Particulate matter (PM10, PM2.5)


  • solid and liquid particles of varying dimensions (aerodynamic diameter of less than 10 micrometres for PM10 and less than 2.5 micrometres for PM2.5) and composition: heavy metals, sulphate, nitrate, ammonium mineral constituents, elemental and organic carbon as for example polycyclic aromatic hydrocarbons, dioxins and furans
  • a complex mixture of solid particles and liquid droplets consisting of both primary particles emitted by a direct source and secondary particles formed by natural and anthropogenic sources such as soot, geological material, abrasion particles and biological material

Main sources

  • motorised road transport (combustion processes, abrasion)
  • rail transport (abrasion)
  • agriculture and forestry (combustion processes)
  • industry, commerce (production processes)
  • construction sites (combustion processes, mechanical processes)
  • furnaces, particularly those that use wood as fuel
  • secondary formation from sulphur dioxide, nitrogen oxides, ammonia and volatile organic compounds

Thresholds for the reporting requirement of facilities in accordance with Annex 2 PRTRO

For PM10 according to annex 2 of the PRTRO (Ordinance on the Register relating to Pollutant Release and the Transfer of Waste and of Pollutants in Waste Water)

  • Air               50'000 kg/year
  • Water           -
  • Soil               -


  • respiratory, heart and circulatory system diseases
  • increased mortality and cancer risk
  • soil, plant and human contamination by heavy metals and dioxins and furans (contained in dust)

Ambient limit values

20 µg/m3        Annual average (arithmetic mean)
50 µg/m³     24-hour mean; must not be exceeded more than three times per year

10 µg/m3     Annual average (arithmetic mean)  

Status and changes

Particulate matter concentrations have decreased significantly since 1991. The decrease may be attributable on the one hand to the reduction of secondary particles (especially sulphate) and to the reduction of primary particle emissions on the other. Particulate matter concentrations have decreased further since 2000. Years 2003 and 2006 were exceptions. Frequent inversions in the Northern Alps caused higher concentrations in those years. Winter inversions are a very strong cause of peak particulate matter levels. They prevent air exchange and lead to high concentrations of particulate matter at ground level.


Last modification 30.10.2019

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