Molecular formula: PM2.5, PM10
Characteristics: Fine particles with a diameter of less than 10 micrometres (one thousandth of a millimetre) bind to other dangerous chemicals such as lead or inorganic salts.
Occurrence: Particulate matter arises from fires, transport, or combustion at factories. In households, the source can be a furnace, gas cooker, or candle. Risks are also posed by dust whirls (mining, building industry).
Impact: Particulate matter can get into the lower airways, windpipe, and air sacs, thereby harming the cardiovascular and respiratory systems. Moreover, it irritates the mucous membrane of the respiratory tract, reduces its self-cleaning ability, and thus makes the development of an infection easier. Particulate matter contributes to the incidence of cancer.
Limit: The maximum safe concentration is, according to the WHO, an annual average of 10 µg/m3 for PM2.5, while for PM10 it is 20 µg/m3.