Health Effects of Particles
Information on effects
Health Effects
PM10 is a descriptive term for small particles that are 10 microns or less in diameter. Generally speaking particles greater in size than 10 microns are too large be taken into the lungs as the natural defences of the body, such as the nasal hair, will prevent inhalation. The NAQS cites evidence that suggests PM10s have been associated with deaths from heart and lung disease. These deaths occur mainly amongst the elderly which indicates that exposure to PM10s can cause premature death in vulnerable groups. Studies have shown that such deaths occur some days later than recorded peak concentrations so the effects of exposure is not instantaneous. Other evidence has shown that prolonged exposure to PM10s can increase the likelihood of developing lung cancer and also result in other lung and heart diseases.
Sources
There are natural and human sources for particle matter. Natural sources include sea salt, pollen and fungal spores. The activities of humans that give rise to PM10 include road transport, quarrying, and industrial activity. In Hammersmith & Fulham the single biggest source of PM10 is road transport which accounts for an estimated 77% of total emissions.
Standard
The air quality standard to be achieved by the year 2005 is set at 50 ug/m3 or less as the 99th percentile of daily maximum running 24 hour means. This means that for 99% of the time the recorded concentration should be below 50 micrograms per cubic metre of air. This is to permit occasional exceedances such as bonfire night when levels of particles are high.
Monitoring results
There has been no historic measurement of PM10 in the borough, however the new air quality station situated at Hammersmith Broadway measures for PM10 on a continuous basis. The station has only been operating for limited period of time and the information obtained so far can only provide an indication as to the current levels of particles in the borough. Monitoring across London indicates that exceedences occur on a regular basis.
Compliance with the standard.
The DETR's guidance on the first stage review states that areas on a 1 km square basis that give rise to emissions in excess of 10 tonnes per annum are likely to give rise to exceedences. The LRC's emission inventory shows that a large area of the borough generates levels in excess of this guide. This and the information on traffic movements in the borough suggest that further assessment of particles needs to be undertaken.
