Changes (%) in emissions of acidifying pollutants by source category, 1990-2007, EEA-27 (weighted by acid equivalency factors)

The figure shows the emissions of acidifying pollutants (sulphur dioxide SO2, nitrogen oxides NOx and ammonia NH3) each weighted by an acid equivalency factor prior to aggregation to represent their respective acidification potentials. The acid equivalency factors are given by: w(SO2) = 2/64 acid eq/g = 31.25 acid eq/kg, w(NOx) = 1/46 acid eq/g = 21.74 acid eq/kg and w(NH3) = 1/17 acid eq/g = 58.82 acid eq/kg.