Ammonia immissions
Excessive concentrations of ammonia (NH3) lead to acidification and eutrophication of ecosystems. Additionally, ammonia is an important precursor in the formation of secondary particulate matter. It mainly comes from animal production (stables, slurry storage and spreading of farm manure).
poor
unsatisfactory
Ammonia pollution has hardly changed over the last ten years and remains significantly above the critical values according to the Convention on Long-range Transboundary Air Pollution (1 µg/m3 for lichens and mosses, 3 µg/m3 for ecosystems with vascular plants). Ammonia concentration is particularly high at sites with intensive livestock farming. To reach an acceptable level in the coming years, ammonia pollution would need to decrease much more significantly than it has so far. For this reason, the development is considered unsatisfactory.
- Related indicators
- Ammonia emissions
- Übermässiger Stickstoffeintrag
The concentration of gaseous ammonia (NH3) in the air is determined by means of passive diffusion samplers. The gas is absorbed on an acid-treated filter, and converted thereby into ammonium. The quantity of ammonium retained by the filter can be determined in the laboratory by means of ion chromatography, from which the ammonia concentration can be calculated.
| Targeted trend | Initial value | Final value | Variation in % | Observed trend | Assessment |
|---|---|---|---|---|---|
| Decrease | Average 2004-2006 | Average 2022-2024 | -5.64% | Decrease | Unsatisfactory* |
*Due to the small number of measuring stations and the influence of weather conditions, it is difficult to make a statement about the trend.
Further information
