From Thursday 5th November, the UK will once again be in lockdown.

As has been made clear by a wealth of evidence, a nationwide lockdown is now necessary if we are to regain control over the spread of COVID-19, prevent the NHS from being overwhelmed and limit the number of people who die from the virus this winter.

At PP-L, we welcome this intervention however we regret that the virus could not be contained while allowing businesses to reopen and daily life to resume. We also have strong reservations regarding the government’s insistence that schools, colleges and universities should remain open throughout the lockdown.

While we accept that there are many non-medical benefits to children and young people being in school and receiving a high quality education, we believe that, under present conditions, these benefits are outweighed by the risk of those students and school staff contracting COVID-19 and spreading the virus to others.

However, we believe that it is possible for educational settings to remain open for all year groups, with the immediate implementation of UV-C air disinfection systems in all classrooms, lecture theatres and other indoor educational settings.

Transmission of COVID-19 in education settings

The latest figures from the Office for National Statistics (up to 23rd October 2020) have shown that infection rates among secondary school pupils “appear to be steeply increasing”, with an estimated 2% of children in Year 7 to Year 11 testing positive for the virus in the most recent week of testing. This equates to approximately 154,000 infections per week, 27% of all weekly infections.

As a result, secondary school pupils have the highest positivity rating of any age group, with the exception of sixth-formers and young adults, many of whom are also attending higher or upper educational institutions.

More troubling, the proportion of infections in this age group is doubling every nine days. If this exponential rise in transmission continues, the figure may now stand at 308,000 11 to 16 year olds being infected per week. By Mid-November, this could be 616,000.

As has been well documented, universities have also driven up the number of infections across the country, with 35,000 positive cases having been recorded on UK campuses and there are likely to be many more which have been unrecorded.

There is also evidence that the reopening of schools, colleges and universities to all students from September has also had a significant impact on the transmission of the virus throughout society, contributing to the rapid increase in cases across all age groups which has made the second lockdown necessary.

Figures from Public Health England’s COVID-19 epidemiology surveillance summary showed that between 21st August and 27th September, educational settings accounted for 45% of all positive cases in the UK.

Although evidence has shown that younger children are less likely to experience severe symptoms than adults, secondary school pupils are thought to be able to spread the virus just as easily. This means that school, college and university staff, particularly teachers also face a high risk of exposure to the virus, although little information has been published on the occupations of people who have tested positive for the virus in the UK.

Now, the largest teaching union in the country, the National Education Union (NEU) as well as the University and College Union (UCU), along with the mayors of Greater Manchester and Liverpool are calling for these settings to be closed as part of the lockdown measures, with an increased use of online learning. Their case is also supported by many leading scientists, including members of the government’s Scientific Advisory Group for Emergencies (SAGE) and the Independent SAGE.

Students in school classroom raising their hands

School closures can be avoided

However, instead of closing schools, we believe that it is possible for the risk to be managed through the implementation of safe, cost-effective measures which go above and beyond the steps which have been taken by schools across the country.

Fundamentally, these measures must mitigate the risk of the airborne transmission of COVID-19 through the widespread use of UV-C air disinfection systems or upper-room germicidal UV.

Based on the latest scientific evidence and data, it is our view that schools can only remain open safely if these systems are installed within every classroom across the country, in addition to the continued adherence to the existing guidance issued by the Department of Education.

Not only can this technology be used to ensure schools remain open throughout the second lockdown, but it can also reduce the risk of transmission within these settings when the lockdown measures are relaxed, reducing the risk of future spikes in transmission.

The airborne transmission of COVID-19

Since the government first set out its guidance to enable schools to reopen for some students before the summer, far more has been learned about COVID-19 and its transmission than was known at the time. In particular, health authorities around the world now recognise three main means by which the virus is spread.

This includes transmission through droplets which are produced by people speaking or coughing which can end up in the mouth, eyes or nose of people standing nearby; physical contact with surfaces which have been contaminated (although the US Centers for Disease Control and Prevention and European Center for Disease Control and Prevention have now stated that this is now thought to be the least likely means of transmission); and transmission by aerosols or airborne microdroplets which can be exhaled into the air through breathing or speaking where they can linger or be carried by air currents.

Since the pandemic began, this airborne means of transmission has been shown to be of crucial importance; with several studies demonstrating that aerosols which carry COVID-19 can remain airborne for up to 16 hours and can travel up to eight metres, with cool, indoor environments being particular risk areas.

Having been derived from measures designed to manage a pandemic with flu-like symptoms, the current guidance being followed by educational settings and workplaces include a variety of measures to prevent the transmission of the virus through droplets and through contaminated surfaces, but they do little to prevent the airborne transmission of microdroplets. These microdroplets can easily spread beyond the recommended two metre distances between classmates or teachers and they can become increasingly concentrated if not diffused through ventilation, increasing the risk of infection.

How to eliminate airborne pathogens from classrooms

As has been explained, the risk posed by airborne particles can be effectively mitigated by ensuring that there is good ventilation. However, this must be from an outside source such as a window, rather than from a standard air circulation device, air purifiers or air conditioning unit. This is because of the small size of microdroplets (smaller than 100 micrometres in diameter) which means microdroplets can easily pass through the filters of these devices. Indeed, this means that their use can instead circulate and spread the infected microdroplets further, rather than removing them.

Compared to these systems, air from the outside is a far safer source of ventilation as this air has been exposed to ultraviolet light, which quickly destroys almost all pathogens including COVID-19 and viral particles will have been widely dispersed, reducing their concentration (although there is evidence that this may not be as effective in densely populated areas).

However, where it is not possible to guarantee good ventilation or when outside weather means it would be too cold to have windows open, it is vital that airborne microdroplets are safely destroyed through the use of air disinfection systems which use germicidal ultraviolet light (UV-C / UVGI).

UV-C has proved to be very effective in rapidly inactivating and destroying airborne coronaviruses, including COVID-19 as well as other airborne pathogens such as measles and tuberculosis which are even more contagious. UV-C light has been shown to inactivate 99.9% of COVID-19 viral particles in milliseconds.

This technology has been used for over a century as a means of destroying harmful pathogens, and its tremendous effectiveness has been proven by more than 4000 research papers to destroy pathogens and much more complex bacteria and viruses than this latest coronavirus.

While direct exposure to UV-C can be harmful, the technology can be utilised safely within an air circulation or ventilation system such as an airconditioning unit, air purifier, or heating and cooling system where it is only applied to the air which passes through the unit. This enables UV-C to disinfect all of the air within a room continuously, even while the room is occupied.

If utilised within a typical classroom, an inexpensive UV-C air disinfection unit can continuously disinfect all of the air within a classroom every 15 minutes, preventing the concentration of viral airborne particles, and dramatically reducing the risk of infection.

Failure to act is not an option

With schools, further education and higher education institutions continuing to run as before, the country risks a damaging month long lockdown which will fail to meaningfully reduce the rise of infections.

As secondary school age children, and college and university aged young people are the two age groups most likely to be infected with COVID-19, we believe it is likely that the pandemic will continue to spread unmitigated within educational settings. As a result, school staff and students will be forced into unsafe conditions where they will face an ever increasing likelihood of catching the virus and spreading it to others.

As well as the high risk of infection, failure to install these systems will also require schools to choose between unacceptable workplace temperatures or unsafe air quality:

Throughout November, the average outside temperature in the UK will range from 5-11°C. If windows are to be relied upon as the only means of eliminating airborne pathogens, this means indoor temperatures are likely to fall below the government’s recommended minimum workplace temperature of 16°C for non-physical work. These low temperatures will also aid the transmission of the virus, limiting the benefit of the ventilation by helping the virus to remain viable. If windows are closed however, viral concentration will increase meaning schools are unable to ensure clean and fresh air as required by health and safety at work law, due to the risk of viral infection.

Neither of these options are acceptable for staff and students who will be forced into these environments.

For these multiple reasons, we believe that for schools, colleges and universities to remain open for on-site learning during this second lockdown and beyond, UV-C air disinfection systems must be installed as standard at every classroom, lecture theatre or other indoor learning facility as a matter of urgency.

If you would like any additional information about UV-C air disinfection technology or to speak to a member of our team, please contact us.

Dr Rhys Thomas MM’BBs MD FRCA Dip IMC RC’Ed

Chief Medical & Scientific Officer

PP-L Health Technology Solutions

Paul Waldeck B.Eng.(Hons.) ,C.Eng,. MI.C.E., M.I.Struct.E..

Chief Technical Officer

PP-L Health Technology Solutions