Summary of issue
Exposure to air pollutants can have both acute and chronic health effects, from mild to severe, with many pollutants not perceived by occupants. Indoor air quality is to a large extent dependent on outdoor air pollution; in addition, the indoor environment contains many sources of air pollutants from building materials, consumer products, occupants and their activities.
- The likelihood and severity of effects of exposure to air pollutants depends on age, any pre-existing medical conditions and individual sensitivity. The effects also include temporary discomfort and annoyance (or pleasure) from odours, and negative impacts from some pollutants on cognitive performance.
- Building occupants are constantly exposed to numerous substances from multiple sources. Most assessments evaluate risks on a substance-by-substance basis and do not consider the combined adverse health effects due to exposure to multiple pollutants.
- There is currently no comprehensive regulatory framework on indoor air quality, and poor implementation of the limited guidelines related to pollutant levels given in Building Regulations Approved Document F.
- The UK’s ambient air quality objectives do not align with the World Health Organization (WHO) for certain pollutants, with WHO guidelines being more stringent.
- There is a lack of guidance on procedures and equipment for indoor air quality monitoring.
CIBSE considers that there are important gaps in the mix of regulations, knowledge, skills and solutions that are needed to deliver and maintain healthy indoor environments, considered as part of a holistic approach to building performance. Current Building Regulations Approved Document F only addresses ventilation, without sufficient consideration of factors such as outdoor pollutants. It also has an incomplete approach to sources of indoor air pollution, as it is mainly concerned with moisture and combustion products from heating equipment and cooking appliances. There is an additional concern that buildings with particularly low (i.e. good) airtightness, may not be adequately ventilated.
More comprehensive and better enforced regulations would assist in developing a market for solutions such as low-emission building materials and reliable but accessible monitoring equipment, which could ultimately be of benefit in all buildings.
CIBSE also considers that there should be a firm commitment to align ambient air quality objectives with World Health Organization and Public Health England guidelines, with clear mechanisms to review and report on progress.
A whole system approach is crucial, for example considering the effect of transport emissions on buildings and their occupants.
The following measures should be adopted to deliver good indoor air quality and limit negative impacts on outdoor air quality:
- Avoiding or, where not possible, reducing, exposure to sources of pollution, including through planning of the site and building layout and the location of air intakes.
- Minimising emissions of pollutants e.g. selecting materials and equipment with low emission rates.
- Providing adequate fresh air supply rates.
- Implementing filtration and purification if required.
- Ensuring good installation, commissioning, cleaning and maintenance of ventilation systems.
- Carrying out as-built tests and, where possible, on-going monitoring of key pollutants.
- CIBSE Guide A: Environmental Design
- CIBSE Guide B: Heating, Ventilation and Air Conditioning Systems
- TM40: Health and wellbeing in building services
- TM21 Minimising Pollution at Air Intakes
- Working with WELL: Using the WELL Building tool in the UK (Air)
Date approved by Technology Committee: March 2020