PM2.5 has now been added to our bulletin and episodes pages, allowing users to select just PM2.5 sites, and to see the value of PM2.5 at a site where it is recorded. No index is shown for PM2.5 beacuse it is not included in the current UK Air Quality Information System and therefore we do not have ‘low’, ‘moderate’, ‘high’ or ‘very high’ bands for this pollutant. Instead we are showing the latest measurement in micrograms per metre cubed (ug/m3). We will update this when a UK index is defined for PM2.5.
Particulates - Larger particles in the atmosphere are generally filtered in the nose and throat and do not cause problems, but particulate matter smaller than about 10 micrometers, referred to as PM10, can settle in the bronchi and lungs and cause health problems. Particles smaller then 2.5 micrometers, referred to as PM2.5, can penetrate the smallest airways and are often associated with man made sources.
The effects of inhaling particulate matter have been widely studied in humans and animals and include asthma, respiratory problems and cardiovascular issues.

Item date 10/01/2011