Continuing to tackle climate change, reducing dependence on fossil fuels, improving working conditions for millions of people – an impressive list of achievements we’ve all been jointly responsible for over the past few decades.  So what’s the next target? Something that concerns each and every one of us – clean air.

Tackling air pollution will be one of our generation’s biggest challenges. Increased urbanisation, road, sea and air congestion, along with the ever-increasing demand for power, means that air handling in London has never been more necessary.

Nowhere is clean air more important than in education. Children are particularly prone to the effects of poor air quality and education is crucial for the young to improve their chances in life. It is imperative they are given every opportunity to succeed and are not held back by issues out of their control, of which, unclean air is a major one. Because of the fact that we spend, on average, around 90% of our time indoors (a number which has been on the increase for the past half century), it is more important now than ever before that the quality of the air we breathe in is of a sufficiently high enough level.


What is ‘clean air’?

‘Clean air’ is air that has no harmful levels of pollutants in it and is safe to breathe. Air with dirt and chemicals in it is harmful to breathe in and can cause a wide array of health defects and problems (which we’ll cover later).


Indoor Air Pollution: The Causes and Dangers

Indoor air pollution is a major global health hazard. The burning of fossil fuels for heating and cooking produces emissions of dirt particles, nitrogen oxides, carbon monoxide, sulphur dioxide and many more hazardous air pollutants that are harmful to health.

Perhaps, however, the most obvious – yet often overlooked – form of indoor air pollution comes from ourselves, as human beings, and the CO2 we produce whilst breathing. Although not an issue in small numbers, when larger quantities of people are gathered together in enclosed environments – offices, schools, etc. – the effects of poor ventilation can really become serious.

Other common indoor pollutants come from tobacco smoke, radon gas – responsible for over 1,100 deaths a year in the UK – moulds and allergens arising from damp or poorly ventilated buildings and plumbing leaks, dust mites and volatile organic compounds (VOCs).

These are emitted as gases from thousands of products as diverse as paints and lacquers, printers and photocopiers, craft materials, cooking oils, building materials and chlorinated drinking water – all things found in schools.

The World Health Organisation also says 3.8 million premature deaths annually from diseases such as strokes, ischaemic heart disease, chronic obstructive pulmonary disease and lung cancer are attributed to exposure to household air pollution[1]. There is also evidence of links between indoor air pollution and low birth weight, tuberculosis, cataract, nasopharyngeal and laryngeal cancers.

It’s worth emphasising that while developing countries are affected the worst by indoor air pollution, the UK and other developed nations are by no means immune to it.

Poor ventilation, the proximity of so many buildings next to busy roads and as yet unknown dangers from plastics and cleaning products are all examples of indoor air pollution sources which need to be treated.


Why is it Particularly Important to Breathe Clean Air in Schools?

Studies have proven that allowing fresh air into the classroom could reduce student absences due to illness by 3.4%. While that may seem a low figure, applied worldwide it translates into millions of school days. One such study, undertaken in California, found that having higher quality air could also see families avoiding $80 million in childcare costs due to having a sick child at home.[2]

clean air

A 2015 study in the Journal of Environmental Economics and Management[3] demonstrated that improving schools indoor air quality positively impacts student performance. Interestingly, a one-off renovation project for ventilation or mould purposes had the same effect on test scores comparable to reducing class sizes from 24 to 15 students. At a time when UK schools have record class sizes[4], clean air is a real benefit.

Research from the University of Reading showed a direct association between the environmental conditions in classrooms and pupils’ cognitive performance. The research found that air quality conditions in 35% of classroom hours were inadequate for purpose, with pupils and teachers exposed to CO2 concentrations of up to 3.5 times the recommended average levels of 1500 ppm.  At the 8 schools tested, memory and reaction times of the children were investigated, and it was found that both were worse off when exposed to the higher levels of CO2 in the classrooms.

Clean air in classrooms is a simple way to reduce the spread of sickness. Schools have a high occupancy density, with children sitting close to each other. By the time parents realise their children are sick and take them out of school, it’s generally too late – viruses have spread.

Growing children are also more vulnerable to air pollution than adults, with exposure at a young age to pollutants inflaming pre-existing conditions and causing long-term damage, effects that are still being studied.


School Ventilation Solutions

There are numerous ways in which all types of property, whether household, commercial, places of learning and social centres can dramatically reduce air pollution.

  • Keep it clean

Keeping areas clean might sound like common-sense but its effectiveness is often understated. Vacuum cleaners that use specialised filters can be particularly effective, getting rid of concentrations of lead, toxins like brominated fire-retardant chemicals, allergens such as pollen, pet dander and dust mites.

  • Strike the right balance between humidity and ventilation

Moisture is a breeding ground for bacteria, mould and a gift for dust mites and mosquitoes. Humidity at around 30%-50% will keep them under control. A dehumidifier (and air conditioner during warmer months) reduces moisture and helps controls allergens. While air conditioners aren’t perfect they are a plus for those who suffer from allergies.

Many cooking appliances have fans. Use them but also, open a window when cooking. Overwatering indoor plants adds more moisture to the air, as does drying laundry inside. Wherever possible, this should be done outside. And ensure faulty plumbing or leaky taps are fixed promptly.

  • Test for harmful gases

In England as of 1st, October 2015, regulations require smoke alarms to be installed in rented residential accommodation and carbon monoxide alarms in rooms with a solid fuel appliance. Carbon monoxide deaths are a silent killer with hundreds of people every year in the UK needing hospital treatment and around 50 dying as a result of exposure.

In the same way a smoke alarm is considered crucial in any building, so should a carbon monoxide detector. Where a boiler/plant room forms part of a UK school this is usually required.

Radon gas comes from the natural decay of uranium found in nearly all soils. It’s the second leading cause of lung cancer in the US and doesn’t discriminate – any building, no matter how well-maintained and ventilated, is vulnerable to radon. Thankfully, testing for radon is easy[5].

  • Plants

NAASA and the Associated Landscape Contractors of America studied houseplants as a way to purify the air in space facilities. Their research demonstrated several plants that filter out common volatile organic compounds (VOCs) with many houseplants able to remove up to 87% of air toxins in 24 hours.

clean air.png 1

Nature’s lungs are known to recycle water and air. Enzymes in plant leaves work together with the roots to break down toxic chemicals into non-toxic components that can be used by the plant while foliage plants are incredibly effective at removing dust from work and home environments.

The aloe, Spider plant, Gerber daisy and snake plan are accepted as being excellent filters for indoor pollution.

  • The right ventilation system

There are a number of different approaches to ventilation, however, they can be split into either natural or mechanical systems.


Ventilation. What’s best – natural or mechanical?

The UK National Energy Efficiency Action Plan estimate that 40% of commercial floor space will be air-conditioned by 2020, a 30% increase from 1994[6]. This is a large increase in facilities that use air-conditioning, but what we must remember is that air conditioning only deals with the temperature of the air inside a building, not the quality of it.

So what’s the solution – natural or mechanical?

Both natural and mechanical ventilation have their advantages. Some natural ventilation systems benefit from low running costs and energy consumption, no noise from fans and no space taken up by mechanical equipment.

However, schools are unlikely to have enough windows open when it’s not warm outside. Many windows will also be closed full-time for safety reasons and also security concerns. A school on a busy road is unlikely to get much benefit from opening windows where outdoor air pollution is high and in many cases would be worsening indoor air quality.

Natural ventilation is variable and depends on outside conditions relative to the indoor environment. Wind and temperature difference are unpredictable. Natural ventilation can be tough to control, with airflow being uncomfortably high in some locations and stagnant in others. The limitations on automatic controls as well as the lack of filtration of the air supply are big negatives, too. In a generally cold climate, like that of the UK, is not particularly conductive to natural ventilation, even more so in a large building like a school.

Mechanical ventilation systems and air handling units can guarantee the circulation of fresh air using ducts and fans, rather than relying on airflow through small holes or cracks in a building’s walls, roof, or windows. They can also ensure the overall airflow direction in a building, meaning no uncomfortable draughts.

clean air.png 2

Mechanical ventilation can provide filtration, dehumidification, and conditioning of outside air, creating a customised indoor air environment[7]. Different mechanical systems can be used in different climates too, ensuring outside factors, like weather and sudden outbreaks of smog can be controlled. Mechanical ventilation also reduces outdoor noise pollution.

But schools, like homes and businesses, operate on a budget. Having systems running for a school day can be expensive, leading them to be switched off. Failure to adequately maintain and service systems over time will reduce the quality of the air circulating.

Mechanical ventilation systems are often cited as being difficult to operate. Lack of understanding of how it works and when it works best can result in improper use. Poor installation can also be an issue.

However, if installed properly with careful design, stringent maintenance of equipment, effective training, and guidelines that take into consideration all aspects of indoor environmental quality and energy efficiency, mechanical systems are more reliable.


Importance of Ventilation in Schools and Classrooms

So natural ventilation is free (or low cost) to operate and mechanical systems use electricity to run thereby running up a cost.  So natural ventilation is overall cheaper to use, right?


Ventilation and heating requirements for a classroom need to be considered together.  What is often not reported when looking at natural ventilation systems is the temperature of the outdoor air coming into the classroom.  A typical winter’s day can be 4°C, opening a window to provide ventilation creates a huge demand on the heating system to increase the “fresh” air to a comfortable temperature.

Mechanical systems can incorporate heat recovery technology, capturing energy from the extracted air meaning the same 4°C air will be supplied into the classroom at approx. 18°C – removing the need to heat this fresh, filtered air and significantly reducing the heating load for the school.


School Ventilation Requirements

UK school buildings are required to have the following practices in place (a full Building Bulletin can be viewed online[8]):

  • All occupied areas in a school building must have controllable ventilation.
  • Measures must be taken to prevent condensation and to remove noxious fumes from every kitchen room, with ventilation minimising draughts and providing protection against rain penetration.
  • The control of ventilation intakes to avoid pollutants from road traffic at busy period is advised. A minimum floor-to-ceiling height of at least three metres is desirable in a naturally ventilated classroom or other teaching space. Science labs, prep rooms and workshops, where activities may result in higher pollutant emission ideally should be larger.
  • Exhausts for air should be located to minimise re-entry to the building, for natural and mechanical intakes, and it is standard practice to fit filters to mechanical ventilation systems. Mechanical ventilation system air-intake filters should be used for particle removal with activated carbon filters to remove gaseous pollutants.
  • Buildings are encouraged to be airtight to prevent the uncontrolled ingress of contaminated outdoor air.

To sum up, clean air is very important for planet earth and humans alike, yet it is only really in the last quarter century that we have actively begun to seek ways of improving the quality of the air we breathe. The health effects of air pollution are well documented – at least 3 million people die per year from breathing in harmful toxins, so poor quality air in any form will have adverse effects on well-being and life. Even in small doses, such as those seen in poorly ventilated offices and classrooms, unclean air will affect your daily performance as well as do your body harm. Damage can be irreversibly done to both respiratory system and future career should young children not be able to study in an environment that is fit for needs. That is why clean air is so important, especially to those in education.






[6] (p.107)