Agriculture
Agricultural activities can potentially affect air quality through the emission of nitrogen compounds, particulate matter, and other substances.
Importantly, agricultural activities are the main source of ammonia (NH3) in air, which mainly comes from livestock and the use of fertilizers. In addition, the operation of farm equipment such as tractors and other machinery releases the many pollutants associated with the combustion of fuels, including nitrogen oxides (NOx). Even the turning or tilling of soils, especially in dry, windy conditions, contributes to higher levels of particulate matter (PM) within the air.
Visit the Agriculture Canada Air Site for more information.