Overview - Ammonia

Ammonia

Ammonia (NH₃) in the atmosphere results primarily from the decomposition and volatilisation of animal wastes. As such it is in principle a natural trace gas. However, as agricultural livestock numbers have dramatically increased, together with increases in nitrogen fertilization NH₃ emissions have increased accordingly (Sutton et al. 1993). Even if only the trends in animal numbers are accounted for, NH₃ emissions are estimated to have at least doubled over the last century across Europe (Asman et al. 1988). The largest increases have occurred for the pig and poultry livestock sectors - with in the case of poultry a six fold increase for the UK between 1860 and 1980. Long term measurement records, such as of precipitation chemistry, confirm these increases (Sutton et al. 1993), and suggest that intensification has resulted in even larger increases in NH₃ emissions than predicted according to animal numbers. Other sources of ammonia emission include direct volatilisation from mineral fertilizers (particularly urea), agricultural crops and a wide range of non-agricultural sources including sewage, catalytic converters, wild animals, seabirds and industrial processes (Sutton et al. 1995, 2000).

Total ammonia emissions in the UK are currently estimated at 283 kt N yr^-1 (Sutton et al. 2000) with 228 kt from agricultural sources (Pain et al. 1998). The estimated spatial distribution of NH₃ emissions in the UK is shown below (Dragosits et al. 1998).

Atmospheric ammonia has impacts on both local and international (transboundary) scales. In the atmosphere ammonia reacts with acid pollutants such as the products of SO₂ and NO_X emissions to produce fine ammonium (NH₄⁺) containing aerosol. While the lifetime of NH₃ is relatively short (<10-100 km), NH₄⁺ may be transferred much longer distances (100->1000 km) (Asman et al. 1998, Fowler et al. 1998). Hence NH₃ emissions contribute to international transboundary air pollutant issues addressed by the UNECE Convention on Long Range Transboundary Pollution.

In addition to the transboundary effects, NH₃ has substantial impacts at a local level: emissions occur at ground level in the rural environment and NH₃ is rapidly deposited (see Nitrogen deposition). As a result some of the most acute problems of NH₃ deposition are for small relict nature reserves located in intensive agricultural landscapes (Sutton et al. 1998).

Asman W.A.H., Drukker B. and Janssen A.J. (1988): Modelled historical concentrations and depositions of ammonia and ammonium in Europe. Atmospheric Environment 22: 725-735.

Asman W.A.H., Sutton M.A. and Schjoerring J.K. (1998): Ammonia: emission, atmospheric transport and deposition. New Phytologist 139, 27-48.

Dragosits U., Sutton M.A., Place C.J. and Bayley A. (1998): Modelling the spatial distribution of ammonia emissions in the UK. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 195-203.

Fowler D., Sutton M.A., Smith R.I., Pitcairn C.E.R., Coyle M., Campbell G. and Stedman J. (1998): Regional mass budgets of oxidized and reduced nitrogen and their relative contribution to the N inputs of sensitive ecosystems. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 337-342.

Pain B.F., van der Weerden T.J., Chambers B.J., Phillips V.R. and Jarvis S.C. (1998): A new inventory for ammonia emissions from U.K. agriculture. (Ammonia Special Issue) Atmospheric Environment 32 (3), 309-313.

Sutton M.A., Pitcairn C.E.R. and Fowler D. (1993): The exchange of ammonia between the atmosphere and plant communities. Advances in Ecological Research 24, 301-393.

Sutton M.A., Place C.J., Eager M., Fowler D. and Smith R.I. (1995): Assessment of the magnitude of ammonia emissions in the United Kingdom. Atmospheric Environment 29, 1393-1411.

Sutton M.A., Milford C., Dragosits U., Place C.J. Singles R.J., Smith R.I., Pitcairn C.E.R., Fowler D., Hill J., ApSimon H.M., Ross C., Hill R., Jarvis S.C., Pain B.F., Phillips V.C., Harrison R., Moss D., Webb J., Espenhahn S.E., Lee D.S., Hornung M., Ullyett J., Bull K.R., Emmett B.A., Lowe J. and Wyers G.P. (1998): Dispersion, deposition and impacts of atmospheric ammonia: quantifying local budgets and spatial variability. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 349-361.

Sutton M.A., Dragosits U., Tang Y.S. and Fowler D. (2000): Ammonia emissions from non-agricultural sources in the UK. Atmospheric Environment 34 855 - 869.



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Ammonia Ammonia (NH₃) in the atmosphere results primarily from the decomposition and volatilisation of animal wastes. As such it is in principle a natural trace gas. However, as agricultural livestock numbers have dramatically increased, together with increases in nitrogen fertilization NH₃ emissions have increased accordingly (Sutton et al. 1993). Even if only the trends in animal numbers are accounted for, NH₃ emissions are estimated to have at least doubled over the last century across Europe (Asman et al. 1988). The largest increases have occurred for the pig and poultry livestock sectors - with in the case of poultry a six fold increase for the UK between 1860 and 1980. Long term measurement records, such as of precipitation chemistry, confirm these increases (Sutton et al. 1993), and suggest that intensification has resulted in even larger increases in NH₃ emissions than predicted according to animal numbers. Other sources of ammonia emission include direct volatilisation from mineral fertilizers (particularly urea), agricultural crops and a wide range of non-agricultural sources including sewage, catalytic converters, wild animals, seabirds and industrial processes (Sutton et al. 1995, 2000). Total ammonia emissions in the UK are currently estimated at 283 kt N yr^-1 (Sutton et al. 2000) with 228 kt from agricultural sources (Pain et al. 1998). The estimated spatial distribution of NH₃ emissions in the UK is shown below (Dragosits et al. 1998). Atmospheric ammonia has impacts on both local and international (transboundary) scales. In the atmosphere ammonia reacts with acid pollutants such as the products of SO₂ and NO_X emissions to produce fine ammonium (NH₄⁺) containing aerosol. While the lifetime of NH₃ is relatively short (<10-100 km), NH₄⁺ may be transferred much longer distances (100->1000 km) (Asman et al. 1998, Fowler et al. 1998). Hence NH₃ emissions contribute to international transboundary air pollutant issues addressed by the UNECE Convention on Long Range Transboundary Pollution. In addition to the transboundary effects, NH₃ has substantial impacts at a local level: emissions occur at ground level in the rural environment and NH₃ is rapidly deposited (see Nitrogen deposition). As a result some of the most acute problems of NH₃ deposition are for small relict nature reserves located in intensive agricultural landscapes (Sutton et al. 1998).
		Impacts of NH₃ include: soil and freshwater acidification eutrophication of oligotrophic ecosystems with consequent species loss aerosol production affecting global radiative forcing (the 'greenhouse effect') increases in emissions of the greenhouse gases nitrous oxide (N₂O) and methane (CH₄) modification of the transport and deposition patterns of SO₂ and NO_x. Emission abatement of NH₃ is currently being negotiated within the EU Acidification Strategy and the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP). Abatement of NH₃ emissions is also included in Integrated Pollution Prevention and Control (IPPC) for the intensive pig and poultry sectors. Other information: CEH Ammonia monitoring network http://www.cara.ceh.ac.uk
References: Asman W.A.H., Drukker B. and Janssen A.J. (1988): Modelled historical concentrations and depositions of ammonia and ammonium in Europe. Atmospheric Environment 22: 725-735. Asman W.A.H., Sutton M.A. and Schjoerring J.K. (1998): Ammonia: emission, atmospheric transport and deposition. New Phytologist 139, 27-48. Dragosits U., Sutton M.A., Place C.J. and Bayley A. (1998): Modelling the spatial distribution of ammonia emissions in the UK. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 195-203. Fowler D., Sutton M.A., Smith R.I., Pitcairn C.E.R., Coyle M., Campbell G. and Stedman J. (1998): Regional mass budgets of oxidized and reduced nitrogen and their relative contribution to the N inputs of sensitive ecosystems. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 337-342. Pain B.F., van der Weerden T.J., Chambers B.J., Phillips V.R. and Jarvis S.C. (1998): A new inventory for ammonia emissions from U.K. agriculture. (Ammonia Special Issue) Atmospheric Environment 32 (3), 309-313. Sutton M.A., Pitcairn C.E.R. and Fowler D. (1993): The exchange of ammonia between the atmosphere and plant communities. Advances in Ecological Research 24, 301-393. Sutton M.A., Place C.J., Eager M., Fowler D. and Smith R.I. (1995): Assessment of the magnitude of ammonia emissions in the United Kingdom. Atmospheric Environment 29, 1393-1411. Sutton M.A., Milford C., Dragosits U., Place C.J. Singles R.J., Smith R.I., Pitcairn C.E.R., Fowler D., Hill J., ApSimon H.M., Ross C., Hill R., Jarvis S.C., Pain B.F., Phillips V.C., Harrison R., Moss D., Webb J., Espenhahn S.E., Lee D.S., Hornung M., Ullyett J., Bull K.R., Emmett B.A., Lowe J. and Wyers G.P. (1998): Dispersion, deposition and impacts of atmospheric ammonia: quantifying local budgets and spatial variability. Environmental Pollutution (Nitrogen Conference Special Issue). 102, S1, 349-361. Sutton M.A., Dragosits U., Tang Y.S. and Fowler D. (2000): Ammonia emissions from non-agricultural sources in the UK. Atmospheric Environment 34 855 - 869.
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