A technological, science-led approach, will protect against airborne COVID, and there’s a solution right here in Ireland
By now, most of us would have hoped that the vaccine roll-out would have signalled a return to normality. However, with new variants emerging, a slower than expected vaccination programme in developing countries, as well as cohorts of populations electing to go unvaccinated, it’s becoming clear that we may be living with COVID-19 for a while yet.
The advice from national Governments has been consistent throughout the pandemic, beginning with hands, surfaces, masks and social distancing. Following global research warning that airborne transmission poses a far greater risk than surface contamination, most health authorities including the HSE have added ventilation to their guidelines.
More recently, Carbon Dioxide (CO2) monitors have been recommended as another way of mitigating risks, and the Department of Education here has included these devices as part of their guidance. The Department is said to be procuring a number per school for use from September.
Effectiveness of ventilation / CO2 monitors
Although ventilation can reduce the risks to a certain extent, it is not a silver bullet and does not solve the problem. Let’s take an average sized classroom with 26 students. The teacher opens the window(s), what happens next?
Considering that 100 million particles of Coronavirus can fit on the head of a pin, it’s clear that any virus in the room will not simply disappear out of the window. Dilution of indoor air through ventilation is slow and time consuming; it’s also a grey area in terms of when rooms or spaces need to be ventilated – and for how long.
In addition, ventilation on its own will not inactivate any micro-organisms in the air. At best, opening a window will replace the indoor air with fresh outdoor air; at worst it will do absolutely nothing or (worse still!) bring in even more polluted air.
If you consider that air movement is chaotic and uneven we will never know how the air is moving in a room, where it is moving to and if ventilation is pushing infected viral particles towards occupants in one part of the room. Very often, opening a window just moves the same pockets of dead or infected air around a room.
For schools or workplaces, having windows open in the depths of an Irish winter is also cold and uncomfortable. For students and teachers in particular, a cold classroom is not conducive to learning or concentration.
- CO2 Monitors
As with ventilation, CO2 monitors can help reduce risks but they are not a silver bullet. The Department of Education guidance states that CO2 monitors can play a part in providing a “useful general indication that areas/rooms may not be adequately ventilated”. So again, if we take an average sized classroom with a CO2 monitor installed, what happens next?
The CO2 monitor alarm goes off or the lights indicate that CO2 levels are increasing. The teacher opens a window or moves the class outside to allow the levels time to reduce. But of course, in winter, it is cold and potentially raining or snowing outside. The teacher closes the windows or returns to the classroom, settles the students back in. But for how long?
Air quality is affected by the number of people in an indoor space; their age and metabolic rate; and what they’re doing. This means in a secondary school it could take longer for CO2 levels to reduce compared to a primary school classroom. If students are removed from the classroom, they will be breathing out higher levels of CO2 due to the increased activity of the walk in and out, which means when the window is closed again, the chances are the CO2 levels will simply shoot back up.
Not only is all this opening and closing potentially very disruptive, even if CO2 monitors indicate that a window needs to be opened, ventilation falls way short of properly dealing with a virus whose particles can amass in the hundreds of millions on a single pinhead.
Professor Cath Noakes, Professor of Environmental Engineering for Buildings at the University of Leeds, provides this advice on CO2 monitors on her Twitter account, “It’s important to remember CO2 is only a guide. The numbers are not exact and they don’t tell you the actual risk from the virus. CO2 increases when there are more people in a space and decreases when ventilation is increased. So the value tells you about ventilation AND occupancy”.
To put this in perspective CO2 monitors tell you what you already know, you have too many people in a room and the ventilation is poor. Once you open a window or vacate a room while CO2 levels will most likely decrease the monitors provide no indication of whether airborne viruses and pathogens are in the air or if they are increasing or decreasing.
You also have to consider that hearing or keeping an eye on the monitor throughout the day is far from guaranteed in a busy classroom, restaurant or hairdressing salon.
A science-led, multi measured approach and solution
The problem is that no single measure to prevent the spread of the virus is 100% effective and that includes vaccines, we have to use multiple safety measures. This is illustrated in the Swiss Cheese Model by the BBC Visual Journalism Team who show that by using a number of slices – or measures – that we create the best chance of protecting ourselves and our friends and family.
BBC Swiss Cheese Model: https://www.bbc.co.uk/news/resources/idt-40ac92b1-1750-4e86-9936-2cda6b0acb3f?s=03
CO2 monitors and ventilation can help to mitigate risks to a certain extent but with significant evidence demonstrating that the primary route of virus transmission is now airborne, part of these measures need to include inactivating Covid-19 in the air, not just massaging it or pushing it around. Irish-made Novaerus NanoStrike technology can do just that. The devices are scientifically proven to inactivate SARS-CoV-2 (the virus that causes Covid-19) by 99.997%, and are completely safe to use 24/7 around children, the elderly and those who are vulnerable.
The bottom line is that Novaerus working alongside recommended guidelines is the key to a safe return for schools and workplaces and can help facilitate a return to normality – a proudly Irish-made, scientifically proven solution that can protect students, teachers, employees, customers and families. Ventilation and CO2 monitors alone are simply not enough