So How do We Solve This?
Five Solutions to Bring Clean Air for Bristol’s Kids and Beyond
High levels of Carbon Dioxide (CO₂) mean the air is potentially a risk; you are breathing in a lot of air that has been breathed out by someone else
Monitor CO₂ levels
Opening doors and windows brings outdoor air in; it removes stale air and pollutants, pathogens, and harmful particles that you otherwise would breathe in
Ventilation
Filtration
Air filters remove airborne particles from the air such as dust, pollen, viruses, bacteria, smoke and other pollutants such as fungal or mould spores
That way you won’t infect other people. Thank you for being considerate
Stay home when sick
About the harms of breathing poor quality air and the benefits of breathing clean air
Learn
All About Carbon Dioxide (CO₂)
Airborne diseases spread much better inside than outside; where people share the air in enclosed spaces. When an infected person breathes out, they exhale microscopic particles laden with virus which can stay invisibly suspended in the air for hours along with the CO₂ we all exhale naturally. Good ventilation helps to remove these particles and reduce the risk of infections spreading.
We can’t easily measure what viruses are being exhaled, but we can measure CO₂ levels, which shows how much of the air we are breathing in has been breathed out by others.
The UK government spent £49million on supplying all schools with CO₂ monitors but this initiative has been poorly run, with limited training available for educators and no facility for externally collecting the data from classrooms. The outcome is that air quality in schools is not routinely assessed; in reality CO₂ monitors are just not present in classrooms any longer.
Carbon Dioxide (CO₂) monitors tell us about how much of the air we are breathing in, has been breathed out by others.
When we exhale, we release air with a higher concentration of CO₂ that we inhale. Outdoors, this excess CO₂ quickly disperses into the atmosphere. However in indoor spaces, where air is more confined, CO₂ levels gradually rise the longer the room is occupied. The effect is amplified in crowded spaces, as each person adds more CO₂ to the air.
Why we measure CO₂
What the CO₂ should be in an indoor space
The CO₂ concentration is measured in parts per million (ppm). The CO₂ level outdoors is approximately 420ppm. The aim is to get the indoor air as close as possible to the outdoor air.
The recommended threshold for the lowest risk indoors is to have CO₂ under 800ppm. Unfortunately with densely packed classrooms and inadequate ventilation, this level is almost impossible to achieve.
Compact, portable monitors are available which reliably measure CO₂ in the air.
Some of them can log the data, so it’s possible to review what happens to the CO₂ levels across the day. Rather than just on-the-spot monitoring. Logging the data is essential for demonstrating that the CO₂ in a classroom is not safe.
The best type for measuring CO₂ are those with a NDIR (Non-Dispersive Infrared) sensor. This works by detecting how much infrared (IR) light is absorbed by CO₂ molecules and they display the result in ppm (parts per million).
How we measure CO₂
Improve Ventilation
Proper ventilation is essential for comfort, health and safety. It helps remove pollutants, moisture and odours whilst ensuring an adequate oxygen supply.
Ventilation is the process of supplying outdoor air to a room and removing stale air from that enclosed space, to maintain good air quality. The problem is, is that it is variable and dependent on outdoor conditions.
It can occur naturally – through windows, vents or gaps
Or mechanically – using fans or mechanically ventilated systems
90% of UK schools are naturally ventilated but with densely packed classrooms, opening windows is not enough on its own. Air filtration must be added to classrooms and school halls to achieve good air quality.
Health: Breathing in fresh air, as opposed to stale or polluted indoor air, reduces the risk of airborne diseases and respiratory issues. Pollutants may accumulate in poorly ventilated spaces, leading to acute and chronic health problems.
Humidity: A well-ventilated space can prevent the build-up of odours and excess humidity, ensuring a comfortable indoor environment.
Buildings: Good ventilation can prevent damage to the building from excess moisture; this can cause mould growth and structural damage.
Energy Efficiency: Bringing in outdoor air can sometimes help maintain an appropriate temperature and humidity levels in buildings; reducing the strain on heating systems and potentially lowering costs.
Add Air Filtration
Filtration is the process of removing airborne particles from the air. It traps particles such as dust, pollen, viruses, bacteria, smoke and other pollutants such as fungal or mould spores.
Air filtration is commonly used in mechanically ventilated systems but also as a stand-alone portable plug-in filter to improve air quality and protect respiratory health.
Air filters can significantly increase the clean air supply in a classroom and therefore can be considered a cost-effective measure.
How are Air Filters Used?
Crucially, the school staff need to be engaged in managing the filters. They must be running continuously throughout the day; switched on at 8.30am and off at 5pm around one hour after the room has been vacated. There is no need for them to be left on overnight in an empty room.
How Should I Choose an Air Filter?
It is critical to install a filter with the appropriate Clean Air Delivery Rate (CADR) otherwise the air will not be as safe as it should be. It is important to get the right filter for the size of the space and potentially more than one machine. The World Health Organisation recommends SIX Air Changes Per Hour (ACH) of ventilation for schools.
Air Changes Per Hour means the number of times that the total air volume in a room or space is completely removed and replaced in an hour. But with air filtration, the air is not removed, it instead cleans the air of particles that are already in the room. This is therefore called equivalent Air Changes Per Hour (eACH).
How Much Does a Filter Cost?
A rough calculation of the cost for a two-class entry primary school is approximately £5000.00, which equates to around £10 per child per year.
After that initial layout, in subsequent years the cost would be less because the school would only need funding for replacement filter panels.
How do Air Filters Work?
It is a simple but effective concept that was designed in World War II to filter radioactive particles. The filter panels are comprised of multi-layered mesh made of very fine polypropylene or fibre-glass threads. Using an in-built fan, the air circulating in the room is pulled in through the high-grade filter. This will trap 99.97% of the airborne contaminants that are present. The filtered, cleaner air blows out of the top of the fan back into the indoor space.
Stay home when sick
The simplest way to reduce sickness is for an infected person to stay home and not to infect another person. However, in our society the current prevailing culture is one of ‘pushing on through a cold’ and of presenteeism.
A report by the Institute for Public Policy Research looks at how presenteeism (working when sick) is having a significant economic impact on productivity of the workforce. They say that: “The estimated cost of working through sickness far outweighs that of taking sick leave”.
It also states: “The most recent data found that employees lost 43.6 productive days on average due to presenteeism but 6.7 days due to absenteeism.” This is because when people go to work when sick, they infect many other people, both within their own workplace and when travelling there and back.
Staying home when sick would require a major public education campaign, although the benefits would be huge. It would also require better societal support: universal sick pay, the ability to work from home when sick (and to school from home when sick) and to have locum employees for where the work requires somebody to be in attendance to undertake it.
We all know about people from Japan and South Korea routinely wearing masks when sick with a disease that is transmissible through aerosol or droplets, and these are worn to protect others. This behaviour is learnt during the original SARS1 epidemic in 2003 that endures. It should become part of the cultural change in the UK as part of reducing sickness absences. After all, if you are sick with something, why on earth would you want to infect someone else? We need to become kinder to others.
Learn
Humans need three basic things to survive: water to drink; food to eat; and air to breathe. There are standards for two of those that are readily accepted and expected, but there are no regulations for indoor air.
Since the 19th century cholera outbreaks, the need for clean water has been recognised and the water that we consume is now sanitised and regulated. We expect to drink clean water.
It is now taken for granted that the food we buy and are served in restaurants is safe and hygienic. The link between contaminated food and diseases such as salmonella, listeria and E. coli is now accepted.
We currently have no expectations about the quality of the air we breathe and are prepared to breathe in anything. We just put up with the (avoidable) illnesses, health complications and other negative impacts on our quality of life and our performance in life and work that result. It’s driven by the fact that we rarely can see the pollution in air, whether that be the viruses and bacteria, or particulate matter or pollutants from traffic and transport.
According to the UK Government, poor air quality is the largest environmental risk to public health in the UK, as long-term exposure to air pollution can cause chronic conditions such as cardiovascular and respiratory diseases as well as lung cancer, leading to reduced life expectancy. In 2010, the Environment Audit Committee considered that the cost of health impacts of air pollution was likely to exceed estimates of £8-20bn.
Epidemiological studies have shown that long-term exposure to air pollution reduces life expectancy. Short-term exposure (over hours or days) to elevated levels of air pollution can also cause a range of health impacts, including effects on lung function, exacerbation of asthma, increases in respiratory and cardiovascular hospital admissions and mortality.
According to research from Asthma UK and the British Lung Foundation 99% of schools in the UK are in areas that exceed the WHO’s recommended limit for harmful PM2.5 particles. Every day, an estimated 3.1 million children in England attend schools where the air surrounding them is over WHO’s recommended limits for Particulate Matter (PM2.5). Just 13 schools in the whole of the UK (all in rural Scotland) are in areas which don’t exceed the WHO’s recommended limit for PM2.5.
What we Can Do to Improve Air Quality in Schools
The Problem with School buildings
It is not always feasible to open classroom windows if they are broken, sealed shut or it’s cold and windy outside. If a school is in an area of high air pollution, fresh air from outside is not possible. Getting CO₂ under 800ppm can be very difficult, especially as most UK state schools are reliant exclusively on windows. There is also the problem of heating energy being lost out of open windows during the winter season.
Many school buildings are generally in poor condition and require extensive refurbishment. This should include upgrades to mechanical ventilation with heat recovery (MVHR) systems. The schools in the UK are often old buildings and all unique; therefore every educational setting needs to be properly assessed by a ventilation engineer. This all requires substantial financial investment from the government and time to repair the buildings.
What We Can Do Right Now
An immediate way to improve school air quality is to install portable air filters. They have low energy consumption, drawing a similar amount of power as a lightbulb. This means in winter it can provide a more energy-efficient strategy than opening windows wider, thereby saving money on heating bills. Filters will not reduce the CO₂ levels but will make the room safer to occupy. Extraction fans and ceiling fans can also assist ventilation.
An air filter is an effective way to supplement ventilation. It will significantly reduce disease transmission risks, asthma triggers, other pollutants and consequently school absence.
Other strategies that have been considered in schools (such as ionization, plasma systems or UV) are considered less cost-effective or scientifically defensible due to their unproven efficacies and their potential for degrading the quality of the air through the generation of harmful secondary pollutants.
Our Vision is to provide cleaner indoor air to benefit the health of all children
Ventilation
Opening windows lets stale indoor air out and the external air flow in
Filtration
Removing particulate matter from the room air using air filters
Legislation
Campaigning for better standards for indoor air quality
Do you want clean air for kids in Bristol’s schools?
If you support our campaign for clean air for kids in Bristol’s schools, please send us a message.
If you want to learn more about the benefits and the solutions, please get in touch.
If you want to help us, fill in the form and tell us.
And if you want to advocate for clean air in your own child’s school, we’d love to hear from you. We can help!