Indicator air

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).

Assessment of the state
poor poor
Assessment of the trend
unsatisfactory unsatisfactory
rural 2024: 3.92357017400147 rural 2023: 4.625 rural 2022: 4.5790648165917 rural 2021: 4.58469612508783 rural 2020: 5.35931133315178 rural 2019: 5.55982485722518 rural 2018: 5.89677736932967 rural 2017: 4.59923377602916 rural 2016: 4.31875 rural 2015: 4.91508864906021 rural 2014: 4.2875 rural 2013: 3.92902370591763 rural 2012: 4.45393570415837 rural 2011: 5.15856068018996 rural 2010: 4.41844859896392 rural 2009: 4.72123423152881 rural 2008: 4.21291518523989 rural 2007: 4.41904094108676 rural 2006: 4.92373113271368 rural 2005: 4.50899158861437 rural 2004: 4.48021746501602

Data for the graph: Excel
Source: FOEN: NABEL

Source: FOEN
Comment

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.

Method

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.

Basis for assessment of the trend
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.

 
Last updated on: 30.06.2025

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