National Air Pollutant Emissions

Air pollution problems such as smog and acid rain result from the presence of, and interactions between various air pollutants that are released into the atmosphere. These air pollutants are released through human activities such as transportation (e.g., cars, trucks), burning fuels for electricity and heat production, industrial processes, and the use of certain products (i.e., paints and solvents). They are also released through natural sources such as forest fires and vegetation.

Air pollutant emissions indicators track emissions from human-related sources of sulphur oxides (SO_x), nitrogen oxides (NO_x), volatile organic compounds (VOC), ammonia (NH₃), carbon monoxide (CO), total particulate matter (TPM), respirable particulate matter (PM₁₀)and fine particulate matter (PM_2.5). The emissions for these key air pollutants are retrieved from the Air Pollutant Emission Summaries and Trends compiled by the National Pollutant Release Inventory (NPRI), Canada's legislated, publicly accessible inventory of pollutant releases.

In 2010, emission levels of most key air pollutants were 18–57% lower than in 1990; only ammonia (NH₃) emissions were 10% higher than the 1990 emission levels.

Air pollutant emissions, Canada, 1990 to 2010

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., road dust) are not included, except for ammonia (NH₃), where agricultural sources have been included in the indicator.
Source: Environment Canada (2012) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends.

Overview of sources of air pollutant emissions

In 2010, industrial activities and home firewood burning emitted most of the particulate matter (TPM, PM₁₀ and PM_2.5) released in Canada. The majority of Canada’s SO_x emissions came from the use of fuels for electricity and heating, industrial activities such as non-ferrous smelting and refining, and the oil and gas industry.

Transportation released the largest proportion of Canada’s NO_x and CO emissions. The oil and gas industry and off-road vehicles were other important sources of NO_x emissions. Off-road vehicles were another important source of CO emissions. Most of Canada’s VOC emissions came from the oil and gas industry and from the use of paints and solvents. Finally, agricultural activities were the main source of ammonia emissions in Canada.

Distribution of air pollutant emissions by source, Canada, 2010

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., road dust) are not included, except for ammonia (NH₃), where agricultural sources have been included in the indicator.
Source: Environment Canada (2012) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends.

Overview of air pollutant emissions by province and territory

The three provinces with the highest emission levels in 2010 were Alberta, Quebec and Ontario. Of the provincial emission levels for SO_x, NO_x, VOC and NH₃, Alberta’s were highest, mainly due to the oil and gas industry for SO_x, NO_x and VOC and to agriculture for NH₃. Quebec’s particulate matter emissions (TPM, PM₁₀ and PM_2.5) were highest because of home firewood burning in the province. Ontario’s CO emission levels were the highest among provinces, mainly because of high emissions from transportation.

Distribution of air pollutant emissions by province and territory, Canada, 2010

Note: Emissions from natural sources (e.g., forest fires) and open sources (e.g., road dust) are not included, except for ammonia, where agriculture sources have been included in the indicator.
Source: Environment Canada (2012) National Pollutant Release Inventory: Air Pollutant Emissions Summaries and Trends. 

Details on national air pollutant emissions

• Sulphur oxides (SO_x)  
• Nitrogen oxides (NO_x)
• Volatile organic compounds (VOC)
• Ammonia (NH₃)
• Carbon monoxide (CO) 
• Particulate matter (TPM, PM₁₀, and PM_2.5) 

Related indicators

• International Comparison: Air Pollutant Emissions