Mineral dust
Air quality mineral aerosol
Mineral dust consists of small particles of soil, sand, rock or mineral building materials. It may be lifted locally or transported over long distances.
Not a single substance
The term describes the material’s origin. A particle may come from dry soil, crushed rock or building material. Wind, traffic and construction lift such particles into the air. Some settle quickly, while finer particles can remain airborne longer.
Dust and particulate matter overlap
Mineral dust describes composition; PM10 and PM2.5 describe size ranges. A mineral particle can also belong to PM10. Particulate matter additionally includes soot, salts and organic material, so the terms are not interchangeable.
When the Sahara lands on a car
Suitable air currents can carry North African dust to central Europe. When rain deposits it, visible traces may remain on cars and windows. That does not make every dusty windscreen a sample from the Sahara; there are plenty of closer sources.
The dust layer’s height matters
An elevated dust layer can haze the sky without raising surface exposure by the same amount. AOD describes light attenuation through the air column; surface dust concentrations may use µg/m³. Current particle measurements and their averaging periods are more useful for health assessment than the colour of the sky.