Effects of agriculture on air quality in Canada

Abstract

The modernization of animal production as well as demographic changes in rural areas has resulted in difficult cohabitation problems in some regions of Canada. This chapter focuses on three predominant air quality issues associated with modern farming: odour, particulate matter and ammonia. Odour can adversely affect quality of life, lead to socio-emotional nuisances and cause genuine physical symptoms. Odours are mainly associated with confined animal farming operations, especially exhaust from animal housing, storage of animal wastes, application of manure to land. Particulate matter (PM) is now well known to be potentially toxic to humans. Agricultural PM is emitted from soil erosion tillage and livestock buildings. Ammonia contributes somewhat to odour but more importantly reacts in the atmosphere to form fine secondary particulates, also a potential health concern. Ammonia is emitted from livestock wastes (especially urine and uric acid) and from urea or ammonia containing fertilizers. Ammonia in the particulate form travels long distances and can damage certain plant communities and ecosystems. Good farming practices often reduce impact on air quality: examples include precise feeding of protein which reduced excretion of urea, injection of manure and fertilizer, and reduced tillage and summerfallow in crop production which reduces PM. In some cases, to reduce complaints, it may be necessary to regulate separation in space or time between the public and farming operations.