|Nitrogen oxides (Nox)
||Combustion of motor spirit and other fuel, combustion for domestic heating, power stations, industrial boilers, chemical processes etc.
||Road transport 44% Power stations 21% Other industry 9%
||Fuel combustion for power stations, domestic heating, industrial boilers, diesel vehicles, waste incinerators.
||Power stations 65% Other industry 10% Refineries 8%
||Combustion of motor spirit and other combustion processes.
||Road transport 69% Off-road sources 9% Domestic 5%
||Secondary pollutant resulting from chemical reactions with nitrogen oxides and VOCs.
||See NOx & VOCs.
||Fuel combustion for power stations, transport, heating, other industrial processes.
||Construction, mining, quarrying 13% Road transport 20% Power stations 10% Domestic 20%
|Volatile Organic Compounds (VOCs)
||Transport, oil combustion, chemical processes, solvent use, waste incinerators.
||Road transport 27% Solvent use 27% Extraction & distribution of fossil fuels 15% Production processes 12%
||Combustion of motor spirit, evaporation from petrol pumps and fuel tanks.
||Road transport 71%
||Combustion of leaded petrol, coal combustion, metal production.