Fine particles

The term PM – Particulate Matter – refers to a collection of solid and liquid particles suspended in the air that we breathe. The dangerous particles for our health are those with a diameter of less than 10 microns (PM10) which can be inhaled.

The PM comprises different chemical substances: heavy metals, hydrocarbons, nitrates, sulphates. This toxic mix spreads through the organism via the blood system, causing cardiovascular illnesses, inflammations of respiratory pathways and tumours (source: World Health Organisation).

PM emission sources
The particulate matter can be generated by natural sources (volcanic ash, desert sand, marine aerosol) and by anthropic sources including  traffic, especially that relative to diesel engines, constituting the greatest source of pollution (about 65% of PM present in the air in inhabited areas, source: Ministry of the Environment).