Another guest blog, this one by TES’ resident virologist Dr Shetal Arjan-Odedra. Shetal is a former virology researcher turned teacher, so she knows a thing or two about viruses and classrooms.
The number of secondary schools in England now impacted by COVID19 has risen from 8% in September to approximately 50% by half-term. This may be in the form of some students and teachers isolating, to partial or full closures. In comparison, primary schools have been less affected with approximately 16% of schools having to send pupils home to isolate.
Research now shows that these differences can be attributed to the age of students. Younger students tend to be asymptomatic, present mild symptoms or gastrointestinal symptoms, whereas older students could present typical adult symptoms. Consequently, young children may transmit less via respiratory droplets or aerosols if they are, for example, not coughing. On the other hand, it may just be that young children are simply tested less owing to these differences in symptoms.
Importantly, children of all ages are infected and do transmit the virus.
With disruption to secondary schools on the rise, it is apparent that a change is necessary. The most obvious and scientifically rooted solution is the compulsory use of face masks in both communal spaces and classrooms by teachers and students.
What does science say about face masks?
This data is messy, confusing and has contributed to the distrust of people towards the efficacy of face masks. This is partly due to the variety of masks being used by the public too. Although, we are confident that medical-grade face masks reduce SARS-CoV2 transmission, this has not been so clear for regular cloth face masks. At least not for the public.
However, it is unmistakeable to many scientists that mask-wearing has multiple benefits. It reduces transmission and also confers some protection to the wearer. Furthermore, masks play a role in decreasing the viral exposure/infectious dose, which may reduce the severity of the disease in the event that you are productively infected.
A recent study comparing 200 countries where mask-wearing is the standard or recommended by the government revealed per-capita mortality rates to be four times lower. Animal studies corroborate these findings too, whereby mask-wearing animals are found to be at lower risk of becoming infected, and those that are infected tend to suffer with a milder form of the disease.
How do face masks stop transmission?
Although we mostly understand the benefits of wearing a mask in impeding transmission via larger respiratory droplets, the scientific basis for mask-wearing to prevent aerosol transmission is often questioned. Aerosols are smaller droplets that travel further and remain suspended in the air for longer, especially in small, unventilated spaces. These are often likened to the spreading of cigarette smoke.
Considering most of us are not using N95 respirators, we can divert our attention to regular cloth masks. These are currently used in communal areas by many teachers and students in secondary schools in England. Interestingly, an unpublished study conducted by an environmental engineer at Virginia Tech found a cotton t-shirt was able to block inhaled and exhaled aerosols measuring only 2µm by up to 50% and 80%, respectively, and this percentage was improved for droplets measuring above 5µm (respiratory droplets).
Significantly, using cloth masks with multiple layers of different fabrics, for example, cotton and silk, in a single mask could be more effective at restricting aerosol transmission.
What is the relationship between wearing face masks and human psychology?
Human behaviour plays a critical role in the effectiveness of face masks. Beyond wearing masks consistently and correctly, evidence suggests that those that wear masks are less likely to partake in risky behaviour. Wearing a mask may remind individuals to adhere to other COVID19 measures in place too, such as social distancing and handwashing. Quite obviously, you are also less likely to touch your face with a mask on, which has implications for surface/fomite transmission as well.
Why should wearing masks be compulsory in the classroom?
Secondary school students in Ireland are required to wear masks in classrooms and students are sent home if they refuse, except in the instance of medical conditions. Is it a coincidence that hospital admission rates are much lower in Ireland compared to England and the rest of the UK?
The benefits of wearing masks in classrooms are obvious and reinforced by scientific research. Although further studies may be required and we acknowledge that face masks are not infallible, mandatory mask-wearing in secondary school classrooms, in conjunction with other layered COVID19 measures, offers a simple and cost-effective solution to addressing the ongoing interruption to schooling.
We are amidst a global pandemic caused by a virus that we do not yet understand – a virus that has the capacity to cause healthy individuals’ serious long-term complications by infecting multiple systems in the body. If only we could glimpse into the future to see the impact of this infection on teachers and students. We can, however, don a cloth face mask in settings where a 2-metre distance is difficult to maintain, i.e. classrooms, and this should be made mandatory by the Department of Education.
Editor: For me, whilst there will be difficulties in managing mask wearing in classrooms, the benefits to society (slowing the spread) and to children’s education (fewer year groups all out, fewer individual children self-isolating and more in person teaching) outweigh the difficulties and mandating their use for the majority at a national level will make classroom management easier, and I support Dr Arjan-Odedra’s call for masks to be mandatory for the majority.
Dr Wilkinson - Science Teacher 