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 Printable version |
Atmospheric quality around animal buildings |
Cahiers Agricultures. Volume 7, Number 5, 377, Octobre-Novembre 1998, Synthèse
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 Résumé
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Author(s) : Alfred Marquis, Philippe Marchal |
Summary : Atmospheric emissions from animal production units can occur in the form of gases, solids, airborne particles and dust, odors and noise. The main gases emitted from farm buildings and known for their potentially detrimental or hazardous effects on the atmosphere are: ammonia (which contributes to the acid-precipitation cycle), carbon dioxide and methane (which are known to be involved in climate change). Airborne particles can act as carriers of gases (some odorous compounds), micro-organisms, water vapour and other substances. Nuisances are detected through sensations (human physiological reactions) and have effects on human well-being. Dust particles, odours and noise are generally classified in this category.
Aerial pollutants and nuisances are emitted in the atmosphere around animal buildings through ventilation systems, or by waste storage facilities which are generally not covered. The marked expansion and concentration of animal units and the switch to liquid manure handling at many units has led to more complaints concerning air pollution and nuisances. Rules and legislation have been passed in most countries that provide incentives for the development of methods to control and reduce emissions. Gas pollutants travel on long distances and are regulated by international conventions, particularly those drawn up to control acid precipitation and climate change.
In recent years, there has been a substantial increase in research activities aimed at enhancing the overall understanding of mechanisms involved in the emission and dispersion of aerial pollutants and nuisances around animal buildings. Techniques to control emissions at the source are more readily accepted by farmers. They also generally bring benefits by improving air quality inside buildings, thus improving animal performance and behavior and conditions for the well-being and health of farm workers. Biofilters, which are effective for reducing some gases or odours from ventilation systems, are too costly to be accepted by producers. This is also the case concerning effective covering of manure stores, which is only carried out when stipulated by government regulations.
There are many parameters involved with respect to the emission of pollutants and nuisances, thus explaining the wide variations noted in research results. This also applies for control strategies, making technological design choices relatively difficult. Most of these technologies are energy-consuming and increase farmers’ expenses. However, they are needed to promote sustainable animal production and maintain good relationships between different stakeholders in rural areas. |
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