Face masks during the COVID-19 pandemic

Last updated

US Ambassador to Indonesia Sung Kim accompanied by local officials at the Presidential Palace wearing face masks amid the COVID-19 pandemic Duta Besar Baru AS Sung Kim Serahkan Surat Kepercayaan Pada Presiden Jokowi (50515038461).jpg
US Ambassador to Indonesia Sung Kim accompanied by local officials at the Presidential Palace wearing face masks amid the COVID-19 pandemic

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. In both community and healthcare settings, their use is intended as source control to limit transmission of the virus and personal protection to prevent infection. [1] Their function for source control is emphasized in community settings.

Contents

The use of face masks (or coverings in some cases) has been recommended by American immunologist and NIAID director Anthony Fauci to reduce the risk of contagion. [2]

Types of masks

In the COVID-19 pandemic, governments recommend the use of face masks with a main purpose for the general population: to avoid the contagion from infected people to others. Masks with exhalation valves are not recommended, because they expel the breath of the wearer outwards, and an infected wearer would transmit the viruses through the valve. A second purpose of the face masks is to protect each wearer from environments that can be infected, which can be achieved by many models of masks. [3]

Between the different types of face masks that have been recommended throughout the COVID-19 pandemic, with higher or lower effectivity, it is possible to include:[ citation needed ]

There are some other types of personal protective equipment (PPE), as face shields and medical goggles, that are sometimes used in conjunction with face masks but are not recommended as a replacement. [4] Other kinds of PPE include gloves, aprons, gowns, shoe covers and hair covers. [5]

There have been shortages of masks, which has led to the use of uncertified masks, with a worse performance. [6]

Cloth masks

Cloth face masks Twoclothfacemasks101.jpeg
Cloth face masks

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,[ citation needed ] some 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 commonly available fabrics used in cloth masks found that cloth masks can provide significant protection against the transmission of particles in the aerosol size range, with enhanced performance across the nano- and micronscale when masks utilize both mechanical and electrostatic-based filtration, but that leakage due to improper fit can degrade performance. [10] A review of available research published in January 2021 concludes that cloth masks are not considered adequate to protect healthcare practitioners in a clinical setting. [11]

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, [12] and found the number of microscopic particles that leaked to the inside of the homemade masks were twice that of commercial masks. Wearing homemade masks also leaked a median average of three times as many microorganisms as commercial masks. But another study found that masks made of at least two layers T-shirt fabric could be as protective against virus droplets as medical masks, and as breathable. [13]

Many people made cloth face masks at home during the pandemic. Woman sewing a face mask with a Singer machine 09.jpg
Many people made cloth face masks at home during the pandemic.
World Health Organization infographic on how to wear a non-medical fabric mask safely. How to wear a non-medical fabric mask safely - Do's & Don'ts.png
World Health Organization infographic on how to wear a non-medical fabric mask safely.

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. [15]

There is a necessary trade-off: increasing the number of layers increases the filtration of the material but decreases breathability. Decreased breathability makes it harder to wear a mask and also increases the amount of leak around the edge of the mask. A plain-language summary of this work, [16] along with a hand-sewn design, [17] suggestions on materials and layering, [18] and how to put on, [19] take off, [20] and clean cloth masks are available. [21]

As of May 2020, there was no research on decontaminating and reusing cloth masks. [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 twenty seconds. Cold water is considered as effective as warm water for decontamination. [22] The CDC also recommends washing hands before putting on the mask, and again immediately after touching it. [23]

There is no information on reusing an interlayer filter. Disposing of filters 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, [15] or a PM2.5 filter, as a third layer. [24]

Surgical masks

World Health Organization infographic on how to wear a medical mask safely How to a wear medical mask safely - Do's & Don'ts.png
World Health Organization infographic on how to wear a medical mask safely

A surgical mask is a loose-fitting, disposable mask that creates a physical barrier separating the mouth and nose of the wearer from 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 them from reaching the wearer's mouth and nose. Surgical masks may also help reduce exposure of others to the wearer's saliva and respiratory secretions. [25]

Certified medical masks are made of non-woven material and 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). [26] [27] [28] [ better source needed ][ medical citation needed ] While there is some development work on making electret filtering materials that can be washed and reused, [29] 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. [30] 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. [30] [31] Standard disposable surgical masks are not designed to be washed. Surgical masks may be labeled as surgical, isolation, dental, or medical procedure masks. [25] The material surgical masks are made from is much poorer at filtering very small particles (in range a tenth of a micrometre to a micrometre across) than that of filtering respirators (for example N95, FFP2) and the fit is much poorer. [25] Surgical masks are made of a non-woven fabric created using a melt blowing process. [32] [33] Random control studies of respiratory infections like influenza find little difference in protection between surgical masks and respirators (such as N95 or FFP masks). [34] However, the filtering performance of correctly worn N95/FFP2 type filtering respirators is clearly superior to surgical and to cloth masks [35] and for influenza, work by the UK Health and Safety executive [36] found that live virus penetrated all surgical masks tested but properly fitted respirators reduced the viral dose by a factor of at least a hundred.

Tsai Ing-wen, President of Taiwan, wearing a surgical mask 04.02 Zong Tong Shi Cha [Zhong Yang Liu Xing Yi Qing Zhi Hui Zhong Xin ]  49726568957 66543b616e o.jpg
Tsai Ing-wen, President of Taiwan, wearing a surgical mask

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. [37] [38] [39]

Modifications

The effectiveness of surgical masks in limiting particle transmission is a function of material and fit. [40] Since the start of the pandemic, scientists have evaluated various modifications to ear loop surgical masks aimed at improving mask efficacy by reducing or eliminating gaps between the mask and face. [41] The CDC evaluated and recommends two such modifications to ear loop masks to reduce transmission of SARS-CoV-2. Under normal use, the CDC found that a surgical mask worn by a coughing individual blocked 41.3% of simulated cough aerosols (0.1–7.0 μm particle size) from reaching a second individual six feet away. However, by applying a knot and tuck technique, [lower-alpha 1] 62.9% of particles were blocked. When the surgical mask was covered with a larger cloth mask, 82% of particles were blocked. When both the source and recipient wore masks, 84% of particles were blocked. The number increased to more than 95% when both parties either wore double masks (surgical mask with larger cloth mask) or used the knot and tuck technique. [42]

Another type of modifications was aimed to improve the comfort of the wearers. Early on in the pandemic, healthcare workers were required to continue wearing surgical masks for 12 or more hours a day. This caused the ear loops of the masks to chafe the back of their ears. Ear savers, plastic straps and hooks that go around wearer's heads, were invented to move the ear loops away from the wearer's ears. They could be made on demand by using 3D printing process. [43]

Filtering respirators

N95 mask 3M N95 Particulate Respirator.JPG
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 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. [44] It is an example of a mechanical filter respirator, which provides protection against particulates, but not gases or vapors. [45] Like the middle layer of [46] surgical masks, the N95 mask is made of four layers [9] of melt-blown nonwoven polypropylene fabric. [47] [48] [ unreliable medical source? ] The corresponding face mask used in the European Union is the FFP2 respirator. [49] [50]

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 [51] has been shown to reduce edge leakage [9] in lab tests using mannequins t hat simulate breathing. [51]

Some N95 series respirators, especially those intended for industrial use, have an exhalation valve to improve comfort, making exhalation easier and reducing leakage on exhalation and steaming-up of glasses. But those respirators are not reliable for the control of infected people (source control) in respiratory diseases such as COVID-19, because infected users (asymptomatic or not) would transmit the virus to others through the valve. [52]

During the COVID-19 pandemic, there were shortages of filtering facepiece respirators, and they had to be used for extended periods, and/or disinfected and reused. At the time, public health authorities issued guidelines on how to save, disinfect and reuse masks, as some disinfection methods damaged their filtration efficiency. [30] [31] Some hospitals stockpiled used masks as a precaution, [53] and some had to sanitize and 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 200323-Z-NI803-0964.jpg
A medical worker wearing a face shield adjunct to other personal protective equipment at a COVID-19 testing site

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. [54] 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 few 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. [55]

In a scoping review, Godoy et al. (5 May 2020) said 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 the protection was decreased with smaller aerosol particles and persistent airborne particles around the sides. [56]

A systematic review of observational studies on the transmission of coronaviruses, funded by the World Health Organization 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. [57]

Elastomeric respirators

Surgeons wearing full-facepiece elastomeric respirators (gas masks) while doing tracheostomy to a COVID-19 patient in Russia Syrchin45.jpg
Surgeons wearing full-facepiece elastomeric respirators (gas masks) while doing tracheostomy to a COVID-19 patient in Russia

Elastomeric respirators are reusable personal protective equipment comprising a tight-fitting half-facepiece or full-facepiece respirator with exchangeable filters such as cartridge filters. [58] 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. [58] [59] However, elastomeric respirators have a vent to exhalate the air outwards and unfiltered, so the wearer must be attentive that he or she is not infected with SARS-CoV-2, to prevent a possible transmission of the virus to others through the vent. [59]

For the COVID-19 response when supplies are short, the US CDC says 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. [58]

Powered air-purifying respirators

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. [60]

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. [60] [61]

In a systematic review, Licina, Silvers, and Stuart (8 August 2020) said 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. [62]

Face masks with exhalation valves

Flow visualization of an N95 respirator with and without an exhalation valve using schlieren imaging and light scattering (mannequin).jpg
Flow visualizations comparing face mask efficacy with and without exhalation valve, illustrating the concern that exhalation valves allow exhaled respiratory droplets to reach others in proximity and would therefore not be appropriate in source control strategies. [63]

Some masks include an exhalation valve to expel the breath outwards, but that current of air is not filtered. Certification (as N95 or FFP2) is about the mask itself and does not warrant any safety about the air that is exhaled. Putting tape over the exhalation valve can make a mask or respirator as effective as one without a valve. [64]

Scientists have visualized droplet dispersal for masks with exhalation valves and face shields, and concluded that they can be ineffective against COVID-19 spread (e.g., after a cough) and recommended alternatives. [65] [66]

Recommendations

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. [67] [68] The recommendations have changed as the body of scientific knowledge evolved. [69]

According to #Masks4All, about 95% of the world population lives in countries where the government and leading disease experts recommend or require the use of masks in public places to limit the spread of COVID-19. [70]

World Health Organization

A video from the World Health Organization regarding different types of face masks and how to use them

Early in 2020, 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. [71] [72] [73] In April 2020, the WHO acknowledged that wearing a medical mask can limit the spread of certain respiratory viral diseases including COVID-19, but claimed that medical masks would create a false sense of security and neglect of other necessary measures, such as hand hygiene. [73]

The early WHO advice on limited mask usage was scrutinized for several reasons. First, experts and researchers pointed out the asymptomatic transmission of the virus. [74] [75] [76] [77] [78] Second, according to Marteau et al. (27 July 2020), available evidence does not support the notion that masking adversely affects hand hygiene: [79] 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." [80]

The WHO revised its mask guidance in June 2020, with its officials acknowledging that studies indicated asymptomatic or pre-symptomatic spread. [81] The updated advice recommended 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 (60 and over, or with underlying health risks) and people with any symptoms suggestive of COVID-19 as well as caregivers and healthcare workers should wear surgical or procedure masks. [68] 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). [68]

The WHO advises that non-medical fabric masks should comprise a minimum of three layers, [68] 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. [82]

On 21 August 2020, the WHO and UNICEF released an annex guidance for children. [83] For children five and 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 countries may hold a different and lower age of cut-off. [83] For children 6–11, 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). [83] For children 12 and older, they advise that masks should be worn under the same conditions for adults in accordance to WHO guidance or national guidelines. [83]

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. [84]

United States Centers for Disease Control and Prevention

Guidance from the US Centers for Disease Control and Prevention on using and making cloth masks during the COVID-19 pandemic Use of Cloth Face Coverings to Help Slow the Spread of COVID-19.pdf
Guidance from the US Centers for Disease Control and Prevention on using and making cloth masks during the COVID-19 pandemic

Early in 2020, the United States Centers for Disease Control and Prevention (CDC) said it did not recommend the use of face masks for the general public. [86] [87] 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". [88] [89] In response to a media inquiry by National Public Radio, 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. [90] In a subsequent interview and JAMA editorial, the CDC director Robert R. Redfield explained that the CDC's early guidance had been premised on an initial absence of evidence of disease transmission from pre- and asymptomatic individuals. [91] [92] [93]

The CDC does not recommend masks with exhalation valves or vents for source control. 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. Atemluftfilter Einwegmaske.jpg
The CDC does not recommend masks with exhalation valves or vents for source control. 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.

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." [95] The CDC provides the caveat that cloth face coverings should not be worn by children under the age of two, people who have trouble breathing, or people who are unconscious, incapacitated, or otherwise unable to remove the mask without assistance. [95] In August 2020, 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. [54] [96]

In a 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. [97] They say the community's 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). [97] For filtration, the CDC says some fabrics (such as silk) may hydrophobically repel moist droplets, whereas other fabrics (such as polyester or polypropylene) may electrostatically capture droplets. [97] 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. [97]

The CDC said 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. [98] 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. [99]

In late July 2021, the CDC changed guidelines to recommend people, including those who are vaccinated, to continue masking in public indoor settings in areas with substantial and high transmission—as there are indications that the coronavirus such as the Delta variant may infect even vaccinated people in rare occasions—to help prevent transmission to other people. [100] [101] Previously, the CDC updated public guidance from May 2021 stated that those who are fully vaccinated can "resume activities without wearing masks or physically distancing, except where required by federal, state, local, tribal, or territorial laws, rules and regulations, including local business and workplace guidance." [102] However, critics posited that it was predicated on a key social factor, namely whether people can be trusted to wear a mask if they are not fully vaccinated. [103] [104] [105]

Criticism of guidance

Larry Gostin, a professor of public health law, said initial CDC and WHO guidance had given the public the wrong impression that masks do not work, even though scientific evidence to the contrary was already available. [90] The confusing changing advice from discouraging to recommending public masking has led to decreasing public trust in the CDC. [76] [106] 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. [107]

China and Asia

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." [108]

Europe

Most countries in Europe have introduced mandatory face mask rules for public places. [109] [110] On 8 April 2020, the European Centre for Disease Prevention and Control (ECDC) published its masking recommendations, saying that the "use of face masks in the community could be considered, especially when visiting busy, closed spaces". [111] [67] On 15 February 2021, ECDC updated the recommendation stating "Although the evidence for the use of medical face masks in the community to prevent COVID-19 is limited, face masks should be considered as a non-pharmaceutical intervention in combination with other measures as part of efforts to control the COVID-19 pandemic." [112]

The Nordic countries and the Netherlands have been a notable exception to supporting the use of face masks, [110] [113] but eventually started to recommend masks. For example, due to the COVID-19 pandemic in the Netherlands, wearing a mouth/nose mask was made mandatory on public transportation per 1 June 2020. [114] 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. [115] In June 2020, the Norwegian Institute of Public Health said asymptomatic individuals wearing face masks 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. [116] Similarly, on 30 July 2020, the Danish Health Authority director Søren Brostrøm said 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. [117] [118] 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. [119] In many Norwegian local municipalities, face masks are mandatory on public transport where a social distance of one metre is impossible to maintain. [120]

Sweden in particular stands out as a country where face masks have not been recommended to the general public and the State Epidemiologist of Sweden, Anders Tegnell, has been an opponent to face masks among the general population, although he has said that face masks might be suitable on work places where people are one to two meter from each other's for more than fifteen minutes, something which some Swedish and foreign media have interpreted as a recommendation. [121] [122] This position was slightly reversed when Prime Minister of Sweden, Stefan Löfven, announced that they were recommending face masks on 18 December 2020. [123] The Public Health Agency of Sweden later clarified on their website that the recommendation would include citizens born before 2004 to wear masks during rush hour on public transportions throughout the country from 7 January 2021 onward. [124] On 20 December 2020, two days after the announcement was made, Prime Minister Löfven was paparazzied in a shopping mall in central Stockholm without wearing a face mask. [125] By 22 January 2021 the Stockholm Public Transport estimated that about half of all passengers on trains and busses wore face masks during rush hour. [126] Among those who chose not to follow the recommendation were Johan Carlson, the Director-General of the Public Health Agency, and Anders Tegnell, the state epidemiologist. [127] [128]

Rationale for wearing masks

Schlieren image showing the interaction of exhaled airflows between two people Two subjects in position in front of the schlieren mirror. Figure 4, Journal.pone.0021392.g004.png
Schlieren image showing the interaction of exhaled airflows between two people

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. [1] [130] [131]

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. [132]
  2. Difficulty or impossibility of appropriate social distancing in many public places at all times. [132]
  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. [132]
  4. There is no shortage of masks in China. The country has the production capacity to meet the demand on masks. [132]

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. [133] Wang Linfa, an infectious disease expert who heads a joint Duke University and National University of Singapore research team, said 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. [75] 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. [134]

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. [135] 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. [136]

Monica Gandhi, a medical professor at the University of California, San Francisco, says viral shedding at high quantities from the upper respiratory tract, characterized by unusually high levels of viral particles, means universal mask wearing is one of the best ways to limit the asymptomatic spread of the virus. [137] 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. [138]

In a perspective, Monica Gandhi, Chris Beyrer, and Eric Goosby posit that masking reduces the dose of the virus for the wearer and thus helps lower the severity of infection. [139] They highlighted that the proportion of asymptomatic and mild infection increased in settings adopting population-level masking. [139] 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. [139]

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. [140] Others agreed, based on the evidence-based principle that the likely benefits outweighed the likely harms. [141] [142]

Leonardo Setti et al. argue that face masks should be used to complement social distancing of six feet or two 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. [143] 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. [144] 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. [144]

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." [145] 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). [146]

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. [147]

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. [148]

Efficacy studies for COVID-19

A WHO-funded systematic review 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. [57] 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. [57]

The CDC highlighted a number of studies in their 10 November 2020 scientific brief detailing the benefits of community masking. [134] 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%. [149] A retrospective case-control study from Thailand documented that, among more than 1,000 people 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 people who did not wear masks under these circumstances. [150] A case study from July 2020 detailed that 139 clients exposed to two symptomatic hair stylists with confirmed COVID-19 (both the clients and the stylists wore face coverings) resulted in no symptomatic cases reported among all clients and no positive tests among the 67 people who volunteered to be tested. [151] 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. [152] Investigations involving infected passengers aboard flights longer than ten 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. [153] In addition, the CDC said 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. [134]

In addition to studying the impact of mask wearing on transmission in a community, direct studies can be done on whether or not a mask filters out virus-carrying particles from the air. A study of the fabric of masks worn in the community found that they filtered out between half and three-quarters of the viral RNA. [154] Respirators made to a standard such as N95 or FFP2 when properly fitted should filter out at 95% of the virus.

Optimal face mask designs and use

A scientific review of research about the overall efficacy of face masks in terms of product design (such as thermal comfort and flow resistance) and ways of usage found that fluid dynamics and fabrication techniques have a significant impact on performance. 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 where 70% of residents use them consistently in public. [155] [156]

By January 2021 several lines of research recommended double-masking (wearing a cloth mask over a surgical mask, along with using a mask filter, or wearing a nylon covering over a mask) as being efficacious. [157]

Correct handling and wearing of masks

A properly-worn face mask covers the nose, mouth, and chin. 17.Before.NDOP.BaltimoreMD.30May2020 (50021311482).jpg
A properly-worn face mask covers the nose, mouth, and chin.

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. [159] [160] [161] Suzanne Willard, a clinical professor at Rutgers School of Nursing, remarked that the general public is not used to wearing masks and lay people are asked to use a tool health care professionals are trained to use. [162]

A commonly-seen issue is that people are wearing masks pulled down below the nose, which is an incorrect way to wear a mask. [163] [164] 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." [163] 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." [163]

A face mask is carefully taken off by handling the ties or loops without touching the front. Gov. Wolf Announces $225 Million Grant Program for Small Businesses Impacted by COVID-19 (49984832558).jpg
A face mask is carefully taken off by handling the ties or loops without touching the front.

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. [76] The European Centre for Disease Prevention and Control highlighted that appropriate use of face masks in communities could be improved through education campaigns and is key for its effectiveness as a measure. [67] Health institutions such as the World Health Organization have provided public guidance on the "do"s and "don't"s on masking. [14]

Shortages of face masks

Early epidemic in mainland China

As the epidemic accelerated, the mainland market in China saw a shortage of face masks due to increased public demand. [165] Face masks were quickly sold out in stores throughout China. [166] Hoarding and price gouging drove up prices, so the market regulator said it would crack down on such acts. [167] [168] In January 2020, price controls were imposed on all face masks on Taobao and Tmall. [169] Other Chinese e-commerce platforms  JD.com, [170] Suning.com, [171] Pinduoduo [172]  did likewise; third-party vendors would be subject to price caps, with violators subject to sanctions.[ citation needed ]

By March, China had quadrupled its production capacity to a hundred million masks per day. [132]

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 twelve million N95 respirators, far fewer than estimates of the amount required. [173] 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. [173] 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. [173] By 1 April 2020, the Stockpile was nearly emptied of protective gear. [174] 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. [175]

In France, 2009 H1N1-related spending rose to €382 million, mainly on supplies and vaccines, which was later criticized. [176] [177] It was decided in 2011 to not replenish its stocks and rely more on supply from China and just-in-time logistics. [176] In 2010, its stock included a billion surgical masks and 600 million FFP2 masks; in early 2020, it was 150 million and zero respectively. [176] 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. [176] This was especially relevant to FFP2 masks, more costly to acquire and store. [176] [178] 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 forty million masks per week, according to French president Emmanuel Macron. [179] France instructed its few remaining mask-producing factories to work 24/7 shifts, and to ramp up national production to forty million masks per month. [179] French lawmakers opened an inquiry on the past management of these strategic stocks. [180] The mask shortage has been called a "scandal d'État" (State scandal). [181] Thousands of French individuals and companies teamed up during the outbreak to form a decentralized network of Fab labs and ad-hoc retooled production facilities, producing more than a million face shields, masks and other kinds of PPE during the height of the pandemic. [182]

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. [183] [184] 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. [183] [184] 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." [184] Eight million of eleven million masks delivered to Canada in May also failed to meet standards. [185] [186]

Theft

Thefts of face masks and other personal protective equipment have been reported at hospitals in the United States and other countries. [187]

The Naval Medical Center San Diego began mandatory random bag checks for staff members, after several incidents of theft. [188] 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. [189] Thefts of N95 masks were reported from a locked hospital office in South Carolina and off loading docks at the University of Washington. [190]

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. [191] A hospital employee in Cooperstown, New York was charged with misdemeanor larceny for a similar incident. [192] Hospital employees in West Java, Indonesia were arrested for stealing hundreds of boxes of face masks and selling them on the black market. [193]

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: [187]

"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. [194] 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. [195] 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. [196] [197]

According to a BBC News report from August 2020, hospital staff in Ghana were selling PPE on the black market. [198]

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. [199]

Destruction in wars

During the Tigray War that started in November 2020, looting of the means of survival led not only to emergency conditions of acute food insecurity but also to concerns about management of the COVID-19 pandemic. As of January 2021, only five out of forty hospitals were "physically accessible" and most hospitals outside of the Tigrayan capital Mekelle had been looted or destroyed. [200]

N95 and FFP masks

N95 and FFP masks were in short supply and high demand during the COVID-19 pandemic. [201] [176] 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. [47] [202] China controls fifty 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. [47]

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. [203] [204] White House trade adviser Peter Navarro said there were concerns that 3M products were not making their way to the US. [203] 3M replied that it has not changed the prices it charges, and was unable to control the prices its dealers or retailers charge. [203]

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 to the US. Moskowitz said 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). [205] [206] [207]

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. [208] [209]

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." [210] [211] 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. [210]

Trump gave Rear Admiral John Polowczyk the responsibility for the logistics of PPE. Polowczyk said 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." [210]

By February 2021, suppliers had increased production but not enough to meet demand. Companies cited concerns about post-pandemic demand as a reason for not entering the market. Hospitals increased supplies, but even at well-funded hospitals, healthcare workers could be expected to wear their masks for up to a month. Counterfeits continued to pose problems for purchasers. [212] Numerous calls by public health experts had been made to provide high-filtration masks such as N95s or their equivalents to the general public in high-risk settings. [213] [214]

Germany

In early April 2020, the Berlin politician Andreas Geisel alleged that a shipment of 200,000 N95 masks it had ordered from American producer 3M's China facility were intercepted in Bangkok, Thailand 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." The US government denied any confiscation and said they use appropriate channels for all their purchases. [215] [216] Berlin police later confirmed that the shipment was not seized by US authorities.[ citation needed ]

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. [217] 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." [218] The Guardian also reported that "There is no solid proof Trump [nor any other American official] approved the [German] heist." [219]

German citizens decided to contribute to solving the supply crisis by making their own masks and other types of PPE like face shields that gave masks additional protection; the largest group of makers measured 6,800 individuals, collectively producing more than 100,000 pieces of protective equipment. [220]

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. [221] 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. [222]

The mask industry

Manufacturing

Masks being produced in Taiwan 02.05 Zong Tong Fang Shi [Tai Wan Kang Jiang Zhi Zao Gong Si ]  (49491845167).jpg
Masks being produced in Taiwan

As of 2019, mainland China manufactured half the world output of masks. [223] As COVID-19 spread, enterprises in several countries quickly started or increased the production of face masks. [224] 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. [225] [226] [227] [228]

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. [229]

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. [229]

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. [230]

Between April and June 2020, sellers on Etsy sold 29 million cloth face masks worth an estimated $364 million. Approximately four million people (about seven percent of buyers) visited the website just to buy masks. [231]

Society and culture

Attitudes

In East Asian societies, a primary reason for mask-wearing is to protect others from oneself. [232] [233] The broad assumption behind the act is that anyone, including seemingly healthy people, can be a carrier of the coronavirus. [233] The usage of masks is seen as a collective responsibility to reduce the transmission of the virus. [234] A face mask is thus seen as a symbol of solidarity in Eastern countries. [234] Elsewhere, the need for mask-wearing is still often seen from an individual perspective where masks only serve to protect oneself. [232] In April 2020, a study comparing masking-related perceptions between China and three German speaking countries (Austria, Germany, and Switzerland) also showed that Chinese had stronger pro-masking perceptions than the European participants. [235] However, over the course of the pandemic, people began promoting a new meaning of masking as an act of solidarity to each other. [236] [237] [238] [239] Masking is gradually shifting to become a new social norm. [240] [241]

Slovakia was one of the first countries in the world to introduce universal masking in public places Koronavirus - Bratislavsky samospravny kraj (49677032937).jpg
Slovakia was one of the first countries in the world to introduce universal masking in public places

Existing cultural norms and social pressure may impede mask-wearing in public, which explains why masking has been avoided in the West. [243] 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. [75] 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. [244]

Helene-Mari van der Westhuizen et al. point out that successful implementation of public masking policies, especially in communities that have 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. [245] 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 who do not mask as deviant. [245] 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. [245] 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. [246] 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. [246]

In the Western world, the public usage of masks still often carries a large stigma, [232] [234] [247] as it is seen as a sign of sickness. [247] 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. [248] 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. [232] [ needs update ]

Mask-wearing has been called a prosocial behavior in which one protects others within their community. [249] [250] [251] On social media, there has been an effort with the #masks4all campaign to encourage people to use masks. [252] 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. [253] [254] [255] [256] Multiple people have been killed in attacks by people who refused to mask. [257] 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. [258]

Masking has been subjected to racial politics in Western countries. [259] For instance, it has been heavily racialized as an Asian phenomenon. [234] [246] 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. [259] [260] 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. [259] [261] Huang Yinxiang, a sociologist from the University of Manchester, described maskaphobia (negative prejudice, fear or bitter 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. [262] 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. [263] [264] [265]

A sign language interpreter (on the right) in Hong Kong is wearing a transparent mask to allow lip reading Hospital Authority staff strike during the COVID-19, transparent surgical mask.jpg
A sign language interpreter (on the right) in Hong Kong is wearing a transparent mask to allow lip reading

There have also been concerns that wearing 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. [266] [267] This led to calls for wider distributions of transparent masks, which allow for lip reading. [266] [267] 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. [268] 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. [269] For instance, in the United Kingdom, the charity Disability Rights UK received numerous reports about people being confronted on trains and buses. [269] 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. [270] [271] However, anti-maskers have called upon bogus claims about legal or medical exemptions in their refusal to mask. [270] 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 that the act "does not provide a blanket exemption to people with disabilities from complying with legitimate safety requirements necessary for safe operations". [272]

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. [273]

A mask compliance officer at a baseball park in Florida, United States of America Mask compliance officer.jpg
A mask compliance officer at a baseball park in Florida, United States of America

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. [274] 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. [274] An exception was the United Kingdom where mask usage only grew gradually during this time, [274] but it rose very quickly after official policy changes in July mandated masking in stores. [275]

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. [276] Furthermore, people who did not report mask use also reported engaging in significantly fewer other mitigation behaviors than those who did report mask use. [276]

Gender plays a role in the willingness to wear masks during the pandemic; men are overall less inclined to mask in public than women. [277] [278] [279] There are indications that men are more likely to feel negative emotions (such as shame) and stigma for wearing masks. [277] [278] 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. [280] [281] 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. [282]

Governmental role

The heads of state and government of Portugal and Spain wearing face masks during an official ceremony in July 2020 La reapertura de la frontera entre Espana y Portugal, Badajoz y Elvas, miercoles 1 de julio de 2020 (10).png
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. [251]

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. [251] However, it also suggests that voluntary policies have the potential effect to increase polarization and thus cause more stigmatization. [251] 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. [251]

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. [283] [284] 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. [285] 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. [286] [287] They have often been criticized for undercutting national and local public health advice to wear masks. [288] [289]

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 White House Coronavirus Update Briefing (49810101702).jpg
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

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. [291] 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. [292] [293] [294] 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. [294] [295] [296] [297] 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. [298] [299] [300] [301] [302] [ excessive citations ]

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. [303] Some people may see it as a political statement. [304] Party affiliation partly determined how likely people were to embrace the wearing of masks in public. [304] [305] Democrats were more likely to wear masks than Republicans. [304] [305] Masks have become an aspect of the culture war that has emerged over the course of the pandemic. [303] [304] [305] Commentators argue that the resistance against masks partly stems from the confusing and mixed messaging about masking. [303] [306] [307]

Matthew Facciani, a sociologist at Vanderbilt University, says 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. [308] 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. [308] Moreover, how people observe the masking rules seems to be different across countries and these differences may be attributed to cultural or management factors. [235]

In April 2020, health officials from Taiwan's Central Epidemic Command Center (CECC) pushed back on school bullying of boys in pink face masks. [309] 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. [309] 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." [309] 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. [309]

Opposition

In some countries, large rallies have taken place in protest against masking mandates. [310] [311] [312] In Canada, the anti-mask crowd has hailed their protests as the so-called "March to Unmask". [312] [313] In the United Kingdom, new protests came in the wake of the official announcement that masking will be compulsory in shops. [310] After eight months since the beginning of the lockdown in the Czech Republic, mass manifestations against the restrictions imposed by the government arose. [314] [315] Some anti-mask protestors have co-opted the feminist slogan "my body, my choice" [316] [317] [318] and the Black Lives Matter slogan "I can't breathe". [319] [320] Businesses have also been purposely disrupted by anti-maskers (purportedly in defense of their constitutional rights). [321]

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: First, 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. Second is a sense of invulnerability, as some people and especially younger individuals believe nothing bad will happen to them and are thus prone to risk-taking behaviors. Third, behavioral drift is seen among some people who find it difficult to maintain behaviors intended for prevention rather than treatment. Fourth, some people may have issues related to authority due to mistrust of science or tribe identification with powerful figures. Fifth, the act of covering one's face has an association with "bad", such as criminals or as an intention to hide something one is ashamed of. Sixth, 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 they do not want to do. [322]

In the United States, opposition to mask-wearing during the COVID-19 pandemic came during then-President Donald Trump's politicization of science [323] and more generally during decades-old period of politicization of science. American opposition to mask-wearing during pandemics is not new; during the 1918 influenza pandemic, the Anti-Mask League was established in San Francisco, California. [324]

In May 2021, Vice reported that some members of the anti-vaccine community were, ironically, promoting the use of masks and social distancing to protect themselves from those who have received vaccines, citing false claims that those vaccinated for COVID-19 "shed" spike proteins that can be harmful to people in their proximity, and discredited research scientist Judy Mikovits claimed that she had been kicked off a plane for wearing a mask lined with colloidal silver. [325]

Religion

Christian clergy from the Lutheran, Catholic, Presbyterian, Anglican, Baptist and Latter-day Saint traditions, as well as those from the Jewish, Buddhist and Unitarian religions have implored people to wear masks. [326]

Fashion

Cloth face mask in a style that matches the wearer's outfit Face mask for style and function during the COVID-19.jpg
Cloth face mask in a style that matches the wearer's outfit

As the pandemic progressed people began making use of face masks as accessories, [327] [328] [329] [330] matching them to their outfits and so on. [331] [332] 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. [333] These masks were sheerly utilitarian as the only consideration at the time was function. [334] What began as a public health necessity however gradually evolved into a new category of accessories subject to similar design and marketing considerations as other accessories. [335] 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. [328] Smaller brands, who primarily sold their products online, found that selling masks was a good strategy to maintain sales. [336] Etsy became a major online platform where many designers sold their masks. [336] Designers started making masks that matched other pieces of clothing and accessories, [337] [338] a trend which may have begun unintentionally as even fabric remnants were repurposed. [338]

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. [339]

The Walt Disney Company introduced uniform face masks for their employees at Walt Disney World and Disneyland in the United States. [340] [341]

Environment

Large numbers of disposed face masks have led to an increase in plastic waste, negatively impacting the environment. [342] [343] [344] Moreover, the production of face masks also contributes the emission of carbon dioxide, which accelerates global warming. [345]

Linguistic aspects

Due to the rarity of their use in non-medical settings outside East Asia, many languages lacked commonly used terms for facemasks, especially since legal issues prevent the usage of terms which might imply medical standards the masks do not meet. [346] In languages such as Saterfrisian public competitions were held [347] to create a neologism for the device in the language and thus not having to rely on loanwords or calques. [348] [349] The Friisk Foriining  [ frr ] held a similar competition for the North Frisian language. [350] [351]

Comparison by countries and territories

Face mask laws around the world as of 19 December 2020 Mask laws around the world.svg
Face mask laws around the world as of 19 December 2020
% of population wearing face masks in public, by country/territory (as of 9 August 2020) [352]
Country/territory%
Flag of Singapore.svg Singapore 92
Flag of Spain.svg Spain 90
Flag of Thailand.svg Thailand 88
Flag of Hong Kong.svg Hong Kong 86
Flag of Japan.svg Japan 86
Flag of Malaysia.svg Malaysia 85
Flag of Indonesia.svg Indonesia 85
Flag of the Philippines.svg Philippines 84
Flag of France.svg France 83
Flag of India.svg India 82
Flag of Italy.svg Italy 81
Flag of the People's Republic of China.svg China 80
Flag of the Republic of China.svg Taiwan 80
Flag of Vietnam.svg Vietnam 79
Flag of the United Arab Emirates.svg United Arab Emirates 79
Flag of the United Kingdom.svg United Kingdom 75
Flag of the United States.svg United States 75
Flag of Canada (Pantone).svg Canada 74
Flag of Saudi Arabia.svg Saudi Arabia 71
Flag of Mexico.svg Mexico 67
Flag of Germany.svg Germany 65
Flag of Australia (converted).svg Australia 41
Flag of Poland.svg Poland 23
Flag of Greece.svg Greece 19
Flag of Russia.svg Russia 10
Flag of Egypt.svg Egypt 8
Flag of Finland.svg Finland 7
Flag of Sweden.svg Sweden 6
Flag of Norway.svg Norway 5
Flag of Denmark.svg Denmark 4

See also

Related Research Articles

Personal protective equipment Equipment designed to help protect an individual from hazards

Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemicals, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. Protective clothing is applied to traditional categories of clothing, and protective gear applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit.

Surgical mask Mouth and nose cover against bacterial aerosols

A surgical mask, also known as a medical face mask, is a personal protective equipment worn by health professionals during medical procedures. When worn correctly, it prevents airborne transmission of infections between patients and/or treating personnel by blocking the movement of pathogens shed in respiratory droplets and aerosols from the wearer's mouth and nose.

Respirator Device worn to protect the user from inhaling contaminants

A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres, including fumes, vapours, gases and particulate matter such as dusts and airborne microorganisms. There are two main categories: the air-purifying respirator, in which respirable air is obtained by filtering a contaminated atmosphere, and the air-supplied respirator, in which an alternate supply of breathable air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants.

A breathing mask is a mask that covers the mouth, and usually other parts of the face or head, designed to direct the wearer's breath to and/or from a particular apparatus. It may mean, or be part of, one of these:

Isolation (health care) Measure taken to prevent contagious diseases from being spread

In health care facilities, isolation represents one of several measures that can be taken to implement in infection control: the prevention of communicable diseases from being transmitted from a patient to other patients, health care workers, and visitors, or from outsiders to a particular patient. Various forms of isolation exist, in some of which contact procedures are modified, and others in which the patient is kept away from all other people. In a system devised, and periodically revised, by the U.S. Centers for Disease Control and Prevention (CDC), various levels of patient isolation comprise application of one or more formally described "precaution".

Airborne transmission Disease transmission by airborne particles

Airborne or aerosol transmission is transmission of an infectious disease through small particles suspended in the air. Infectious diseases capable of airborne transmission include many of considerable importance both in human and veterinary medicine. The relevant infectious agent may be viruses, bacteria, or fungi, and they may be spread through breathing, talking, coughing, sneezing, raising of dust, spraying of liquids, flushing toilets, or any activities which generate aerosol particles or droplets.

COVID-19 Contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease has since spread worldwide, leading to an ongoing pandemic.

N95 respirator Particulate respirator meeting the N95 standard

An N95 filtering facepiece respirator, commonly abbreviated N95 respirator, is a particulate-filtering facepiece respirator that meets the U.S. National Institute for Occupational Safety and Health (NIOSH) N95 classification of air filtration, meaning that it filters at least 95% of airborne particles. This standard does not require that the respirator be resistant to oil; another standard, P95, adds that requirement. The N95 type is the most common particulate-filtering facepiece respirator. It is an example of a mechanical filter respirator, which provides protection against particulates but not against gases or vapors. An authentic N95 respirator is marked with the text "NIOSH" or the NIOSH logo, the filter class ("N95"), a "TC" approval number of the form XXX-XXXX, the approval number must be listed on the NIOSH Certified Equipment List (CEL) or the NIOSH Trusted-Source page, and it must have headbands instead of ear loops.

Workplace hazard controls for COVID-19 Prevention measures for COVID-19

Hazard controls for COVID-19 in workplaces are the application of occupational safety and health methodologies for hazard controls to the prevention of coronavirus disease 2019 (COVID-19). Vaccination is the most effective way to protect against severe illness or death from COVID-19. Multiple layers of controls are recommended, including measures such as telework and flexible schedules, increased ventilation, personal protective equipment (PPE) and face coverings, physical distancing, and enhanced cleaning programs.

Impact of the COVID-19 pandemic on public transport Effects of COVID-19 viral outbreak on public transport

The COVID-19 pandemic had a large impact on public transport. Many countries advised that public transport should only be used when essential; passenger numbers fell drastically, and services were reduced. Provision of a reasonable service for the much smaller number of fare-paying passengers incurred large financial losses.

Cloth face mask mask made of common textiles worn over the mouth and nose

A cloth face mask is a mask made of common textiles, usually cotton, worn over the mouth and nose. When more effective masks are not available, and when physical distancing is impossible, cloth face masks are recommended by public health agencies for disease "source control" in epidemic situations to protect others from virus laden droplets in infected mask wearers' breath, coughs, and sneezes. Because they are less effective than N95 masks, surgical masks, or physical distancing in protecting the wearer against viruses, they are not considered to be personal protective equipment by public health agencies. They are used by the general public in household and community settings as protection against both infectious diseases and particulate air pollution.

Mechanical filter (respirator) Air-filtering face masks or mask attachments

Mechanical filters are a class of filter for air-purifying respirators that mechanically stops particulates from reaching the wearer's nose and mouth. They come in multiple physical forms.

In epidemiology, a non-pharmaceutical intervention (NPI) is any method to reduce the spread of an epidemic disease without requiring pharmaceutical drug treatments. Examples of non-pharmaceutical interventions that reduce the spread of infectious diseases include wearing a face mask and staying away from sick people.

Source control (respiratory disease) Strategy for reducing disease transmission

Source control is a strategy for reducing disease transmission by blocking respiratory secretions produced through speaking, coughing, sneezing or singing. Surgical masks are commonly used for this purpose, with cloth face masks recommended for use by the public only in epidemic situations when there are shortages of surgical masks. In addition, respiratory etiquette such as covering the mouth and nose with a tissue when coughing can be considered source control. In diseases transmitted by droplets or aerosols, understanding air flow, particle and aerosol transport may lead to rational infrastructural source control measures that minimize exposure of susceptible persons.

Face masks during the COVID-19 pandemic in the United States Use of face coverings during the Coronavirus pandemic in the United States

The wearing of non-medical face masks in public to lessen transmission of COVID-19 in the United States was first recommended by the CDC on April 3, 2020 as supplemental to hygiene and appropriate social distancing. Over the course of the pandemic, various states, counties, and municipalities have issued health orders requiring the wearing of non-medical face coverings — such as cloth masks — in spaces and/or businesses accessible to the public, especially when physical distancing is not possible. Some areas only mandated their use by public-facing employees of businesses at first, before extending them to the general public.

Transmission of COVID-19 Mechanisms that spread coronavirus disease 2019

The transmission of COVID-19 is the passing of coronavirus disease 2019 from person to person. The disease is mainly transmitted via the respiratory route when people inhale droplets and small airborne particles that infected people exhale as they breathe, talk, cough, sneeze, or sing. Infected people are more likely to transmit COVID-19 when they are physically close. However, infection can occur over longer distances, particularly indoors.

Elastomeric respirator Respirator with a rubber face seal

Elastomeric respirators, also called reusable air-purifying respirators, are a type of respirator that seals to the face using a mask made of an elastomeric material, which may be a natural or synthetic rubber. They are generally reusable. Full-face versions of elastomeric respirators seal better and protect the eyes.

Maskne is a portmanteau of "mask" and "acne." The term appeared in use during the COVID-19 pandemic in 2020 to refer to acne and other rashes of the face that occur in association with mask wearing. The findings are observational only and related to pressure, occlusion and friction. It is likely that several are perioral dermatitis, rosacea, seborrheic dermatitis, folliculitis, irritant contact dermatitis or allergic contact dermatitis, and acne mechanica. In one article, maskne is observed to be caused by increase of humidity in the occluded area and sebum being secreted, increasing the amount of squalene on the skin. This, along with excess sweating lead to the swelling of epidermal keratinocytes, causing acute obstruction and acne aggravation. The hot and humid environment in which maskne is induced is also apparent with tropical acne.

United States responses to the COVID-19 pandemic Actions by the United States regarding the COVID-19 pandemic

The United States' response to the COVID-19 pandemic with consists of various measures by the medical community; the federal, state, and local governments; the military; and the private sector. The public response has been highly polarized, with partisan divides being observed and a number of concurrent protests and unrest complicating the response.

Mask refusal Refusal to wear face masks

Mask refusal is when a person refuses to comply with a requirement to wear a face covering, and does not meet the criteria for any exceptions to the requirement. This can occur during a pandemic when health experts recommend wearing face coverings in order to reduce the spread of disease, causing establishments or governments to require such wearing to protect the health of others.

References

  1. Knot and tuck technique: Modification to ear loop masks where the top and bottom of the ear loop string are knotted together at the mask's edges and extra material is tucked in towards the face. [41]
  1. 1 2 Bourouiba, Lydia (13 July 2021). "Fluid Dynamics of Respiratory Infectious Diseases". Annual Review of Biomedical Engineering. 23 (1): 547–577. doi:10.1146/annurev-bioeng-111820-025044. hdl: 1721.1/131115 . PMID   34255991. S2CID   235823756 . Retrieved 7 September 2021.
  2. "What Dr. Fauci wants you to know about face masks and staying home as virus spreads". PBS NewsHour. 3 April 2020. Retrieved 1 May 2021.
  3. Health, Center for Devices and Radiological (15 September 2021). "N95 Respirators, Surgical Masks, Face Masks, and Barrier Face Coverings". FDA.
  4. CDC (11 February 2020). "Considerations for Wearing Masks". Centers for Disease Control and Prevention. Retrieved 25 January 2021.
  5. "Personal Protective Equipments (PPE) -Prerequisites, Rationale and Challenges during COVID 19 Pandemic". ResearchGate. Retrieved 17 February 2021.
  6. Lam, Simon Ching; Suen, Lorna Kwai Ping; Cheung, Teris Cheuk Chi (May 2020). "Global risk to the community and clinical setting: Flocking of fake masks and protective gears during the COVID-19 pandemic". American Journal of Infection Control. 48 (8): 964–965. doi:10.1016/j.ajic.2020.05.008. PMC   7219383 . PMID   32405127.
  7. 1 2 Theresa Tam offers new advice: Wear a non-medical face mask when shopping or using public transit, The Globe and Mail, 6 April 2020.
  8. 1 2 "Coronavirus Disease 2019 (COVID-19)". Centers for Disease Control and Prevention. 11 February 2020. Retrieved 9 April 2020.
  9. 1 2 3 4 5 6 7 8 Godoy, Laura R. Garcia; Jones, Amy E.; Anderson, Taylor N.; Fisher, Cameron L.; Seeley, Kylie M. L.; Beeson, Erynn A.; Zane, Hannah K.; Peterson, Jaime W.; Sullivan, Peter D. (5 May 2020). "Facial protection for healthcare workers during pandemics: a scoping review". BMJ Global Health. 5 (5): e002553. doi:10.1136/bmjgh-2020-002553. ISSN   2059-7908. PMC   7228486 . PMID   32371574.
  10. Konda A, Prakash A, Guha S (2020). "Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks". ACS Nano . 14 (5): 6339–6347. doi:10.1021/acsnano.0c03252. PMC   7185834 . PMID   32329337.
  11. Daoud, Ariel Kiyomi; Hall, Jessica Kole; Petrick, Haylie; Strong, Anne; Piggott, Cleveland (1 January 2021). "The Potential for Cloth Masks to Protect Health Care Clinicians From SARS-CoV-2: A Rapid Review". The Annals of Family Medicine. 19 (1): 55–62. doi: 10.1370/afm.2640 . ISSN   1544-1709. PMC   7800735 . PMID   33431393.
  12. Davies, Anna; Thompson, Katy-Anne; Giri, Karthika; Kafatos, George; Walker, Jimmy; Bennett, Allan (22 May 2013). "Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?". Disaster Medicine and Public Health Preparedness. 7 (4): 413–418. doi:10.1017/dmp.2013.43. ISSN   1935-7893. PMC   7108646 . PMID   24229526.
  13. Aydin O, Emon B, Cheng S, Saif A (2020). "Performance of fabrics for home-made masks against the spread of COVID-19 through droplets: A quantitative mechanistic study". Extreme Mechanics Letters . 40: 100924. doi:10.1016/j.eml.2020.100924. PMC   7417273 . PMID   32835043.
  14. 1 2 3 4 5 "Coronavirus disease (COVID-19) advice for the public: When and how to use masks". World Health Organization. 20 October 2020. Archived from the original on 29 October 2020.
  15. 1 2 Clase CM, Fu EL, Ashur A, Carrero JJ (2020). "Forgotten Technology in the COVID-19 Pandemic: Filtration Properties of Cloth and Cloth Masks-A Narrative Review". Mayo Clinic Proceedings . 95 (10): 2204–2224. doi: 10.1016/j.mayocp.2020.07.020 . PMC   7834536 . PMID   33012350.
  16. "Plain language Mayo Clin Proc 2020".
  17. "How to Make a Cloth Mask".
  18. "Topics".
  19. "How to Put on a Cloth Mask".
  20. "How to Take off a Cloth Mask".
  21. "How to Clean a Cloth Mask".
  22. "Frequent Questions About Hand Hygiene: Handwashing". www.cdc.gov. 14 October 2020. Retrieved 7 November 2020.
  23. "How to Safely Wear and Take Off a Cloth Face Covering" (PDF). CDC.
  24. "Does a PM 2.5 filter help with coronavirus? - UAB Medicine News - UAB Medicine". www.uabmedicine.org. Retrieved 7 November 2020.
  25. 1 2 3 "N95 Respirators and Surgical Masks (Face Masks)". U.S. Food and Drug Administration. 11 March 2020. Retrieved 28 March 2020.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  26. Wei, Neo Kang (6 May 2019). "What is PM0.3 and Why Is It Important?". Smart Air Filters.
  27. US 5496507,"Method Of Charging Electret Filter Media"
  28. "Properties of Different Types of Masks" (PDF). Government of New South Wales Clinical Excellence Commission. February 2020. Archived from the original (PDF) on 31 March 2020.
  29. Jung, James (17 March 2020). "KAIST Researchers Develop Highly Reusable Mask Filter". KoreaTechToday.
  30. 1 2 3 "Recommended Guidance for Extended Use and Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings". cdc.gov. NIOSH Workplace Safety and Health Topic. CDC. 27 March 2020.
  31. 1 2 "Coronavirus Disease 2019 (COVID-19)". Centers for Disease Control and Prevention. 11 February 2020.
  32. "Not Enough Face Masks Are Made In America To Deal With Coronavirus". NPR. 5 March 2020. Retrieved 10 April 2020.
  33. "Chinese mask makers use loopholes to speed up regulatory approval". Financial Times. 1 April 2020. Retrieved 10 April 2020.
  34. Long, Y; Hu, T; Liu, L; Chen, R; Guo, Q; Yang, L; Cheng, Y; Huang, J; Du, L (13 March 2020). "Effectiveness of N95 respirators versus surgical masks against influenza: A systematic review and meta-analysis". Journal of Evidence-Based Medicine. 13 (2): 93–101. doi:10.1111/jebm.12381. PMC   7228345 . PMID   32167245.
  35. Zangmeister, Christopher D.; Radney, James G.; Vicenzi, Edward P.; Weaver, Jamie L. (28 July 2020). "Filtration Efficiencies of Nanoscale Aerosol by Cloth Mask Materials Used to Slow the Spread of SARS-CoV-2". ACS Nano. 14 (7): 9188–9200. doi:10.1021/acsnano.0c05025. ISSN   1936-0851. PMC   7341689 . PMID   32584542.
  36. Gawn, Jonathan (2008). "Evaluating the protection afforded by surgical masks against influenza bioaerosols" (PDF). UK's Health and Safety Executive.
  37. Robertson, Paddy (15 March 2020). "Comparison of Mask Standards, Ratings, and Filtration Effectiveness". Smart Air Filters.
  38. 中华人民共和国医药行业标准:YY 0469–2011 医用外科口罩(Surgical mask) (in Chinese)
  39. 中华人民共和国医药行业标准:YY/T 0969–2013 一次性使用医用口罩(Single-use medical face mask) (in Chinese)
  40. Mueller, Amy V.; Eden, Matthew J.; Oakes, Jessica M.; Bellini, Chiara; Fernandez, Loretta A. (2 September 2020). "Quantitative Method for Comparative Assessment of Particle Removal Efficiency of Fabric Masks as Alternatives to Standard Surgical Masks for PPE". Matter. 3 (3): 950–962. doi:10.1016/j.matt.2020.07.006. ISSN   2590-2393. PMC   7346791 . PMID   32838296.
  41. 1 2 Clapp, Phillip W.; Sickbert-Bennett, Emily E.; Samet, James M.; Berntsen, Jon; Zeman, Kirby L.; Anderson, Deverick J.; Weber, David J.; Bennett, William D. (10 December 2020). "Evaluation of Cloth Masks and Modified Procedure Masks as Personal Protective Equipment for the Public During the COVID-19 Pandemic". JAMA Internal Medicine. 181 (4): 463–469. doi: 10.1001/jamainternmed.2020.8168 . ISSN   2168-6106. PMC  7729588. PMID   33300948.
  42. Brooks, John T. (2021). "Maximizing Fit for Cloth and Medical Procedure Masks to Improve Performance and Reduce SARS-CoV-2 Transmission and Exposure, 2021". MMWR. Morbidity and Mortality Weekly Report. 70 (7): 254–257. doi: 10.15585/mmwr.mm7007e1 . ISSN   0149-2195. PMC   7891692 . PMID   33600386.
  43. Cavalcanti, Gui; Cocciole, Claire; Cole, Christina; Forgues, Angela; Jaqua, Victoria; Jones-Davis, Dorothy; Merlo, Sabrina (2021). Design, Make, Protect: A report on the Open Source Maker and Manufacturer Response to the COVID-19 PPE Crisis (PDF). Open Source Medical Supplies & Nation of Makers. pp. 22, 46. Retrieved 17 June 2021.
  44. "NIOSH-Approved N95 Particulate Filtering Facepiece Respirators – A Suppliers List". U.S. National Institute for Occupational Safety and Health. 19 March 2020. Retrieved 27 March 2020.
  45. "Respirator Trusted-Source: Selection FAQs". U.S. National Institute for Occupational Safety and Health. 12 March 2020. Retrieved 28 March 2020.
  46. Naveed, Hasan; Scantling-Birch, Yarrow; Lee, Hanbin; Nanavaty, Mayank A. (2 April 2020). "Controversies regarding mask usage in ophthalmic units in the United Kingdom during the COVID-19 pandemic". Eye. 34 (7): 1172–1174. doi: 10.1038/s41433-020-0892-2 . ISSN   1476-5454. PMC   7179380 . PMID   32327740.
  47. 1 2 3 Zie, John (19 March 2020). "World Depends on China for Face Masks But Can Country Deliver?". Voice of America.
  48. Feng, Emily (16 March 2020). "COVID-19 Has Caused A Shortage Of Face Masks. But They're Surprisingly Hard To Make". NPR.
  49. "Comparison of FFP2, KN95, and N95 and Other Filtering Facepiece Respirator Classes" (PDF). 3M Technical Data Bulletin. 1 January 2020. Retrieved 28 March 2020.
  50. "Strategies for Optimizing the Supply of N95 Respirators: Crisis/Alternate Strategies". U.S. Centers for Disease Control and Prevention. 17 March 2020. Retrieved 28 March 2020.
  51. 1 2 Patel, Rajeev B.; Skaria, Shaji D.; Mansour, Mohamed M.; Smaldone, Gerald C. (28 April 2016). "Respiratory source control using a surgical mask: An invitro study". Journal of Occupational and Environmental Hygiene. 13 (7): 569–576. doi:10.1080/15459624.2015.1043050. ISSN   1545-9624. PMC   4873718 . PMID   26225807.
  52. "Interim Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19) in Healthcare Settings". Centers for Disease Control and Prevention (CDC). 18 May 2020. Retrieved 8 June 2020.
  53. Mills, Stu (10 April 2020). "Researchers looking at innovative ways to sterilize single-use masks". Canadian Broadcasting Corporation.
  54. 1 2 3 "Considerations for Wearing Masks". Centers for Disease Control and Prevention. 7 August 2020. Archived from the original on 7 August 2020.
  55. Lindsley, William G.; Blachere, Francoise M.; Law, Brandon F.; Beezhold, Donald H.; Noti, John D. (7 January 2021). "Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols". Aerosol Science and Technology. 55 (4): 449–457. Bibcode:2021AerST..55..449L. doi: 10.1080/02786826.2020.1862409 .
  56. Lindsley, William G.; Noti, John D.; Blachere, Francoise M.; Szalajda, Jonathan V.; Beezhold, Donald H. (3 August 2014). "Efficacy of Face Shields Against Cough Aerosol Droplets from a Cough Simulator". Journal of Occupational and Environmental Hygiene. 11 (8): 509–518. doi:10.1080/15459624.2013.877591. PMC   4734356 . PMID   24467190. Cited in Garcia Godoy, Laura R; Jones, Amy E; Anderson, Taylor N; Fisher, Cameron L; Seeley, Kylie M L; Beeson, Erynn A; Zane, Hannah K; Peterson, Jaime W; Sullivan, Peter D (5 May 2020). "Facial protection for healthcare workers during pandemics: a scoping review". BMJ Global Health. 5 (5): e002553. doi: 10.1136/bmjgh-2020-002553 . PMC   7228486 . PMID   32371574.
  57. 1 2 3 Chu, Derek K; Akl, Elie A; Duda, Stephanie; Solo, Karla; Yaacoub, Sally; Schünemann, Holger J; et al. (27 June 2020). "Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis". The Lancet. 395 (10242): 1973–1987. doi: 10.1016/S0140-6736(20)31142-9 . PMC   7263814 . PMID   32497510.
  58. 1 2 3 "Elastomeric Respirators: Strategies During Conventional and Surge Demand Situations". Centers for Disease Control and Prevention. 13 October 2020. Archived from the original on 16 October 2020.
  59. 1 2 Chiang, James; Hanna, Andrew; Lebowitz, David; Ganti, Latha (December 2020). "Elastomeric respirators are safer and more sustainable alternatives to disposable N95 masks during the coronavirus outbreak". International Journal of Emergency Medicine. 13 (1): 39. doi: 10.1186/s12245-020-00296-8 . PMC   7369563 . PMID   32689926.
  60. 1 2 Howard, Brittany E. (July 2020). "High-Risk Aerosol-Generating Procedures in COVID-19: Respiratory Protective Equipment Considerations". Otolaryngology–Head and Neck Surgery. 163 (1): 98–103. doi: 10.1177/0194599820927335 . PMID   32396451.
  61. Mick, Paul; Murphy, Russell (December 2020). "Aerosol-generating otolaryngology procedures and the need for enhanced PPE during the COVID-19 pandemic: a literature review". Journal of Otolaryngology - Head & Neck Surgery. 49 (1): 29. doi: 10.1186/s40463-020-00424-7 . PMC   7212733 . PMID   32393346.
  62. Licina, Ana; Silvers, Andrew; Stuart, Rhonda L. (8 August 2020). "Use of powered air-purifying respirator (PAPR) by healthcare workers for preventing highly infectious viral diseases – a systematic review of evidence". Systematic Reviews. 9 (1): 173. doi: 10.1186/s13643-020-01431-5 . PMC   7414632 . PMID   32771035.
  63. Staymates, Matthew (1 November 2020). "Flow visualization of an N95 respirator with and without an exhalation valve using schlieren imaging and light scattering". Physics of Fluids . 32 (11): 111703. Bibcode:2020PhFl...32k1703S. doi:10.1063/5.0031996. ISSN   1070-6631. PMC   7684679 . PMID   33244212. CC-BY icon.svg Available under CC BY 4.0.
  64. "Filtering Facepiece Respirators with an Exhalation Valve: Measurements of Filtration Efficiency to Evaluate Their Potential for Source Control". NIOSH Publications. 9 December 2020. doi: 10.26616/NIOSHPUB2021107 .
  65. "Face shields, masks with valves ineffective against COVID-19 spread: study". phys.org. Retrieved 8 October 2020.
  66. Verma, Siddhartha; Dhanak, Manhar; Frankenfield, John (1 September 2020). "Visualizing droplet dispersal for face shields and masks with exhalation valves". Physics of Fluids. 32 (9): 091701. arXiv: 2008.00125 . Bibcode:2020PhFl...32i1701V. doi: 10.1063/5.0022968 . ISSN   1070-6631. PMC   7497716 . PMID   32952381.
  67. 1 2 3 "Using face masks in the community - Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks". European Centre for Disease Prevention and Control. 8 April 2020. Archived from the original on 8 April 2020.
  68. 1 2 3 4 "Advice on the use of masks in the context of COVID-19". World Health Organization. 5 June 2020.
  69. Ting, Victor (4 April 2020). "To mask or not to mask: WHO makes U-turn while US, Singapore abandon pandemic advice and tell citizens to start wearing masks". South China Morning Post .
  70. "Cloth masks can help stop the spread of COVID-19, save lives and restore jobs". #Masks4All. Archived from the original on 25 September 2020. Retrieved 27 September 2020. The leading disease experts and governments representing 95% of the world's population (including the U.S. CDC) agree with the science and require/recommend masks because cloth (non-medical) masks are shown to limit the spread of COVID-19.
  71. Advice on the use of masks in the community, during home care and in health care settings in the context of the novel coronavirus (2019-nCoV) outbreak: interim guidance, 29 January 2020 (Report). World Health Organization. 29 January 2020. hdl:10665/330987.
  72. Advice on the use of masks in the community, during home care, and in health care settings in the context of COVID-19: interim guidance, 19 March 2020 (Report). World Health Organization. 19 March 2020. hdl:10665/331493.
  73. 1 2 Advice on the use of masks in the context of COVID-19: interim guidance, 6 April 2020 (Report). World Health Organization. 6 April 2020. hdl:10665/331693.
  74. Keshtkar-Jahromi, Maryam; Sulkowski, Mark; Holakouie-Naieni, Kourosh (3 June 2020). "Public Masking: An Urgent Need to Revise Global Policies to Protect against COVID-19". The American Journal of Tropical Medicine and Hygiene. 102 (6): 1160–1161. doi: 10.4269/ajtmh.20-0305 . PMC   7253086 . PMID   32323645.
  75. 1 2 3 Winn, Patrick (1 April 2020). "Will the US ever mimic Asia's culture of 'universal masking'?". Public Radio International.
  76. 1 2 3 Tufekci, Zeynep (17 March 2020). "Why Telling People They Don't Need Masks Backfired". The New York Times . Retrieved 12 April 2020.
  77. Feng, Shuo; Shen, Chen; Xia, Nan; Song, Wei; Fan, Mengzhen; Cowling, Benjamin J (May 2020). "Rational use of face masks in the COVID-19 pandemic". The Lancet Respiratory Medicine. 8 (5): 434–436. doi: 10.1016/S2213-2600(20)30134-X . PMC   7118603 . PMID   32203710.
  78. Flaskerud, Jacquelyn H. (1 September 2020). "Masks, Politics, Culture and Health". Issues in Mental Health Nursing. 41 (9): 846–849. doi: 10.1080/01612840.2020.1779883 . PMID   32644832.
  79. Mantzari, Eleni; Rubin, G James; Marteau, Theresa M (26 July 2020). "Is risk compensation threatening public health in the covid-19 pandemic?". BMJ. 370: m2913. doi: 10.1136/bmj.m2913 . PMID   32713835.
  80. Hunt, Katie (27 July 2020). "Face mask wearers don't get lax about washing hands, study suggests". CNN.
  81. Feuer, William; Higgins-Dunn, Noah (8 June 2020). "Asymptomatic spread of coronavirus is 'very rare', WHO says". CNBC.
  82. "Q&A: Masks and COVID-19". World Health Organization. 7 June 2020. Archived from the original on 27 July 2020. For more details on fabrics, see also "Advice on the use of masks in the context of COVID-19". World Health Organization. 5 June 2020.
  83. 1 2 3 4 "Advice on the use of masks for children in the community in the context of COVID-19". World Health Organization. 21 August 2020. For an overview, see "Q&A: Children and masks related to COVID-19". World Health Organization. 21 August 2020.
  84. "Q&A: Masks and COVID-19". World Health Organization. 7 June 2020. Archived from the original on 27 July 2020.
  85. "Use of cloth face coverings to help slow the spread of COVID-19". Centers for Disease Control and Prevention. 3 April 2020.
  86. López, Canela. "Celebrities like Gwyneth Paltrow and Kate Hudson were criticized for wearing face masks early in the pandemic. Here's what changed". Business Insider.
  87. "Transcript for CDC Telebriefing: CDC Update on Novel Coronavirus". Centers for Disease Control and Prevention. 12 February 2020.
  88. "Fact check: Medical discharge document includes outdated CDC guidance on face masks". Reuters. 3 July 2020.
  89. Fisher, Kiva A.; Barile, John P.; Guerin, Rebecca J.; Vanden Esschert, Kayla L.; Jeffers, Alexiss; Tian, Lin H.; Garcia-Williams, Amanda; Gurbaxani, Brian; Thompson, William W.; Prue, Christine E. (17 July 2020). "Factors Associated with Cloth Face Covering Use Among Adults During the COVID-19 Pandemic – United States, April and May 2020". MMWR. Morbidity and Mortality Weekly Report. 69 (28): 933–937. doi: 10.15585/mmwr.mm6928e3 . PMID   32673303. S2CID   220606747.
  90. 1 2 Jingnan, Huo (10 April 2020). "Why There Are So Many Different Guidelines For Face Masks For The Public". NPR.
  91. Mills, Russell (29 July 2020). "CDC director: Face masks "our most powerful tool" to fight COVID-19". 102.3 KRMG.
  92. Brooks, John T.; Butler, Jay C.; Redfield, Robert R. (14 July 2020). "Universal Masking to Prevent SARS-CoV-2 Transmission – The Time Is Now". JAMA. 324 (7): 635–637. doi: 10.1001/jama.2020.13107 . PMC   8607819 . PMID   32663243.
  93. Henry, Tanya Albert (17 July 2020). "CDC's Dr. Redfield: This is why everyone should be wearing masks". American Medical Association.
  94. "Personal Protective Equipment: Questions and Answers". Centers for Disease Control and Prevention. 8 August 2020. Archived from the original on 10 August 2020.
  95. 1 2 "Considerations for wearing cloth face coverings : help slow the spread of COVID-19". Centers for Disease Control and Prevention. 28 June 2020.
  96. Miller, Sara G. (13 August 2020). "Does your mask have a valve on it? It won't stop the spread of coronavirus, CDC says". NBC News.
  97. 1 2 3 4 "Scientific Brief: Community Use of Cloth Masks to Control the Spread of SARS-CoV-2". Centers for Disease Control and Prevention. 10 November 2020.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  98. "Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic". Centers for Disease Control and Prevention. 15 July 2020. Archived from the original on 30 July 2020.
  99. "Strategies for Optimizing the Supply of N95 Respirators". Centers for Disease Control and Prevention. 28 June 2020. Archived from the original on 28 July 2020.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  100. "When You've Been Fully Vaccinated". Centers for Disease Control and Prevention. 27 July 2021. Archived from the original on 28 July 2021.
  101. Aubrey, Allison (27 July 2021). "CDC Urges Vaccinated People To Mask Up Indoors In Places With High Virus Transmission". NPR.
  102. "Interim Public Health Recommendations for Fully Vaccinated People". Centers for Disease Control and Prevention. 13 May 2021. Archived from the original on 14 May 2021.
  103. Noguchi, Yuki (20 May 2021). "The CDC Is Gambling On Relaxed Mask Rules To Get More People Vaccinated". NPR.
  104. Bosman, Julie; Mervosh, Sarah (18 May 2021). "New Honor System on Masks: 'Am I to Trust These People?'". The New York Times.
  105. Iati, Marisa (15 May 2021). "The new mask guidance relies on an honor system. Do we trust each other enough to make it work?". Washington Post.
  106. Wetsman, Nicole (3 April 2020). "Masks may be good, but the messaging around them has been very bad". The Verge.
  107. Jankowicz, Mia (1 June 2020). "Fauci said US government held off promoting face masks because it knew shortages were so bad that even doctors couldn't get enough". Business Insider .
  108. Cohen, Jon (27 March 2020). "Not wearing masks to protect against coronavirus is a 'big mistake'". Science.
  109. "Mandatory mask-wearing now the norm in Europe as COVID-19 cases rise". euronews. 24 July 2020.
  110. 1 2 "Norway Makes First Face Mask Recommendation Since Pandemic Began". VOA News. 14 August 2020.
  111. Vogel, Gretchen (6 October 2020). "'It's been so, so surreal.' Critics of Sweden's lax pandemic policies face fierce backlash". Science. doi:10.1126/science.abf1247. S2CID   225148153.
  112. "Using face masks in the community: first update - Effectiveness in reducing transmission of COVID-19". European Centre for Disease Prevention and Control. 15 February 2021. Archived from the original on 17 February 2021.
  113. "Hoe iets 'wat geen bescherming biedt' toch landelijk geadviseerd werd" [How something 'that offers no protection' was nevertheless advised nationally]. nos.nl (in Dutch). Retrieved 24 February 2021.
  114. "Face Masks to Be Compulsory on Public Transport in the Netherlands".
  115. "Why are the Nordic countries still not recommending face masks?". The Local dk. 30 July 2020.
  116. Stoltenberg, Camilla (June 2020), "Should individuals in the community without respiratory symptoms wear facemasks to reduce the spread of COVID-19? – a rapid review" (PDF), Norwegian Institute of Public Health
  117. "Denmark Recommends Face Masks On Public Transport". Barron's. 31 July 2020.
  118. "No country for face masks: Nordics brush off mouth covers". medicalxpress. 30 July 2020.
  119. 1 2 "The Copenhagen Post". 23 October 2020.
  120. "Norwegian municipalities introduce local coronavirus rules: Here's what applies in your area". 2 October 2020.
  121. "Tegnells vändning: Lämpligt med munskydd (om man är nära varandra)". Breakit (in Swedish). Retrieved 13 May 2021.
  122. Lönnroth, Valdemar (25 November 2020). "Tegnell: Då ska du bära munskydd på jobbet". gp.se (in Swedish). Retrieved 13 May 2021.
  123. "Sweden does U-turn on face masks to fight virus". France 24. 18 December 2020.
  124. "Munskydd i kollektivtrafiken från den 7 januari". Folkhalsomyndigheten. 30 December 2020.
  125. "Statsminister Löfven besökte galleria fyra dagar före jul".
  126. Nyheter, S. V. T.; Razooq, Nada (22 January 2021). "Hälften av resenärerna använder munskydd under rusningstid enligt SL". SVT Nyheter.
  127. Nyheter, S. V. T.; Pan, Ellen; Lindberg, Jasmin (28 January 2021). "FHM:s generaldirektör åkte kollektivtrafik utan munskydd: "Genant"". SVT Nyheter.
  128. "Nyheter24 avslöjar: Här åker Anders Tegnell tåg i rusningstrafik – utan munskydd". 4 February 2021.
  129. Tang, Julian W.; Nicolle, Andre D. G.; Pantelic, Jovan; Jiang, Mingxiu; Sekhr, Chandra; Cheong, David K. W.; Tham, Kwok Wai (22 June 2011). "Qualitative Real-Time Schlieren and Shadowgraph Imaging of Human Exhaled Airflows: An Aid to Aerosol Infection Control". PLOS ONE. 6 (6): e21392. Bibcode:2011PLoSO...621392T. doi: 10.1371/journal.pone.0021392 . PMC   3120871 . PMID   21731730.
  130. Verma, Siddhartha; Dhanak, Manhar; Frankenfield, John (1 June 2020). "Visualizing the effectiveness of face masks in obstructing respiratory jets". Physics of Fluids. 32 (6): 061708. Bibcode:2020PhFl...32f1708V. doi: 10.1063/5.0016018 . PMC   7327717 . PMID   32624649.
  131. Prather, Kimberly A.; Wang, Chia C.; Schooley, Robert T. (26 June 2020). "Reducing transmission of SARS-CoV-2". Science. 368 (6498): 1422–1424. Bibcode:2020Sci...368.1422P. doi: 10.1126/science.abc6197 . PMID   32461212.
  132. 1 2 3 4 5 "Why healthy Chinese wearing face masks outdoors?". NHC.gov.cn. National Health Commission. 23 March 2020. Archived from the original on 10 April 2020. Retrieved 12 April 2020.
  133. Cheng, Kar Keung; Lam, Tai Hing; Leung, Chi Chiu (16 April 2020). "Wearing face masks in the community during the COVID-19 pandemic: altruism and solidarity". The Lancet: S0140673620309181. doi: 10.1016/S0140-6736(20)30918-1 . PMC   7162638 . PMID   32305074.
  134. 1 2