"Emission" means the release of a substance from a point or diffuse source into the atmosphere.  Definitions of pollutants are provided in paragraph 7 and 8 of the reporting guidelines (Reporting Guidelines 2023).

Main components: 

• SO_x – Sulphur oxides reported as SO₂
• NO_x – Nitrogen oxides reported as NO₂
• NH₃ – Ammonia
• NMVOC – Non-methane volatile organic compounds
• CO – Carbon monoxide

Particulate matter (PM): 

• PM₁₀ – Particulate matter with diameter equal to or less than 10 µm
• PM_2.5 – Particulate matter with diameter equal to or less than 2.5 µm
• TSP – Total Suspended Particulates
• BC – Black Carbon which means carbonaceous particulate matter that absorbs light

Heavy metals (HMs): 

• Cd – Cadmium and its compounds
• Hg – Mercury and ist compounds
• Pb – Lead and its compounds
• As – Arsenic and its compounds
• Cr – Chromium and its compounds
• Cu – Copper and its compunds
• Ni – Nickel and its compounds
• Se – Selenium and its compounds
• Zn – Zinc and it compounds

Persistent organic pollutants (POPs):

• PCDD /PCDF – Dioxins and Furans
• PAHs –  Polyaromatic hydrocarbons {benzo(a)pyrene, benzo(b)fluoranthene, benzo(k) fluoranthene, indeno(1,2,3-cd)pyrene, total 1-4}
• HCBs – Hexachlorobenzene (CAS: 118-74-1)
• PCBs – Polychlorinated biphenyls