Exposure to air pollution by particulate matter (source: EEA)

The indicator measures the population weighted annual mean concentration of particulate matter at urban background stations in agglomerations. Fine and coarse particulates (PM10), i.e. particulates whose diameters are less than 10 micrometers, can be carried deep into the lungs where they can cause inflammation and exacerbate the condition of people suffering heart and lung diseases. Fine particulates (PM2.5) are those whose diameters are less than 2.5 micrometers. They are therefore a subset of the PM10 particles. Their deleterious health impacts are more serious than PM10 as they can be drawn further into the lungs and may be more toxic.