• Issue
• Background
• Activities
• Further information

Issue

Agricultural practices can potentially affect air quality through the emission of nitrogen compounds, particulate matter, and other substances.

Background

Agricultural emissions of nitrogen compounds may have negative effects on ecosystems. Nitrogen compounds emitted from agricultural sources can impact air quality, the most significant of which are ammonia (NH3), primarily from fertilizers and livestock, and nitrogen oxides (NOx) from fuel combustion in farm equipment. In fact, the draft Canadian National Inventory of Ammonia Emissions shows that agricultural activities are the primary source of ammonia in the air.

Quantities of ammonia from agricultural sources:

• increased by an estimated 2.5 times, mainly due to increases associated with livestock, between 1980 and 1995; and
• represented 95% of all ammonia emissions from human sources and 56% of total emissions, human and natural, estimated for 1995.

Smog

Some agricultural activities also play a large role in the formation of smog - a noxious mixture of air pollutants that can often be seen as a haze in the air. The two main components of smog are airborne particulate matter and ground-level ozone.

Airborne particulate matter consists of microscopic material in the air. These tiny particles, capable of being inhaled by humans, pose a significant threat to human health. In fact, respiratory particulate matter has been declared toxic by the Canadian Environmental Protection Act (CEPA) due to its possible danger to human life, health and the environment.

In agriculture, ammonia emissions from fertilizers and livestock are the key producers of fine particulate matter. Dust from the cultivation of agricultural land and soil erosion is responsible for a large portion of the coarse particulate matter in the air, which causes haze and visibility problems. This environmental problem has declined with the increasing adoption of agricultural practices such as conservation tillage.

Ground level ozone is formed from NOx and volatile organic compounds (VOCs) in the presence of sunlight. Projections in the NOx/VOCs Management Plan show NOx from agricultural vehicles increasing in relative significance as a source in the transportation sector.

Odour

Odour, particularly from manure produced by intensive livestock operations, is an increasing public concern. For example, odour in agricultural areas with significant non-farming populations is leading to difficulties in obtaining municipal approval to build high volume hog barns. Odour is generally regarded as a nuisance rather than an environmental issue. However, there may also be some negative health effects from exposure to high concentrations of certain components of odour, such as ammonia, particularly for agricultural workers.

Activities

AAFC initiatives to address air quality issues include programs, such as the Canadian Adaptation and Rural Development Program (CARD), Agri-Environmental Indicator Project, the Agricultural Environmental Stewardship Initiative (AESI) and the Livestock Environmental Initiative (LEI), as well as collaborative, multi-stakeholder efforts to establish and promote standards and best management practices to improve air quality. The Bureau closely monitors and directly participates in the various initiatives designed to manage agricultural and other sources of air pollutants.

Agriculture and Agri-Food Canada's Research Branch is working hard to develop ways to reduce the adverse impact of agricultural practices on air quality. For example, scientists at the Dairy and Swine Research and Development Centre in Sherbrooke, Quebec have developed an anaerobic treatment system that uses biotechnology to deodorize and stabilize swine manure slurry. Other studies examine the loss of nitrogen during manure composting. Retaining more nitrogen in the composting of manure will result in a higher value product, reduced air pollution, better working environments and reduced corrosion in composting facilities and equipment.

Concerns about the environmental and human health effects resulting from emissions of various pollutants has led to a number of domestic and international initiatives to determine the need for systematic and targeted management of these air emissions. The key initiatives are:

• the Protocol to Abate Acidification, Eutrophication and Ground Level Ozone under the Convention on Long Range Transboundary Air Pollution (LRTAP) of the United Nations Economic Commission for Europe (UNECE);
• the National Acid Rain Strategy, under the Federal and Provincial Ministers of Environment and Energy (FPMEE);
• the National Smog Management Plan, also under the FPMEE: and
• the Canada-Wide Standards for Particulate Matter and Ozone, under the Canadian Council of Ministers of the Environment (CCME)

In Canada, measures to manage atmospheric emissions of potentially harmful substances, including those from agricultural sources, are administered largely at the provincial and local levels of government and therefore vary according to jurisdiction. Outside Canada, national programs under the CCME and the FPMEE will provide the basis for Canadian positions at international negotiations. For example, under the UNECE Long-Range Transboundary Air Pollution (LRTAP) Convention Canada cooperates with the United States on the transboundary transport of nitrogen oxides (NOx), ozone and particulate matter. Under the Canada/US Air Quality Agreement, binational commitments exist on NOx.

Further Information

Contacts within the Environment Bureau:
Isabelle Proulx (Air Emissions)

Related documents

Hardcopy publications are available by contacting:
e-mail: comeau@agr.gc.ca
telephone: (613) 759-6610/6626
fax: (613) 759-6726
mailing address:

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