PM2.5 in the UK

December 2010


Background to research

It is recognised that exposure to airborne particulate matter (PM) can give rise to significant health effects and there is no evident safe level. Attention was initially directed towards PM of less than 10 mm diameter (PM10), but epidemiological evidence regarding the health effects of smaller particles has now changed the focus to smaller particles less than 2.5 mm diameter (PM2.5). As a consequence, new legislation has recently come into effect to control exposure to PM2.5 (with a continuation of controls on PM10), and the United Kingdom (UK)Government will need to develop approaches to reduce exposure to PM2.5. To ensure this is carried out in the most cost-effective way it is first necessary to have a good understanding of the sources, pathways and health effects of PM2.5, and of the legislation that can contribute to its control. The focus is on annual mean concentrations of PM2.5, as these are the most significant in terms of health outcomes, and on concentrations within urban areas, where most people are exposed.

Objectives of research
This SNIFFER project is designed to provide regulators with an understanding of PM2.5, including health effects, sources, speciation, pathways, regulatory requirements, monitoring and modelling tools. It will be used to advise regulators on how PM sources need to be regulated to achieve the air quality limit values and objectives.

Key findings and recommendations

Sources and behaviour of PM2.5
Exposure to PM2.5
Health effects of PM2.5
Legislation to control exposure to PM2.5
Measurements of PM2.5 concentrations

1There is one site, Harlington, officially classified as "Airport", however this is around 1 km from Heathrow Airport, and as such, PM2.5 concentrations will be affected by the airport to a very limited extent. It is thus better to treat this site as an urban background site for PM2.5

Modelling of PM2.5
Policy implications

Key words: PM2.5, health effects, ambient, emissions, sources, concentrations, legislation, monitoring, modelling.

Copies of this report are available from the Foundation, in electronic format on CDRom at £20.00 + VAT or hard copy at £50 00, less 20% to FWR members.

N.B. The report is available for download from the SNIFFER Website