Understanding and managing the impact of indoor air quality (IAQ) in schools

1. Why is IAQ important in schools?

In recent years, comparative risk studies performed by EPA’s Science Advisory Board have ranked indoor air pollution among the top five environmental risks to public health. Good indoor air quality is an important component of a healthy indoor environment that can help schools reach their primary goal of educating children.

Children spend approximately a quarter of their waking hours at school, where they are exposed to indoor air quality, thermal, acoustic, and lighting conditions that are beyond their control.

They are particularly at risk from air pollution because their immune systems, lungs, and brains are still developing. Children are more vulnerable, as they inhale more air than adults in proportion to their body weight. Air pollution can affect children’s physical health, their ability to learn, and, in extreme cases, could create lifelong health implications.

Research is also beginning to point towards the effects of indoor air pollution on students’ learning, behaviour, attendance, and overall educational outcomes. Yet millions of children are still exposed to dangerously high levels of air pollution. A study conducted by Global Action Plan states that almost all UK schools are in areas above WHO air pollution limits, putting around 12 million children at risk.

The impact of IAQ in schools from a health perspective.

A recent review outlined current evidence for health effects in children associated with exposure to specific indoor air pollutants in school environments. Most of the relevant published evidence relates to respiratory effects, including wheeze, atopic asthma, pneumonia, and other respiratory infections associated with children’s exposure to indoor air pollution.

According to the U.S. Environmental Protection Agency, nearly 1 in 13 school-age children has asthma, which is the leading cause of school absenteeism due to chronic illness. There is substantial evidence that indoor environmental exposure to allergens (such as dust mites, pests, and moulds) plays a role in triggering asthma symptoms. These allergens can be common in schools.

Symptoms may not necessarily be due to air quality deficiencies, but can also be caused by other factors, such as poor lighting, stress, noise and more. Non-respiratory effects include skin and eye irritations including, eczema, atopic dermatitis or conjunctivitis.
Individuals who may be particularly susceptible to the effects of indoor air contaminants include, but are not limited to, people with asthma, allergies, or chemical sensitivities; respiratory diseases; suppressed immune systems; and contact lenses.

The impact of IAQ in schools from an educational performance perspective.

Substantial evidence suggests that IAQ in classrooms influences student learning capabilities and educational attainment, though the mechanisms are not yet fully understood. An early study demonstrates that the performance and attendance of school children are intrinsically linked to IAQ, particularly through health effects caused by indoor air pollutants.

The U.S Environmental Protection Agency shows that students in classrooms with higher outdoor air ventilation rates achieve higher standardised test scores in math and reading compared with those in poorly ventilated classrooms. Improved IAQ can enhance student performance, teacher productivity, and retention.

In addition, there is evidence of direct associations between learning outcomes, including academic performance in coursework and exam assignments, as well as physiological and cognitive function tests, and classroom environmental conditions.

Chronic exposure to raised Nitrogen dioxide (NO2) and Black Carbon (BC) concentrations has been associated with detrimental effects on the development of working memory, while higher PM2.5 exposure was associated with a 22% reduction in annual improvement in children’s working memory and an 11% annual change in inattention.

2. Sources of pollution

Thousands of schools and further education centres in the UK are in air pollution hotspots. A considerable amount of air pollutants in schools comes from sources outside the school: road traffic, emissions, diesel buses, urban particulate pollution and/or construction dust. Nevertheless, pollution is also generated by activities inside the school premises, such as heating systems, cleaning products, crafting products, cooking emissions and occupants (CO2).

Air pollutants in classrooms include particulate matter (PM) of all sizes, inorganic pollutants (nitrogen dioxide, ozone, and sulphur dioxide), organic pollutants (formaldehyde, benzene, and other volatile organic compounds, and biological contaminants (mould, fungi, etc.). Some of these are generated indoors, while traffic-related air pollutants such as NO2 (from combustion engine ignition), PM2.5 (from brake wear and other sources) or pollution from industrial activities in the vicinity of the building can infiltrate indoors and significantly contribute to IAQ.

A study published by the European Public Health Conference in 2024 determined that the main pollutants affecting IAQ in schools were carbon dioxide, volatile organic compounds (e.g. formaldehyde, terpenes), particulate matter, nitrogen dioxide, radon, ozone, and carbon monoxide. Other determinants were occupants, their activities, and the building characteristics.

The presence of people can significantly alter the air quality. As stated by the Royal College of Paediatrics and Child Health, this is because our skin oil contains compounds that can react with ozone to produce a range of VOCs. Emissions from humans are called “bioeffluents” and include the smells we associate with people. However, not all pollutants that cause poor indoor air quality are detectable by smell (including those such as CO and radon).

3. Regulatory Framework in the UK

Building Bulletin 101 (BB101)-2018

• Focuses on the health effects of indoor air pollutants based on the World Health Organisation guidelines for Indoor Air Quality and the latest advice from Public Health England. It also describes pollutant sources, both internal and external pollutants, serves as guidance on how to meet the maximum exposure levels for pollutants and advises on reducing sources of indoor pollutants.

Guidance on ventilation and air quality in education and childcare settings-2026

• Provides practical advice for headteachers and caretakers on how to manage existing ventilation systems, monitor CO2 levels, and use air cleaning units to maintain a healthy learning environment post-pandemic.

Building Regulations Part F on ventilation

• This is a statutory regulation that sets minimum ventilation requirements for all buildings in England, including schools. It aims to ensure that buildings have adequate ventilation to maintain indoor air quality.

Health and Safety at Work Act 1974

• HSWA is the primary health and safety law in Great Britain. Even though it does not mention indoor air quality explicitly, it creates a legal duty for schools (as employers) to ensure that the working environment, including air quality, is safe for staff, pupils, and visitors.

COSHH Regulations-1992

• The Control of Substances Hazardous to Health Regulations 2002 (COSHH) place a legal duty on schools, as employers, to prevent or control exposure to hazardous substances that could harm staff or pupils. This includes airborne contaminants that affect IAQ.

4. IAQ management strategies

Ventilation

• A range of ventilation strategies can be adopted. These range from a completely natural system to a mechanical system. If the mechanical or hybrid ventilation is opted for, then providing quality HVAC should be prioritised for clean and healthy IAQ in schools. Systems which are properly maintained provide adequate ventilation, reducing pollutants that cause most IAQ issues inside school buildings.

Monitoring

• Even though there are currently no requirements to routinely monitor air quality in schools, this is essential to ensure the school environment is healthy, to reduce absenteeism and improve performance. If you don’t know what is there, how can you manage it?

Training

• According to Building Bulletin 101, explicit training is required on the operation of ventilation systems for the facilities management team, particularly if the system is complex or BMS-controlled. For other school staff, basic training is also required.

Source control

• This is one of the most effective and low-cost ways to improve IAQ. Choose products that have less of an effect on human health and the environment.

Conclusion

Indoor air quality in schools has a strong influence on children’s health, with profound evidence from organisations such as the World Health Organisation, the UK Health Security Agency and the Royal College of Paediatrics and Child Health, showing that exposure to indoor pollutants increases respiratory problems, asthma exacerbations, and susceptibility to infections.

Beyond the immediate health implications, IAQ also has a great impact on educational performance, demonstrating that certain pollutants impair cognitive functions, including attention, working memory, and processing speed, which translate into lower test performance, increased fatigue among pupils and staff, etc., undermining the learning environment.

Given the evidence, it can be concluded that IAQ is not only a public health priority but also a critical component of educational and school performance. Addressing and preventing IQA issues through a structured management programme is vital, by incorporating regular monitoring, effective ventilation practices, source control of pollutants, staff training and routine review, to help identify risks early and maintain healthier learning environments.

At Assurity Consulting, we’ve been providing independent assessments of IAQ and wider aspects, such as lighting and noise for nearly 40 years and in workplace ranging from offices and data centres to schools. How might you benefit your school environment?

Assurity Consulting is the UK’s leading independent consultancy specialising in workplace health, safety and environmental solutions. As your partner in compliance management you will reap the benefit of our more than 40 years’ experience of helping customers across a range of different sectors – manage their compliance responsibilities as effectively as possible. If you need any help with your health, safety or environmental compliance, or if you would like more information on the services Assurity Consulting offer, please get in touch.

DOWNLOAD PDF