What is PM10?
PM10 is the concentration of airborne particles smaller than 10 micrometres, measured in micrograms per cubic metre of air. It describes the air near the ground, where we breathe, so it relates directly to air quality and to visibility in cities and on roads. It counts all airborne particles, not dust alone.
How to read the colours
The scale at the bottom of the map starts at 100 µg/m³ in pale yellow, moves through orange to red at 600 to 1000, and ends in purple at 2000 and above. Dark areas with no colour are below the start of the scale. The stronger the colour, the more likely poor visibility and effects on people with allergies or asthma. Labels inside the image are in Arabic.