Why Are Masks Needed in Schools?
This page summarizes arguments and evidence for masks and mask mandates in schools. Last updated 2023-02-17.
You can download an editable template containing the information on this page, to facilitate submitting this evidence to a school board or similar body.
An opinion piece in The Conversation, co-authored by MaskEvidence team members, arguing for return to general mask mandates is here.
An opinion piece in The Hamilton Spectator, co-authored by MaskEvidence EiC, arguing for return to mask mandates in schools is here.
Is COVID a problem in schools?
Yes, COVID is in schools. Not all students who are symptomatic will stay home. Students with known COVID are expected to return to school once they are improving, while still potentially infectious. In some jurisdictions, for example, in Ontario and in Alberta, students whose symptoms are improving are supposed to wear a mask in all public indoor settings until day 10, but this may not be widely known and is unenforceable. After COVID, more than 25% of people are still infectious on days 7 to 9.
Some students may use rapid tests when symptomatic to help guide their actions. A positive rapid test is still a very useful sign of COVID, but a negative test does not rule it out: 63% of people with Omicron will have a negative rapid test, and 37% a positive test. A negative rapid test in a student with symptoms leads to a false sense of security.
So COVID is out there in classrooms.
In adults who were vaccinated and had COVID that wasn’t severe, 8% developed long COVID, which is defined as symptoms that persist more than 12 weeks.
Does COVID hurt children and adolescents? Isn’t it just a cold for them?
Two recent studies show that long COVID is also a serious problem in children.
Published in Nature, 29 November 2022, we now know that 4% of children infected with COVID will develop long COVID. Symptoms include trouble concentrating, headache, nausea, nervousness and fatigue. In other words, 1 in 25 students infected with COVID will suffer long-term consequences to their health, many of them specifically the kinds of problems that interfere with learning.
Published in PLOS One, 10 November 2022, the risk of malaise/fatigue/exhaustion was increased by 128% in children and adolescents who had had COVID, compared with those who had not. Adjustment disorder was increased by 71%, headache by 58%, anxiety disorder by 51% and depression by 45%. These figures reflect increases in these problems directly attributable to infection with COVID, and controls for increases in these problems that are part of the societal changes in the pandemic.
The new finding of long COVID as a common consequence of COVID in children and adolescents means that it is not safe for children, even previously healthy children, to be exposed to COVID at school. The findings of specific problems with fatigue, concentration, headache, and psychiatric problems show that being exposed to COVID at school is likely to interfere with student success.
What about students who are not able to wear masks for medical reasons?
Students who are neurodiverse, have sensory processing disorder, or other cognitive disabilities may not be able to wear masks. They should be medically exempted from mask wearing, or some jurisdictions may prefer a no-barrier easy parental exemption. These students are protected as far as possible by implementing the use of near-universal masking by other students and staff. These students can still attend school safely if a mask mandate is in place; whereas when no mask mandate is in place, students in general, and medically vulnerable students in particular, cannot attend school safely.
What about harms from mask wearing?
Claims of decompensation from a physiologic or pathologic perspective were quickly shown false. Low oxygen, high carbon dioxide or serious respiratory harms do not occur. A good summary is found here. This paper also shows that some people find wearing masks uncomfortable and that skin irritation and headaches sometimes occur. Note that these effects are related to the wearing of masks and do not persist for 12 weeks or more, unlike the headaches, lack of concentration, and psychiatric syndromes in children who have long COVID.
About problems with social or linguistic development, the American Academy of Pediatrics, on HealthyChildren.org, wrote on August 2021: “While this is a natural concern, there is no known evidence that use of face masks interferes with speech and language development or social communication. Plus, children can still get plenty of face time at home with mask-free family members.”
The US Centers for Disease Control (CDC) summary identifies no physical or psychological harms. A small proportion of children report irritation, headache, or difficulty breathing in physical education.
Toddlers, children and adults identify emotion less well when someone is wearing a mask, and the difference is greatest for toddlers, suggesting it is important to have face time at home without masks.
Another study of children 7 – 13 y found that the decrease in ability to read emotions was similar in size to the decrease caused by looking at someone wearing sunglasses.
Most children have already had COVID. Isn’t it too late?
Second and third infections with COVID are common. While vaccines prevent hospitalization and death, neither prior infection nor vaccination reliably prevents reinfection. Reinfection is more common with later variants.
Each reinfection carries the same risk of long COVID.
Do masks work?
Yes, all masks work, some better than others. At the beginning of the pandemic, there was serious scientific debate about this, which is now resolved. A summary of the filtration properties of different mask types, with a downloadable infographic, can be found here; and a summary of population-based studies here.
The best way to prevent any kind of pollution is to control it at the source, before the environment is contaminated. This is why we wear masks to prevent our infectious particles reaching the air that others with breath. My mask protects you, your mask protects me. Masks do also protect the wearer, though: the panel above is specifically a summary of studies of protection against tiny (less than one micron) particles reaching human volunteers. My mask protects me, your mask protects you. Masks work best when everyone wears them, which is why we asking for a mandate. Our masks protect us all. This is a great opportunity to teach our children the value of acting societally and protecting everyone.
Students can immediately return to wearing the masks they used during mask mandates. Education about which masks are better and promotion or provision of better masks would improve mask efficiency over time.
Do masks work in schools?
Yes, they do. In a 2021 study of K-5 schools in Georgia, US, different schools used different methods to reduce the spread of COVID-19. Adjusted for other factors, universal masking in schools reduced covid incidence by 37% and improved ventilation by 39%. Published in the New England Journal of Medicine, 24 November 2022, direct data show that mask mandates work in schools. In Massachusetts, when the state-wide mask mandate was removed, a number of individual school boards kept theirs, allowing for direct comparisons between boards with an ongoing mask mandate and boards with no mask mandate.
The boards that kept their mask mandates had much less COVID in the months that followed than those that gave them up. Absences among staff and students were much lower. This reinforces the point about student success. Students are more likely to succeed when they, their classmates and their teachers are in school wearing a mask than when they are home with COVID or other respiratory illness.
Do children touch their faces more when wearing masks?
No, they do not. Published in JAMA Pediatrics 24 October 2022, a randomized trial was conducted in students in a simulated school environment in Toronto, Ontario. Students were assigned to wear a mask or not to wear a mask by a random process that eliminates bias. Disease transmission would be expected only if hands contact the nose and mouth. Masks reduced this kind of risky contact by 88%, to 4 per hour in the mask-wearing group, compared with 27 per hour in the non-mask-wearing group. Touching some part of the face, including the mask in students assigned to mask wearing, occurred on average 88 times an hour. This behaviour was not increased by mask wearing: it was exactly the same in the students assigned to wear masks as those who were assigned to no masks.
Isn’t one-way masking enough?
No, one-way masking is not good enough. Even a fit-tested brand-new N95 is only 99% protective. Students do not have access to fit testing, and many do not have access to high-filtration masks.
Without masks, COVID is in many classrooms. No mask will protect students adequately against 35 hours a week of potential exposure.
School boards have to choose whether or not to make masks mandatory. When school boards don’t address the question, defer the decision, or defer to public health, school boards are actively making a choice not to mask.
The choice is between two groups of students: one group will be disadvantaged. But the harms to the disadvantaged group are not equal or equivalent:
When there is a mask mandate, students who cannot wear a mask are different, and may be disturbed and upset by the appearance of others wearing masks around them. But they are protected from COVID as best they can be, by other people’s masks. And all the other students are as safe as you can make them. There is also the potential to reduce the magnitude of this difference over time because children get used to wearing masks and seeing others in mask. Depending on cognitive abilities, some students will also be able to learn over time that masks are a sign of caring for others.
When there is no mask mandate, students who must wear a mask are different, and may be disturbed and upset by the lack of compassion of those around them - and they are not protected from a disease that could take their life. And all the other students are at risk of educational disruption from sickness, and long COVID.
It is wrong to expose all students to educational disruption and a potentially life-altering illness to normalize the school experience for students who cannot wear a mask.
What is public health’s position?
World Health Organization (WHO)
“Masks are a key measure to reduce transmission and save lives.
Wearing well-fitted masks should be used as part of a comprehensive ‘Do it all!’ approach including maintaining physical distancing, avoiding crowded, closed and close-contact settings, ensuring good ventilation of indoor spaces, cleaning hands regularly, and covering sneezes and coughs with a tissue of bent elbow.
Depending on the type, masks can be used for either protection of healthy persons or to prevent onward transmission, or both.”
https://www.who.int/news-room/questions-and-answers/item/coronavirus-disease-covid-19-masks
In the US
On 5 December 2022, Dr Rochelle Walensky, the Director of the Centers for Disease Control Prevention (CDC) encouraged people to wear masks to help reduce the spread of respiratory illnesses this season as Covid, flu and RSV circulate at the same time. Dr Walensky said “We also encourage you to wear a high-quality, well-fitting mask to prevent the spread of respiratory illnesses.”
In Canada
On 10 November 2022, Dr Theresa Tam, Canada's chief public health officer, advocated using mask as one method of reducing the spread of respiratory viruses. Dr Tam said "If it's added to the other layers of protection, including vaccination, then it might actually make a difference in terms of dampening the surge so that the hospitals can cope just a little bit better."
https://www.cbc.ca/news/health/masks-covid-flu-rsv-1.6647388
In Ontario, Canada
On 14 November 2022, Ontario’s Chief Medical Officer of Health, Dr Kieran Moore “strongly recommended” that Ontarians wear masks “in all indoor health settings, including schools and childcare.”
https://www.cbc.ca/news/canada/toronto/ontario-dr-kieran-moore-announcement-1.6650571#presentation
In Australia
“Wearing a mask can help protect you and those around you.” https://www.health.gov.au/health-alerts/covid-19/protect-yourself-and-others#:~:text=We%20may%20be%20required%20to,medical%20or%20high%20risk%20facility
In Northern Ireland
“Strongly recommended in all indoor settings accessible to the public”
https://www.nidirect.gov.uk/articles/coronavirus-covid-19-face-coverings-guidance
In Wales
“If we all keep doing the following protective behaviours, we can continue to keep each other and Wales safe:”…“wear a face covering in indoor crowded or enclosed places.”
In Scotland
“It is strongly recommended that face coverings continue to be worn where appropriate – including in indoor crowded spaces and on public transport”
https://www.gov.scot/news/use-of-face-coverings/
In the UK, schools and childcare
“PPE can protect individuals and staff from contamination with blood or bodily fluids, which may contain germs that spread disease. PPE should be used in line with risk assessments in all settings, proportionate to the risk identified.”
In New Zealand
“We encourage you to wear a face mask in crowded places, such as public transport, or when visiting people at high risk.”
What does the general public think about mask mandates in general?
Many countries badly affected by COVID do not have a mask-wearing culture. Many people who are not currently wearing masks are prepared to wear a mask if there is a mandate, or actively support mandates.
For the US, you can access the latest poll from Data for Progress here.
For Canada, late 2022:
In a November 2022 poll conducted by Nanos Research for CTV news, 71% of Ontarians support or strongly support mask mandates, if necessary.
In a December 2022 poll conducted by the Angus Reid Institute, 54% of Canadians said that their provincial chief medical officer of health should bring back mask mandates if cases continue to rise this winter, including 23% of people who currently never wear a mask.
In summary, COVID leads to long COVID in 4% of children: this is a threat to student safety. Fatigue and brain-fog as part of long COVID are a threat to student success. Mask mandates in schools reduce transmission in schools, which leads to more staff and students in classrooms, as well as a reduced risk of COVID and long COVID.
People know things are bad, they just don’t want to wear a mask if they don’t have to, and if others aren’t. They are waiting for leaders to let them know it’s time.