The graph above shows the emissions of primary PM10 particles (particulate matter with a diameter of 10µm or less, emitted directly into the atmosphere) and secondary particulate-forming pollutants (the fraction of sulphur dioxide, SO2, nitrogen oxides NOx and ammonia NH3 which, as a result of photo-chemical reactions in the atmosphere, transform into particulate matter with a diameter of 10µm or less)

References and footnotes