Consists of the build-up of fine solid particles or droplets of liquids in the ambient atmosphere, generated by an anthropogenic activity.

• PM= PM10 + PM2.5 + Other larger particles.
• PM10: Particulate matter that passes through a size-selective inlet as defined in the EN 12341 standard, with a 50% efficiency cut-off at 10 µm aerodynamic diameter.
• PM2,5: Particulate matter that passes through a size-selective inlet as defined in the EN 14907 standard, with a 50% efficiency cut-off at 2.5 µm aerodynamic diameter.