Layers: 
Annual mean nitrogen dioxide 2012, based on daily average with percentage of valid measurements ≥ 75 % in µg/m³(0)
Annual mean nickel 2012, based on annual average with percentage of valid measurements ≥ 14 % in µg/m³(1)
Annual mean arsenic 2012, based on annual average with percentage of valid measurements ≥ 14 % in µg/m³(2)
Annual mean cadmium 2012, based on annual average with percentage of valid measurements ≥ 14 % in µg/m³(3)
Annual mean lead 2012, based on annual average with percentage of valid measurements ≥ 14 % in µg/m³(4)
Annual mean benzo(a)pyrene 2012, based on annual average with percentage of valid measurements ≥ 14 % in µg/m³(5)
93.2 percentile of ozone concentration in 2012, based on daily running 8h max with percentage of valid measurements ≥ 75 % in µg/m³(6)
Annual mean ozone 2012, based on daily running 8h max with percentage of valid measurements ≥ 75 % in µg/m³(7)
Annual mean benzene 2012, based on annual average with percentage of valid measurements ≥ 50 % in µg/m³(8)
Annual mean carbon monoxide 2012, based on daily running 8h max with percentage of valid measurements ≥ 75 % in µg/m³(9)
Annual mean particulate matter < 2.5 µm (aerosol) 2012, based on daily average with percentage of valid measurements ≥ 75 % in µg/m³(10)
90.4 percentile of particulate matter < 10 µm (aerosol) concentration in 2012, based on daily average with percentage of valid measurements ≥ 75 % in µg/m³(11)
Annual mean particulate matter < 10 µm (aerosol) 2012, based on daily average with percentage of valid measurements ≥ 75 % in µg/m³(12)
Annual mean sulphur dioxide 2012, based on daily average with percentage of valid measurements ≥ 75 % in µg/m³(13)
