be seen as complementary to other preventive measures and deems the evidence for societal use of mask as insufficient.[101] At a press conference on 18 December 2020 FolkhÀlsomyndigheten and the Swedish government finally announced that face masks will be recommended, but not mandatory, during rush hour on public transports from 7 January 2021, almost three weeks after the announcement was made.[102] On 20 December 2020, the prime minister of Sweden, Stefan Löfven, was paparazzied in a shopping mall in central Stockholm without wearing a face mask.[103]

Rationale for wearing masks

Schlieren image showing the interaction of exhaled airflows between two persons. [104]

Masks are used to limit the transmission of SARS-CoV-2 by respiratory droplets and aerosols, which are thought to be the major pathways of infection, exhaled from infected individuals during breathing, speaking, coughing, and sneezing.[105][106]

The National Health Commission of China cited the following reasons for the wearing of masks by the public, including healthy individuals:

  1. Asymptomatic transmission. Many people can be infected without symptoms or only with mild symptoms.[107]
  2. Difficulty or impossibility of appropriate social distancing in many public places at all times.[107]
  3. Cost-benefit mismatch. If only infected individuals wear masks, they would possibly have a negative incentive to do so. An infected individual might get nothing positive, but only bear the costs such as inconvenience, purchasing expenses, and even prejudice.[107]
  4. There is no shortage of masks in China. The country has the production capacity to meet the demand on masks.[107]

In a comment to The Lancet, Kar Keung Cheng, Tai Hing Lam, and Chi Chiu Leung argued that a public health rationale for mass masking is source control to protect others from respiratory droplets and underscored the importance of this approach due to asymptomatic transmission.[108] Wang Linfa, an infectious disease expert who heads a joint Duke University and National University of Singapore research team, stated that masking is about "preventing the spread of disease rather than preventing getting the disease", remarking that the point is to cover the faces of people who are infected but do not know it, so it is imperative for everyone to wear one in public.[59] The US CDC also highlighted the use of masks for source control, pointing out that asymptomatic and presymptomatic cases are estimated to account for over 50% of the transmissions.[109]

Yuen Kwok-yung, a microbiologist from the University of Hong Kong, states a high amount of virus strands in saliva of infected people and transmission by asymptomatic carriers as the reasons why even seemingly healthy individuals should wear a mask.[110] Kelvin Kai-Wang To et al. (February 2020) detected live SARS-CoV-2 in the saliva of infected patients, which indicated that the virus may be transmitted directly or indirectly through saliva with or without respiratory symptoms, and stated that the findings reinforced the use of surgical masks as a control measure.[111]

Monica Gandhi, a medical professor at the University of California, San Francisco, states that viral shedding at high quantities from the upper respiratory tract, characterized by unusually high levels of viral particles, means that universal mask wearing is one of the best ways to limit the asymptomatic spread of the virus.[112] Yixuan Hou et al. (July 2020) found that the nasal cavity is seemingly the dominant initial site for SARS-CoV-2 infection with subsequent aspiration-mediated virus seeding into the lungs; the authors note that these findings argue for the widespread use of masks to prevent exposure to the nasal passages.[113]

In a perspective, Monica Gandhi, Chris Beyrer, and Eric Goosby posit that masking reduces the inoculum of the virus for the wearer and thus helps lower the severity of infection.[114] They highlighted that the proportion of asymptomatic and mild infection increased in settings adopting population-level masking.[114] One example involved a comparison of outbreaks on cruise ships: the Diamond Princess had 18% asymptomatic cases among all the infected people, but this was 81% in the Greg Mortimer where masks were given to passengers and staff members.[114]

Trisha Greenhalgh et al. argue for the precautionary principle as a reason to adopt policies encouraging the wearing of face masks in public, given that there's much to gain and little to lose from adopting masks considering the seriousness of the outbreak.[115] Others agreed, based on the evidence-based principle that the likely benefits outweighed the likely harms.[116][117]

Leonardo Setti et al. argue that face masks should be used to complement social distancing of 6 feet or 2 meters, because this inter-personal distance is more effective if people are masked as studies indicate that SARS-CoV-2 could be transmitted over greater distances.[118] Chi Chiu Leung et al. also argue that face masks complement social distancing, as a high degree of compliance for distancing is necessary to achieve the greatest impact but is not always achievable.[119] For instance, even if social distancing is rigorously practiced, there are necessary person-to-person contacts (such as going to the supermarket and other necessary activities to sustain livelihoods), so masks would help in situations when social distancing is not feasible and maximize the effect of social distancing.[119]

According to Stephen Griffin, a virologist at the University of Leeds, "Wearing a mask can reduce the propensity for people to touch their faces, which is a major source of infection without proper hand hygiene."[120] Ka Hung Chan and Kwok-Yung Yuen argue that face masks can reduce fomite transmission (in addition to transmission through droplets or aerosol) of the virus, as masks can prevent people from spreading body fluids by touching their noses or mouths (such as trying to cover up a sneeze or cough).[121]

A paper by Miyu Moriyama et al. (September 2020), which links seasonality of respiratory viral diseases to decreased air humidity due to indoor heating, argues that mask wearing helps limiting respiratory virus transmission in winter, because masks keep the nose warm and moist.[122]

Social media claims that masks could reduce the oxygen levels in older people were refuted by a small study of SpO2 levels, the results of which were published by JAMA.[123]

Efficacy studies for COVID-19

A WHO-funded systematic review by Chu et al. (27 June 2020) published in The Lancet found that the usage of face mask could result in a large risk reduction of infection with epidemic-causative betacoronaviruses, in which N95 or similar respirators accounted for a larger risk reduction than disposable surgical or other similar masks.[41] Masks were found to be protective for both healthcare workers and people in communities exposed to infection; evidence supported masking in both healthcare and non-healthcare settings, with no striking differences detected in the effectiveness of masks between the settings.[41]

A study by Chan et al. (30 May 2020), using SARS-CoV-2-challenged and non-infected Syrian hamsters placed in closed units with unidirectional airflow to test the effect of surgical mask partitions, concluded that SARS-CoV-2 can be transmitted by respiratory droplets or airborne droplet nuclei and that such transmission could be reduced by usage of surgical masks, especially when worn by infected individuals.[124] The results showed that transmission was reduced from 66.7% to 25% and that the exposed hamsters who became infected showed less severe manifestations of the infection than their virus-challenged counterparts as measured by clinical scoring, histopathology, and viral nucleocapsid antigen expression.[124] Yuen Kwok-yung, one of the researchers, said that "The findings implied to the world and the public is that the effectiveness of mask-wearing against the coronavirus pandemic is huge,"[125][126][127] but cautioned that a risk of infection still remains.[125]

A report by Hendrix et al. (17 July 2020) detailed that 139 clients exposed to two symptomatic hair stylists with confirmed COVID-19—with both the clients and stylists wearing face coverings—resulted in no symptomatic cases reported among all clients and no positive tests among the 67 people who volunteered to be tested.[128] This case was highlighted when the CDC reiterated that Americans should wear masks in their 14 July 2020 press release.[129]

The CDC highlighted several studies, including the hair stylists study, in their 10 November 2020 scientific brief detailing the community benefit of masking.[130] In a study of 124 Beijing households with at least one laboratory-confirmed case of SARS-CoV-2 infection, mask use by the index patient and family contacts before the index patient developed symptoms reduced secondary transmission within the households by 79%.[131] A retrospective case-control study from Thailand documented that, among more than 1,000 persons interviewed as part of contact tracing investigations, those who reported having always worn a mask during high-risk exposures experienced a greater than 70% reduced risk of acquiring infection compared with persons who did not wear masks under these circumstances.[132] A study of an outbreak aboard the USS Theodore Roosevelt, an environment notable for congregate living quarters and close working environments, found that use of face coverings on-board was associated with a 70% reduced risk.[133] Investigations involving infected passengers aboard flights longer than 10 hours strongly suggest that masking prevented in-flight transmissions, as demonstrated by the absence of infection developing in other passengers and crew in the 14 days following exposure.[134] In addition, the CDC stated that the benefit of universal masking, including reductions in infections and mortality, has been demonstrated in community-level analyses by a set of studies involving the Massachusetts hospital system, the German city Jena, the American state Arizona, a panel of 15 American states and Washington, D.C., Canada nationally, and the United States nationally.[130]

Optimal face mask designs and use

A scientific review of research about the overall efficacy of face masks in terms of product design aspects – such as thermal comfort and flow resistance – and ways of usage found that fluid dynamics of the face mask filtration performance such as the droplet and aerosol transport material types and fabrication techniques have a significant impact on the performance of face masks. According to the review, studies showed that cotton and surgical masks had a microorganism filtration efficiency of 86.4% and 99.9% respectively, while the surgical mask was three times more effective in blocking transmission than the cotton mask and could lead to a decrease of the effective reproduction number to below 1 – which could halt epidemic spread in a region – if 70% of residents use them consistently in public.[135][136]

Correct handling and wearing of masks

A properly-worn face mask covers the nose, mouth, and chin. [6] [137]
A face mask is carefully taken off by handling the ties or loops without touching the front. [6] [137]

As masking became widespread during the pandemic, it gave rise to the issue that many individuals of the public are not correctly handling and wearing their masks.[138][139][140] Suzanne Willard, a clinical professor at Rutgers School of Nursing, remarked that the general public is not used to wearing masks and that lay people are asked to use a tool that health care professionals are trained to use.[141]

A commonly-seen issue is that people are wearing masks pulled down below the nose, which is an incorrect way to wear a mask.[142][143] Zane Saul, the chief of infectious disease at Bridgeport Hospital, remarked that "I really have observed people not covering their noses and just covering their mouths. It's just as important to cover your nose."[142] Daniel Gottschall, the vice president of medical affairs for the Fairfield region of Hartford HealthCare and St. Vincent's Medical Center in Bridgeport, explained that "By wearing a mask you're keeping a lot of those secretions inside of you. If you wear it just over your nose or just over your mouth and you're not diligent (about keeping it in place), you're exposing the secretions that come out of that part of the body to other people."[142]

Zeynep Tufekci, a professor of information science, remarked that messaging on masking should have been used to provide proper instructions to the public—as was done for hand washing—rather than used to discourage people from masking because of the possibility that they would wear them improperly, as had happened early in the pandemic.[60] The European Centre for Disease Prevention and Control highlighted that the appropriate usage of face masks in communities could be improved through education campaigns and is key for its effectiveness as a measure.[1] Health institutions such as the World Health Organization have provided public guidance on the "do"s and "don't"s on masking.[6]

Shortages of face masks

Early epidemic in mainland China

People in Wuhan lining up in front of a drug store to buy surgical masks.
A notice at a supermarket in Beijing, which says each person can only buy one pack of surgical masks and one bottle of 84% disinfectant liquid a day.
Chinese electronics manufacturers, such as BYD Electronic, began to produce surgical masks after the outbreak.

As the epidemic accelerated, the mainland market in China saw a shortage of face masks due to increased public demand.[144] Face masks were quickly sold out in stores throughout China.[145] Hoarding and price gouging drove up prices, so the market regulator said it would crack down on such acts.[146][147] In January 2020, price controls were imposed on all face masks on Taobao and Tmall.[148] Other Chinese e-commerce platforms – JD.com,[149] Suning.com,[150] Pinduoduo[151]—did likewise; third-party vendors would be subject to price caps, with violators subject to sanctions.

By March, China had quadrupled its production capacity to 100 million masks per day.[107]

National stocks and shortages

At the beginning of the COVID-19 outbreak in the United States, the U.S.'s Strategic National Stockpile contained just 12 million N95 respirators, far fewer than estimates of the amount required.[152] Millions of N95s and other supplies were purchased from 2005 to 2007 using congressional supplemental funding, but 85 million N95s were distributed to combat the 2009 swine flu pandemic, and Congress did not make the necessary appropriations to replenish stocks.[152] The Stockpile's primary focus has also primarily been on biodefense (defense against a terrorist or weapon of mass destruction attack) and response to natural disaster, with infectious disease a secondary focus.[152] By 1 April 2020, the Stockpile was nearly emptied of protective gear.[153] In January and February 2020, U.S. manufacturers, with the encouragement of the Trump administration, shipped millions of face masks and other personal protective equipment to the PRC, a decision that subsequently prompted criticism given the mask shortage that the U.S. faced during the pandemic.[154]

In France, 2009 H1N1-related spending rose to €382 million, mainly on supplies and vaccines, which was later criticized.[155][156] It was decided in 2011 to not replenish its stocks and rely more on supply from China and just-in-time logistics.[155] In 2010, its stock included 1 billion surgical masks and 600 million FFP2 masks; in early 2020, it was 150 million and zero respectively.[155] While stocks were progressively reduced, a 2013 rationale stated the aim to reduce costs of acquisition and storage, now distributing this effort to all private enterprises as an optional best practice to ensure their workers' protection.[155] This was especially relevant to FFP2 masks, more costly to acquire and store.[155][157] As the COVID-19 pandemic in France took an increasing toll on medical supplies, masks and PPE supplies ran low, causing national outrage. France needs 40 millions masks per week, according to French president Emmanuel Macron.[158] France instructed its few remaining mask-producing factories to work 24/7 shifts, and to ramp up national production to 40 million masks per month.[158] French lawmakers opened an inquiry on the past management of these strategic stocks.[159] The mask shortage has been called a "scandal d'État" (State scandal).[160]

In late March and early April 2020, as Western countries were in turn dependent on China for supplies of masks and other equipment, China was seen as making soft-power play to influence world opinion.[161][162] However, a batch of masks purchased by the Netherlands was reportedly rejected as being sub-standard. The Dutch health ministry issued a recall of 600,000 face masks from a Chinese supplier on 21 March which did not fit properly and whose filters did not work as intended despite them having a quality certificate.[161][162] The Chinese Ministry of Foreign Affairs responded that the customer should "double-check the instructions to make sure that you ordered, paid for and distributed the right ones. Do not use non-surgical masks for surgical purposes".[162] Eight million of 11 million masks delivered to Canada in May also failed to meet standards.[163][164]

Theft

Thefts of face masks and other personal protective equipment have been reported at hospitals in the United States and other countries.[165]

The Naval Medical Center San Diego began mandatory random bag checks for staff members, after several incidents of theft.[166] Hospitals in Canada reported that theft of PPE had become so commonplace that face masks had to be locked away. According to hospital staff, the policy of locking up PPE often resulted in staff requests for PPE being denied.[167] Thefts of N95 masks were reported from a locked hospital office in South Carolina and off loading docks at the University of Washington.[168]

Two thousand surgical masks were stolen from a hospital in Marseilles, France during the early months of the COVID-19 outbreak, in March. The masks were stolen from an area of the hospital that could only be accessed by surgery patients and staff.[169] A hospital employee in Cooperstown, New York was charged with misdemeanor larceny for a similar incident.[170] Hospital employees in West Java were arrested for stealing hundreds of boxes of face masks and selling them on the black market.[171]

One month later an Indiana hospital pharmacy reported a theft to the Drug Enforcement Agency. Along with morphine, with a street value estimated at $3000, the thieves, one of whom was an employee of the hospital and had an access card, had stolen masks and other in-demand goods. In the criminal complaint, filed in Indiana federal court, a DEA task force officer said:[165]

"Based on my training and experience, I know these items are highly sought after in the secondary market due to shortages resulting from the Coronavirus pandemic and that these types of items are being sold on the secondary market at an increased price well over fair market value."

A former hospital employee in Georgia was arrested on allegations of stealing masks and gloves from the hospital on five separate occasions after he was fired.[172] Also in April, an employee of the Charlie Norwood VA Medical Center was charged with a misdemeanor for stealing disposable gowns and surgical masks from the hospital.[173] PPE, including masks, were reported stolen by a member of the housekeeping staff at a hospital in Arizona and a physician's assistant in Florida.[174][175]

According to a BBC News report from August hospital staff in Ghana were selling PPE on the black market.[176]

Two government workers from the Federal Law Enforcement training Center in North Charleston, South Carolina were charged in October for conspiracy to steal PPE, obstruction of justice and lying to the FBI.[177]

N95 and FFP masks

N95 and FFP masks were in short supply and high demand during the COVID-19 pandemic.[178][155] Production of N95 masks was limited due to constraints on the supply of nonwoven polypropylene fabric (which is used as the primary filter), as well as the cessation of exports from China.[33][179] China controls 50 percent of global production of masks, and facing its own coronavirus epidemic, dedicated all its production for domestic use, only allowing exports through government-allocated humanitarian assistance.[33]

United States

In March 2020, US President Donald Trump applied the Defense Production Act against the American company 3M, which allows the Federal Emergency Management Agency to obtain N95 respirators from 3M.[180][181] White House trade adviser Peter Navarro stated that there were concerns that 3M products were not making their way to the US.[180] 3M replied that it has not changed the prices it charges, and was unable to control the prices its dealers or retailers charge.[180]

Jared Moskowitz, the head of the Florida Division of Emergency Management, accused 3M of selling N95 masks directly to foreign countries for cash, instead of the US. Moskowitz stated that 3M agreed to authorized distributors and brokers to represent they were selling the masks to Florida, but instead his team for the last several weeks "get to warehouses that are completely empty." He then said the 3M-authorized US distributors later told him the masks Florida contracted for never showed up because the company instead prioritized orders that came in later, for higher prices, from foreign countries (including Germany, Russia, and France).[182][183][184]

Forbes reported that "roughly 280 million masks from warehouses around the US had been purchased by foreign buyers [on 30 March 2020] and were earmarked to leave the country, according to the broker—and that was in one day", causing massive critical shortages of masks in the US.[185][186]

Masks were still in short supply in late September, eight months into the pandemic. The Defense Production Act powers that averted a ventilator shortage were not used as extensively to increase N95 production, despite outcry from healthcare workers. Even though 3M has increased domestic production from 20 million to 95 million masks a month, they say "the demand is more than we, and the entire industry, can supply for the foreseeable future."[187][188] N95 manufacturers and other companies have been reluctant to invest more in domestic mask production because manufacturing in the United States is not profitable for them. There are some American companies who can shift production temporarily to meet the demand for masks but most of them have not received any funding through the DPA. Some have taken the initiative but there were problems with the fit of the masks and obtaining regulatory approvals. 3M and other N95 manufacturers have not entered into any corporate partnerships to share intellectual property or increase N95 production.[187]

Trump gave Rear Admiral John Polowczyk the responsibility for the logistics of PPE. Polowczyk said that he believed "hospital systems are making management decisions that might lead to an appearance that we still don't have masks, which is the farthest from the truth."[187]

Germany

In early April 2020, the Berlin politician Andreas Geisel alleged that a shipment of 200,000 N95 masks that it had ordered from American producer 3M's China facility were intercepted in Bangkok and diverted to the United States. 3M said they had no knowledge of the shipment, stating "We know nothing of an order from the Berlin police for 3M masks that come from China," and the US government denied that any confiscation had taken place and said that they use appropriate channels for all their purchases.[189][190] Berlin police later confirmed that the shipment was not seized by US authorities.

This revelation outraged the Berlin opposition, whose CDU parliamentary group leader Burkard Dregger accused Geisel of "deliberately misleading Berliners" in order "to cover up its own inability to obtain protective equipment". FDP interior expert Marcel Luthe also criticized Geisel.[191] Politico Europe reported that "the Berliners are taking a page straight out of the Trump playbook and not letting facts get in the way of a good story."[192] The Guardian also reported that "There is no solid proof Trump [nor any other American official] approved the [German] heist".[193]

Canada

As more and more countries restricted the export of N95 masks, Novo Textiles in British Columbia announced plans to start producing N95 masks in Canada.[194] AMD Medicom in Quebec had long been the main Canadian company producing N95s, but China, France, the Republic of China (Taiwan) and the United States all banned exports of medical equipment, barring Medicom's factories there from exporting the masks to Canada. The Government of Canada subsequently awarded Medicom a 10-year contract to build a factory to produce masks in Montreal.[195]

The mask industry

Manufacturing

With population of 24 million, Taiwan has been producing 13 million masks per day since March.

As of 2019, mainland China manufactured half the world output of masks.[196] As COVID-19 spread, enterprises in several countries quickly started or increased the production of face masks.[197] Cottage industries and volunteer groups also emerged, manufacturing cloth masks for localized use. They used various patterns, including some with a bend-to-fit nose piece inserts. Individual hospitals developed and requested a library of specific patterns.[198][199][200][201]

In the first five months of 2020, 70,802 new companies registered in China to make or trade face masks, a 1,256% increase compared to 2019, and 7,296 new companies registered to make or trade melt blown fabrics, a key component of face masks, a 2,277% rise from 2019.[202]

In April, however, the Chinese government stepped in with tighter regulations. 867 producers of the meltblown fabric were shut down in Yangzhong city alone. Many speculative manufacturers have been forced to quit due to changing export rules and tighter licensing requirements in China and weaker demand for lower quality products globally.[202]

Distribution

Some clinical stockpiles have proved inadequate in scale, and the non-medical market demand expanded dramatically as the general public determined that masks were essential, or they began obeying public health mandates, or both.[203]

Between April and June 2020, sellers on Etsy sold 29 million cloth face masks worth an estimated 364 million. Approximately 4 million people, or about 7 percent of buyers on Etsy, came there just to purchase cloth masks.[204]

Society and culture

Attitudes

Slovakia was one of the first countries in the world to introduce universal masking in public places. [205]

In East Asian societies, a primary reason for mask-wearing is to protect others from oneself.[206][207] The broad assumption behind the act is that anyone, including seemingly healthy people, can be a carrier of the coronavirus.[207] The usage of masks is seen as a collective responsibility to reduce the transmission of the virus.[208] A face mask is thus seen as a symbol of solidarity in Eastern countries.[208] Elsewhere, the need for mask-wearing is still often seen from an individual perspective where masks only serve to protect oneself.[206] However, over the course of the pandemic, people began promoting a new meaning of masking as an act of solidarity to each other.[209][210][211][212] Masking is gradually shifting to become a new social norm.[213][214]

Existing cultural norms and social pressure may impede mask-wearing in public, which explains why masking has been avoided in the West.[215] According to Joseph Tsang, a Hong Kong doctor and infectious disease expert, the promotion of universal masking may resolve perceptions against mask-wearing, because mask-wearing is intimidating if few people wear masks due to cultural barriers, but if all people wear masks it shows a message that people are in this together.[59] A study surveying people in Spain showed that an individual's likelihood of voluntarily wearing a mask is positively correlated with the proportion of uptake in the surrounding area.[216]

Helene-Mari van der Westhuizen et al. point out that the successful implementation of public masking policies, especially in communities that has no cultural traditions for such interventions, requires a reframing of social meanings and moral worth, and that public messages help to conceptualize who typically wear masks and what the moral valence of masking is.[217] They note that the earliest members who wear face coverings may be seen as deviant when the community starts to adopt masking, but that changing narratives will generate new meanings that construe those that do not mask as deviant.[217] Their argument is that public health messaging about face coverings should shift from masks as a medical intervention to masks as a social practice based on values such as social responsibility and solidarity, as a successful uptake requires face coverings to be grounded in the social and cultural realities of affected communities.[217] Clemens Eisenmann and Christian Meyer argue that the question, how the meaning of wearing face masks develops in society, depends on their practical and public uses within everyday social interactions.[218] They explain that masking has destabilized interactional infrastructures embedded in routines, revealing both taken-for-granted infrastructures of everyday life—including social inequalities (such as those of people reliant on lip reading) and moral evaluations in transcultural situations (such as those involving implicit racism in which the health instructions of essential workers belonging to certain groups are disregarded)—and new challenges on the interactional level.[218]

In the Western world, the public usage of masks still often carries a large stigma,[206][208][219] as it is seen as a sign of sickness.[219] This stigmatization is a large obstacle to overcome, because people may feel too ashamed to wear a mask in public and therefore opt to not wear one.[220] There is also a divide within the Western world, as seen in the Czech Republic and Slovakia where mass mobilization has occurred to reinforce the solidarity in mask-wearing since March 2020.[206]

The Egyptian Theater in Boise, Idaho presents a public health message on its marquee
High school field hockey players in Hudson, Ohio wearing face masks on the sidelines

Mask-wearing has been called a prosocial behavior in which one protects others within their community.[221][222][223] On social media, there has been an effort with the #masks4all campaign to encourage people to use masks.[224] Nevertheless, there have been many occurrences of violence and hostility by people who became aggressive after they were requested to wear a mask or saw people wearing masks in customer-based establishments.[225][226][227][228] Multiple people have been killed in attacks by people who refused to mask.[229] It has led to concerns about worker safety, so employees have been discouraged to actively enforce masking policies due to the potential of hostile situations, while enforcement by official authorities is severely lacking.[230]

Masking has been subjected to racial politics in Western countries.[231] For instance, it has been heavily racialized as an Asian phenomenon.[208][218] This has been reinforced in a lot of media discourses, where stories about the pandemic are often accompanied by unrelated imagery of Asian people in masks.[231][232] The focus on race has brought hostility towards Asians who are confronted with the choice to mask as precaution while they face discrimination for it.[231][233] Huang Yinxiang, a sociologist from the University of Manchester, described maskaphobia—negative prejudice, fear or hatred against people wearing face masks—as making Asians in Western countries into targets for racists who want to legitimize xenophobia during the COVID-19 outbreak.[234] Likewise, people from certain groups such as Black Americans may not feel comfortable wearing masks, especially those that are not clearly medical but homemade masks, due to concerns of racial profiling.[235][236][237]

A sign language interpreter (on the right) is wearing a transparent mask to allow lip reading.

There have also been concerns that the wearing of masks may also further isolate disadvantaged communities. Concerns had been expressed that masks would make communication difficult for people who are deaf or hard-of-hearing.[238][239] This led to calls for wider distributions of transparent masks, which allow for lip reading.[238][239] Similar concerns over difficulty in communicating have been expressed by those who may depend on dogs for therapeutic or social reasons, as the animals depend on body language such as facial expressions.[240] Conversely, people who are exempt from wearing masks on medical grounds or due to a disability, fear they will be subjected to abuse for not wearing a mask, even if they are legally exempt from doing so.[241] For instance, in the United Kingdom, the charity Disability Rights UK received numerous reports about people being confronted on trains and buses.[241] Health organizations such as the American Lung Association commented that, even though there may be people who will seek an exemption, the individual's concerns needs to be weighed against the societal needs to limit the spread of the virus.[242][243] However, anti-maskers have called upon bogus claims about legal or medical exemptions in their refusal to mask.[242] They have, for instance, claimed that the Americans with Disabilities Act (designed to prohibit discrimination based on disabilities) allows exemption from mask requirements, but the United States Department of Justice responded by stating that the act "does not provide a blanket exemption to people with disabilities from complying with legitimate safety requirements necessary for safe operations."[244]

There are feelings of mask fatigue among the general public, which is exacerbated by frustrations about people who are not taking the mask and other guidelines seriously as the pandemic and its intensity continues on.[245]

Trends

Among the European countries surveyed by YouGov, the likelihood for people to mask has been split: In Northern Europe (e.g., Finland, Sweden, Norway, and Denmark), people are very unlikely to wear a mask.[246] In Western Europe (e.g., Italy, Spain, France, and Germany), people were initially unlikely to use a mask, but mask wearing greatly changed from low levels in March to higher levels in May.[246] An exception was the United Kingdom where mask usage only grew gradually during this time,[246] but it rose very quickly after official policy changes in July mandated masking in stores.[247]

A survey among people from the United States (conducted from April to June 2020) indicates that age was a factor on whether people were likely to wear a mask, as the likelihood rose with the age group, but the reported use of face masks increased significantly across all age groups over time.[248] Furthermore, people who did not report mask use also reported engaging in significantly fewer other mitigation behaviors than those who did report mask use.[248]

Gender plays a role in the willingness to wear masks during the pandemic; men are overall less inclined to mask in public than women.[249][250][251] There are indications that men are more likely to feel negative emotions (such as shame) and stigma for wearing masks.[249][250] It is suggested that this male behavior is driven by a sense of masculinity, where the act of masking is possibly perceived to run counter to it, which leads to an increase in men not wearing masks during the pandemic.[252][253] A survey among participants recruited from Amazon Mechanical Turk about face mask perceptions found that men and women may have different reasons when they do not wear masks in public: Men were more likely to see masks as an infringement upon their independence and women were more likely to perceive masks as being uncomfortable, while perceptions on efficacy, accessibility, compensation, inconvenience, appearance, and attention did not differ.[254]

Governmental role

The heads of state and government of Portugal and Spain wearing face masks during an official ceremony in July 2020.

The pandemic has raised questions about the role of governments in mask policies, either voluntary or mandatory policies, especially in terms of the social and behavioral consequences involving the general public.[223]

The results from a study surveying people in Germany indicate that the act of wearing a mask, independent of the policy, is considered a social contract in which compliant people perceive each other more positively and noncompliance is negatively evaluated.[223] However, it also suggests that voluntary policies have the potential effect to increase polarization and thus cause more stigmatization.[223] The authors recommended that countries and communities should adopt a mandatory policy along with explicit communication of the benefits of both masking (e.g., risk reduction, mutual protection, positive social signaling) and mandatory policies (e.g., fairness, less stigmatization, higher effectiveness) to encourage the public to wear masks.[223]

World leaders as role models for masking have also received much scrutiny, as they are key to convey the critical public health message to the public.[255][256] For example, Slovakia has been cited as a country where its public figures—including President Zuzana Čaputová and her administration—set the example by wearing masks and played a crucial role to normalize masks.[257] In contrast, in the United States, President Donald Trump and his administration have come under criticism for communicating an inconsistent and confusing message about masking.[258][259] They have often been criticized for undercutting national and local public health advice to wear masks.[260][261]

Politics

U.S. Surgeon General Jerome Adams urged people to wear face masks and acknowledged that it is difficult to correct earlier messaging that masks do not work for the general public. [262]

Although authorities, especially in Asia, have been recommending people to wear face masks in public, in many other parts of the world, conflicting advice has caused much confusion among the general population.[263] Several governments and institutions, such as in the United States, initially dismissed the use of face masks by the general population, often with misleading or incomplete information about the usefulness of masks.[264][265][266] Commentators have attributed the anti-mask messaging to efforts to manage the mask shortages, as governments did not act quickly enough, remarking that the claims go beyond the science or were simply lies.[266][267][268][269] On 12 June 2020, Anthony Fauci, a key member of the White House coronavirus task force, confirmed that the American public were not told to wear masks from the beginning due to the shortages of masks and explained that masks do actually work.[270][271][272][273][274]

Anti-pandemic precautions during the 2020 Czech regional elections.

In the United States, public masking has become a political issue, as opponents argue that it inhibits personal freedom and proponents emphasize the importance of masks for public health.[275] Some people may see it as a political statement.[276] Party affiliation partly determined how likely people were to embrace the wearing of masks in public.[276][277] Democrats were more likely to wear masks than Republicans.[276][277] Masks have become an aspect of the culture war that has emerged over the course of the pandemic.[275][276][277] Commentators argue that the resistance against masks partly stems from the confusing and mixed messaging about masking.[275][278][279]

Matthew Facciani, a sociologist at Vanderbilt University, states that the uncertainty from health experts during the early days of the pandemic paved the way for political leaders to become a prominent source for guidance and clarity.[280] He argues that, once mask wearing became informed by political beliefs, it is difficult to correct due to the motivation to protect one's identity in relation to a political group and the reinforcement from political echo chambers, no matter that scientists began to better understand the severity of the virus and the evidence in favor for mask wearing became clearer.[280]

In April 2020, health officials from Taiwan's Central Epidemic Command Center (CECC) pushed back on school bullying of boys in pink face masks.[281] The CECC officials and Minister of Health and Welfare Chen Shih-chung wore pink masks to challenge gender norms at a press conference, while various government agencies demonstrated solidarity by changing the colors on their Facebook pages to pink.[281] The minister later tweeted "Pink is for everyone and no colour is exclusive for girls or boys. Gender Equality lies at the heart of Taiwan values."[281] The press conference was held amid reports that male students were too embarrassed to wear their pink face masks, jeopardizing their safety and the safety of others in the face of COVID-19.[281]

Anti-maskers

In some countries, large rallies have taken place in protest against masking mandates.[282][283][284] In Canada the anti-mask crowd has hailed their protests as the so-called "March to Unmask".[284][285] In the United Kingdom, new protests came in the wake of the official announcement that masking will be compulsory in shops.[282] After 8 months since the beginning of the lockdown in Czech Republic, mass manifestations against the restrictions imposed by the government arose.[286][287] Some anti-mask protestors have co-opted the feminist slogan "my body, my choice"[288][289][290] and the Black Lives Matter slogan "I can't breathe".[291][292] Businesses have also been purposely disrupted by anti-maskers (purportedly in defense of their constitutional rights).[293]

According to Moe Gelbart, Executive Director of the Thelma McMillen Recovery Center, anti-maskers' behaviors do not appear only from the facts they hear, but the problems also come from the meaning they give to those facts. He identifies several key psychological reasons that prompt them to not wear a mask: Firstly, denial is seen in some people who feel worried and anxious by masks as it interferes with their belief and desire that everything is alright. Secondly, another reason is a sense of invulnerability, as some people and especially younger individuals believe that nothing bad will happen to them and are thus prone to risk-taking behaviors. Thirdly, behavioral drift is seen among some people who find it difficult to maintain behaviors intended for prevention rather than treatment. Fourthly, some people may have issues related to authority due to mistrust of science or tribe identification with powerful figures. Fifthly, the meaning of covering one's face is often associated with bad things that people want to hide or are ashamed of. Sixthly, some people do not want to admit fear and vulnerability, which they associate with the act of wearing a mask. Finally, some people have selfish and self-centered reasons, because the call to wear a mask for the protection of others seems to provide not enough motivation to do something that they do not want to do.[294]

In the United States, opposition to mask-wearing during the COVID-19 pandemic came during then President Donald Trump's politicization of science[295] and more generally during decades-old period of politicization of science. But American opposition to mask-wearing during pandemics is not new; during the 1919 influenza pandemic, the Anti-Mask League was established in San Francisco, California.[296]

Religion

Christian clergy from the Lutheran, Catholic, Presbyterian, Anglican, Baptist and Mormon traditions, as well as those from the Jewish, Buddhist and Unitarian religions have implored people to wear masks.[297]

Fashion

Cloth face mask in a style that matches the outfit.

As the pandemic progressed, people began embracing face masks as fashion items in addition to their primary function as a health measure and made them a means of self-expression.[298][299][300][301] For instance, people started to match their face masks to their outfits.[302][303]

Early in the pandemic, people and businesses from the fashion industry responded to official calls for help in overcoming the shortages of protective personal equipment including face masks.[304] These masks were made to be straightforward and standard, as the main consideration at the time was function.[305] Even though it began as a medical necessity for a pandemic, it also gradually evolved into a new category of accessories subject to similar design and marketing considerations as other accessories.[306] Fashion brands eventually reopened their factories for production due to the increasing demand for masks and started to manufacture masks in a wider variety of styles.[299] Smaller brands, who primarily sold their products online, found that selling masks was a good strategy to maintain sales.[307] Etsy became a major online platform where many designers sold their masks.[307] Designers started to make masks that matched other pieces of clothing and accessories,[308][309] which may have started unintentionally by some designers as remaining fabrics were being repurposed for masks during the health crisis.[309]

The city of Vilnius in Lithuania held a "Mask Fashion Week" in May 2020, which was promoted with billboards (with no catwalks or displays) around the city featuring local people including Mayor Remigijus Simasius wearing face masks.[310]

The Walt Disney Company introduced uniform face masks for their employees at Disney World and Disneyland in the United States.[311][312]

Environment

Large amounts of disposal face masks have been discarded throughout the pandemic, which has led to an increase in plastic waste negatively impacting the environment.[313][314][315]

Comparison by countries and territories

Face mask laws around world.
% of population wearing face masks in public, by country/territory (as of 9 August) [316]
Country/territory %
Singapore Singapore 92
Spain Spain 90
Thailand Thailand 88
Hong Kong Hong Kong 86
Japan Japan 86
Malaysia Malaysia 85
Indonesia Indonesia 85
Philippines Philippines 84
France France 83
India India 82
Italy Italy 81
China China 80
Taiwan Taiwan 80
Vietnam Vietnam 79
United Arab Emirates United Arab Emirates 79
United Kingdom United Kingdom 75
United States United States 75
Canada Canada 74
Saudi Arabia Saudi Arabia 71
Mexico Mexico 67
Germany Germany 65
Australia Australia 41
Poland Poland 23
Greece Greece 19
Russia Russia 10
Egypt Egypt 8
Finland Finland 7
Sweden Sweden 6
Norway Norway 5
Denmark Denmark 4
  • Argentina Argentina: After appearance of three asymptomatic cases, the capital Buenos Aires introduced compulsory masking since 14 April. Wearing a mask was made obligatory for everyone on public transit and everyone who contacts with the public in their position. Violators can face a fine. Authorities also prohibited the sale of N95 face masks to non-medical workers, suggesting the general public to use home-made masks instead.[317]
  • Australia Australia: The federal Department of Health does not recommend the wearing of face masks by the general public, but in regions where there is community transmission people may consider using a mask. In places where there is community transmission and it is difficult to keep a distance, masks are recognized as an important protective measure, but only if used properly.[318] In the state of Victoria, face coverings became compulsory on 22 July in the metropolitan Melbourne or Mitchell Shire areas when outside of one’s home.[319] This was later extended to all of Victoria from 3 August.
  • Austria Austria: Everyone entering a supermarket, a grocery store, or a drug store or using public transportation must wear a face mask, mandatory since 14 April.[320][321][322]
  • The Bahamas Bahamas: On 19 April, the prime minister announced that wearing a mask or covering one's face with clothing is mandatory in public. Employers must provide their employees who are serving the general public with masks.[323]
  • Bahrain Bahrain: The Kingdom made wearing face masks in public areas compulsory for citizens and residents as well as shop workers.[324]
  • Benin Benin: From 8 April, Benin's authorities began enforcing the mandatory wearing of face masks to halt the coronavirus.[325]