The numbers of premature deaths attributed to air pollution are not routinely estimated on a weekly basis. It is not possible to identify individual patients affected by air pollution. The link between air pollution and deaths brought forward is derived from statistical correlations between daily air pollution levels and routine daily statistics on total deaths.
Air pollution is associated with adverse health effects. An assessment carried out for the review of the air quality strategy1 estimated that the level of man-made particulate air pollution experienced in the UK in 2005 would be expected to reduce average life expectancy by up to about eight months. This health impact in 2005 is estimated to cost up to £9 billionto £21.4 billion per annum. Road transport will contribute to these effects.
Ozone and particulate matter are long-range pollutants which may travel hundreds of miles before reaching the UK. Particulate matter does have a local component, and local road transport contributes a proportion of this. For ozone, local road transport emissions actually reduce peak levels in cities due to the destruction of ozone in reaction with vehicle emissions.
The Department of Health's Committee on Medical Effects of Air Pollutants (COMEAP) quantification sub-group, in its report The quantification of the effects of air pollution on health in the United Kingdom, estimated in 19982 the number of deaths brought forward due to short-term exposure to particulate matter (PM10), ozone and sulphur dioxide as up to 24,000 per year.
Assuming that around a quarter of the PM103 in urban areas is due directly or indirectly to emissions from transport, as a rough estimate it can be assumed that up to around 2,000 deaths brought forward in urban areas may have been related to emissions from transport at that time.
This estimate does not include the impact of transport emissions on life expectancy and on cardiovascular admissions. These were not quantified by COMEAP at the time of the 1998 report. Further work on this issue is likely to be considered as part of the work of the COMEAP sub-group on quantification.
Estimates are made for intense pollutionepisodes. For example, an estimate was made for the summer smog episode in August 20034. Some 220 to 570 deaths were estimated to have been brought forward over the two-week period due to ozone and a further 202 due to particulate matter (PM10). A report and estimate is also being produced on the summer smog episodes during the June and July 2006 heatwave. This will be available in due course.
1 Defra (2006) The Air Quality Strategy for England, Scotland, Wales and Northern Ireland—volume 1. A consultation document for further improvements in air quality.
2 Based on pollution levels in 1996. Pollution levels have reduced substantially since then.
3 This includes PM10 derived directly from road, rail, aircraft and ships and PM10 derived indirectly from NOx transport emissions from the UK and Europe. It excludes sources such as coarse dust, sea salt, and emissions from industry.
4 Stedman, J.R., (2003) The predicted number of air pollution related deaths in the UK during the August 2003 heatwave. Atmospheric Environment.