PURPOSE AND SCOPE OF THIS GUIDANCE

This guidance is intended to assist with the development of ventilation strategies to minimise the ingress of external pollutants into non-domestic urban buildings. It provides a methodology for doing this, together with fundamental information on urban air pollution in relation to buildings, including the following topics.

• Common urban air pollutants which are mostly covered by the Air Quality Strategy for England, Scotland, Wales and Northern Ireland^[1] namely,

• carbon monoxide (CO)

• nitrogen dioxide (NO₂)

• sulfur dioxide (SO₂)

• ozone (O₃)

• particles (PM₁₀)

• benzene (C₆H₆)

• 1,3-butadiene (C₄H₆)

• lead (Pb)

• polycyclic aromatic hydrocarbons (PAHs) (eg benzo[alpha]pyrene (B[alpha]P)

• nitric oxide (NO)

• Nuisance contaminants such as dust and odour, in brief

• Sources of urban air pollutants

• Contributions of the pollutants from the sources to the exposure of buildings and occupants

• UK Air Quality Strategy and Objectives

• Methods for estimating internal concentrations of external pollutants

• Guidance on ventilation strategies for minimising levels of the external pollutants in indoor air

This guidance concentrates on non-domestic buildings in urban areas since these contain the highest density of buildings and population, and hence usually the highest external pollution loads. However, the same principles can also be applied to domestic buildings and those in more open environments, where conditions are usually less severe but an assessment of the quality and ingress of external air may still be desired. Furthermore, while this guidance has been written primarily with regard to buildings in the UK using relevant UK data sources, it can equally be applied to buildings in other countries by using appropriate data sources.

This guidance does not override the usual requirements of providing adequate ventilation for occupant respiration, diluting occupant-generated carbondioxide, removing other internally generated pollutants and controlling humidity. Its concern is with the additional internal pollutant burden that may result from external pollutant sources.