Abstract
Children in the UK spend around 30% of their week at school, with 70% of that time being spent indoors studying and engaging in various activities. In schools maintaining good indoor environmental quality (IEQ), especially indoor air quality (IAQ) and thermal comfort is essential. These elements are interconnected and collectively shape the indoor space, by providing clean air and comfortable temperatures to support children’s health, attendance, productivity, well-being and learning. Yet, thousands of schools in England (~7,800) are located in areas with high levels of air pollution that exceed the WHO guidelines, highlighting the need for effective measures to protect students and staff from exposure to air pollutants, and the importance of considering interventions to improve the environment around schools, including transport-related measures.
Exposure to indoor air pollution can impact learning, academic development and school attendance during the school years. Poor indoor air quality, inadequate ventilation, high levels of CO2 and uncomfortable thermal conditions can affect pupils' concentration, academic performance, attendance, and overall comfort. It also increases the risk of developing asthma and respiratory problems in young children. This is particularly concerning in the UK, which has the highest prevalence of childhood asthma in Europe (14%), compared to the lowest in Greece (4%). Creating healthy classroom environments through effective management of indoor environmental conditions is therefore essential to promote efficient learning, enhance performance, reduce absenteeism, and protect children’s long-term health. However, school buildings are complex spaces to design, deliver and operate because of their health/well-being requirements and the need to balance indoor air quality, ventilation performance and thermal conditions.
Achieving adequate IAQ and thermal comfort in classrooms can be challenging, particularly in naturally ventilated buildings where conditions vary with weather (e.g. indoor and outdoor temperature and air density), occupant behaviours (e.g. adaptive actions such as opening a window, increased student mobility in classrooms as a result of curriculum demand), activities (e.g. science vs singing), building-related options (e.g. natural vs mechanical ventilation) and green infrastructure (e.g. hedges or green screen) installed alongside school boundaries. Ventilation remains one of the most effective strategies to maintain adequate IAQ, but it should be carefully managed, as it may not always improve IAQ as expected. In areas with high outdoor air pollution, outdoor air may introduce traffic-related air pollutants and allergens (e.g. tree/grass pollen) into the classroom.
A balanced approach that combines effective ventilation with measures such as air purifiers, appropriate building materials, green infrastructure, strategic classroom layout, and the use of low-cost air quality sensors for assessing pollutant levels is therefore needed to create healthier learning environments and reduce exposure to indoor air pollutants. A strategic approach to improving IEQ in schools is essential to protect children’s health, support learning and reduce exposure to air pollution and airborne infection risks. Existing official guidance, including the US EPA Reference Guide for Indoor Air Quality in Schools, UK DfE ventilation and air quality guidance and allergy safety guidance, and BB10130 provide principles and compliance frameworks (i.e. benchmark values, pollutant concentration thresholds and ventilation principles) for managing IAQ and ventilation in schools. This guide complements existing statutory and technical guidance and is presented as a practical companion, translating classroom-specific frameworks and evidence into a simple, actionable “how-to” guide for school classrooms.
This guide builds on previous work conducted in and around schools and draws on the team’s extensive experience in producing guidance for the public and practitioners (e.g. pioneering guidance on green infrastructure implementation and general recommendations for source control and IEQ management). It sets out ten specific ways to help schools reduce air pollution exposure and improve IEQ, translating current scientific evidence into practical recommendations that can be applied in school settings. These recommendations are based on scientific evidence drawn from multiple peer-reviewed publications. Owing to a lack of data on the relative effects of each influencing activity, these recommendations are not presented in any specific order of importance, impact, or priority. In any case, addressing poor environmental quality in classrooms requires a comprehensive strategy. The distinctiveness of this document lies in its co-created and co-designed practical approach, which targets schools as a key setting for protecting and promoting children’s health.
The guide uses a clear and accessible structure to support its practical use. It is aimed primarily at schools and teachers, and secondarily at councillors, local authorities, and government departments. It is designed to help each stakeholder develop the areas within their responsibility, address their specific needs, and navigate complex discussions by providing concise checklists and practical recommendations.