Table 1.

The specific apportionment of PM factors according to their size and physical and chemical properties. Based on Fierro – “Particulate Matter” 2000 [23, 24]

Classification	Symbol	Diameter	Major source	Potential lifetime of PM	Potential travel distance of PM
Coarse particles	PM10	From 2.5 μm to 10 μm	Air pollutants originated from urban, industrial, traffic and agricultural sources	From minutes to hours	from < 1 km to 10 km
Fine particles	PM2.5	Less than 2.5 μm	Air pollutants originated from long-range transport geogenic soil particles, anthropogenic emissions from steel factories, road traffic and industry emissions	From days to weeks	From 100 km to more than 1000 km