Air pollutant emissions

Note: n/a = not available. The percentages have been rounded off and their sum may not add up to 100.

Note: The percentages have been rounded off and their sum may not add up to 100.

Sulphur oxide emissions by source

Emissions of sulphur oxides (SO_X) to the atmosphere can result in adverse effects on human health and the environment. The SO_X emissions released by human activities are mostly in the form of sulphur dioxide (SO₂). Sulphur dioxide can affect the respiratory systems of humans and animals and can cause damage to vegetation, buildings and materials. It also contributes to the formation of fine particulate matter (PM_2.5) and acid rain.

Key results

• In 2024,
  • SO_X emissions were 545 kilotonnes (kt), which is 81% lower than in 1990
  • the oil and gas industry, the ore and mineral industries and electric utilities accounted for 92% (503 kt) of the total SO_X emissions

Total sulphur oxide emissions by source, Canada, 1990 to 2024

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How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from transportation (road, rail, air and marine), off-road vehicles and mobile equipment, home firewood burning, incineration and waste, agriculture (livestock, crop production and fertilizer), dust and fires, paints and solvents, building heating and energy generation, manufacturing, and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, the oil and gas industry accounted for approximately 42% of total national SO_X emissions (232 kt). The ore and mineral industries and electric utilities followed with 30% (163 kt) and 20% (109 kt) of national emissions, respectively. For the ore and mineral industries, 36% (59 kt) of its SO_X emissions came from the non-ferrous refining and smelting industry and 39% (63 kt) came from the aluminum industry.

The largest reduction in emissions between 1990 and 2024 was from the ore and mineral industries with a reduction in emissions of approximately 1,247 kt. The largest driver of the reduction from this source was from the non-ferrous refining and smelting industry with a reduction of 1,206 kt over the period.

This significant decrease in SO_X emissions from 1990 to 2024 (81%) is due in large part to government actions to fight acid rain and related federal-provincial and Canada-United States agreements^{Footnote 1 Footnote 2} on capping SO_X emissions by 1994.

Further reductions were also realized through:

• technological upgrades, new air pollution controls for non-ferrous metal smelters and the closure of 4 major smelters in Manitoba, Ontario, Quebec and New Brunswick
• improved technologies used in fossil-fuel-fired (such as, coal-fired) power-generating utilities, as well as plant closures (for example, the phase-out of coal electricity generation in Ontario and Alberta)
• implementation of regulations on low-sulphur fuels^{Footnote 3 Footnote 4}

More recently, between 2023 and 2024, SO_X emissions have declined due to decreases in emissions from the electric utilities industry of 26 kt (19%), largely driven by reduced use of coal power plants and increased use of cleaner fuels.

Sulphur oxide emissions by province and territory

Key results

• In 2024, Alberta and Saskatchewan accounted for 26% (141 kt) and 21% (112 kt) of national SO_X emissions
• Between 1990 and 2024,
  • the largest reductions in emissions were observed in Ontario and Manitoba. Emissions in these provinces decreased by 976 kt (91%) and 507 kt (99.6%), respectively
  • Saskatchewan was the only province that had an increase in SO_X emissions (4% or 5 kt)

Sulphur oxide emissions by province and territory, Canada, 1990, 2005 and 2024

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How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

Alberta was the highest emitter of SO_X in 2024, accounting for 26% (141 kt) of total national emissions. Emissions in the province mainly came from the oil and gas industry, accounting for 91% (129 kt) of its emissions. Between 2005 and 2024, overall emissions in the province declined by 69% (317 kt). A large part of this reduction came from the oil and gas industry, particularly from natural gas processing, oil sands mining extraction and processing and petroleum refining.

Saskatchewan was the second-highest emitter of SO_X in 2024, accounting for 21% (112 kt) of total national emissions. Emissions from electric utilities, specifically coal electric power generation, was the largest contributor to SO_X emissions in the province, accounting for 60% (68 kt) of the emissions.  

Ontario was the third highest emitter of SO_X, with 17% (93 kt) of total national emissions. The ore and mineral industries sector was the largest source of emissions in the province in 2024, accounting for 70% (65 kt) of the province’s SO_X emissions.

Sulphur oxide emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.^{Footnote 5}

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore SO_X emissions from individual facilities.

Key results

• In 2024, 2,432 facilities across Canada reported SO_X emissions representing 94% of total national emissions. Of these facilities:
  • 2,025 facilities reported emissions under 25 tonnes (t)
  • 389 facilities reported emissions between 25 to 6,000 t
  • 18 facilities reported emissions of 6,000 t or more located in Quebec (5), Ontario (3), Alberta (3), Saskatchewan (3), Nova Scotia (2), Newfoundland and Labrador (1) and British Columbia (1)

Sulphur oxide emissions by reporting facilities, Canada, 2024

Source: Environment and Climate Change Canada (2026) National Pollutant Release Inventory.
Navigate data using the interactive map

Nitrogen oxide emissions by source

Nitrogen oxides (NO_X) include nitric oxide (NO) and nitrogen dioxide (NO₂). Nitrogen dioxide can have adverse effects on human health and the environment. Nitrogen oxides contribute to acid rain, which can lead to the acidification of aquatic and terrestrial ecosystems. It also contributes to the eutrophication of lakes and to the formation of ground-level ozone (O₃) and fine particulate matter (PM_2.5).

Key results

• In 2024,
  • NO_X emissions were 1,205 kilotonnes (kt); this is 46% lower than in 1990
  • the oil and gas industry was the largest source of NO_X, representing 37% (447 kt) of total NO_X emissions

Total nitrogen oxide emissions by source, Canada, 1990 to 2024

Download data file (Excel/CSV; 4 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from ore and mineral industries, manufacturing, building heating and energy generation, home firewood burning, incineration and waste, agriculture (livestock, crop production and fertilizer), dust and fires, paints and solvents, and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

The oil and gas industry was the largest contributor of NO_X emissions in 2024, representing 37% (447 kt) of total national emissions. Emissions of NO_X from this sector increased by 103 kt (30%) between 1990 and 2024.

The transportation (road, rail, air and marine) sector was the second largest contributor of NO_X emissions in 2024, representing 25% (302 kt) of total national emissions. This sector also showed the largest decrease in emissions (592 kt or 66%) between 1990 and 2024.

The decline in NO_X emissions between 1990 and 2024 is mostly attributable to 2 factors:

• the reduction in emissions from transportation after 2000 due to the progressive introduction of cleaner technology and fuels for vehicles as a result of the implementation of federal regulations that set air pollution standards for vehicles and their engines
• lower emissions from fossil-fuel-fired (for example, coal-fired) power-generating utilities as a result of better emission control technologies and certain plant closures (for example, the closure of coal power plants in Ontario)

More recently, between 2023 and 2024, NO_X emissions have declined due to decreases in emissions largely from off-road vehicles and mobile equipment (10 kt, 6%) and electric utilities (9 kt, 10%). However, NO_X emissions from transportation (road, rail, air and marine) sources have increased by 4 kt (1%), notably from domestic marine navigation and rail transportation.

Nitrogen oxide emissions by province and territory

Key results

• In 2024, Alberta had the highest NO_X emissions among all provinces and territories. The province accounted for 42% (504 kt) of national emissions
• Between 1990 and 2024,
  • the largest reduction was observed in Ontario. Emissions decreased by 414 kt (70%) in the province
  • NO_X emissions increased in Northwest Territories and Nunavut by 103% (11 kt)^{Footnote 6}  

Nitrogen oxide emissions by province and territory, Canada, 1990, 2005 and 2024

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How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

The oil and gas industry is an important source of NO_X emissions in Alberta, accounting for 69% (349 kt) of the province's NO_X emissions in 2024. The increasing contribution of this sector to the province's emissions between 1990 and 2024 was more than offset by emission reductions from the transport and electric utilities sectors.

Ontario and British Columbia contributed the second and third largest proportions of NO_X emissions in 2024, with Ontario accounting for 15% (176 kt) and British Columbia accounting for 14% (167 kt). The transportation (road, rail, air and marine) sector was the major source in both provinces, followed by the oil and gas industry in British Columbia and off-road vehicles and mobile equipment in Ontario. However, Ontario experienced the largest decrease in emissions (70% or 414 kt) between 1990 and 2024 in large part due to emission reductions from transportation (road, rail, air and marine), electric utilities, off-road vehicles and mobile equipment, manufacturing and the ore and mineral industries. In Ontario, the majority of total NO_X emission reductions occurred between 2005 and 2024 (362 kt).

Quebec ranked fourth, with 10% (123 kt) of total national emissions. Transportation (road, rail, air and marine) was the major source of NO_X emissions in this province. Quebec also experienced a large decrease in emissions (56% or 159 kt) between 2005 and 2024 mainly due to emission reductions from transportation (road, rail, air and marine).

Nitrogen oxide emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore NO_X emissions from individual facilities.

Key results

• In 2024, 3,616 facilities across Canada reported NO_X emissions representing 41% of total national emissions. Of these facilities:
  • 2,180 facilities reported emissions under 50 tonnes (t)
  • 1,327 facilities reported emissions between 50 to 800 t
  • 109 facilities reported emissions of 800 t or more located in Alberta (42), Ontario (15), Quebec (12), British Columbia (11), Saskatchewan (7), Newfoundland and Labrador (7), Nova Scotia (5), New Brunswick (4), Northwest Territories (3) and Nunavut (3)

Nitrogen oxide emissions by reporting facilities, Canada, 2024

Source:  Environment and Climate Change Canada (2026) National Pollutant Release Inventory.
Navigate data using the interactive map

Volatile organic compound emissions by source

Volatile organic compounds (VOCs) are carbon-containing gases and vapours released into the atmosphere by natural sources and human activities.^{Footnote 7} There are hundreds of VOCs that are emitted and that affect the health of people living in Canada and the environment. VOCs are primary precursors to the formation of ground-level ozone and particulate matter, which are the main pollutants contributing to the formation of smog.

Key results

• In 2024, VOC emissions in Canada were 1,358 kilotonnes (kt); this is a 38% (840 kt) decrease from 1990 levels
• Since 1990, the oil and gas industry has been the highest contributor to VOC emissions; in 2024 the sector accounted for 40% (546 kt) of total emissions

Total volatile organic compound emissions by source, Canada, 1990 to 2024

Download data file (Excel/CSV; 4 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from incineration and waste, ore and mineral industries, dust and fires, building heating and energy generation, electric utilities and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

Apart from the oil and gas industry, paints and solvents, manufacturing and off-road vehicles and mobile equipment were also important sources of VOC emissions in 2024, contributing 19% (258 kt), 9% (116 kt) and 9% (116 kt) of total emissions, respectively.

The largest emissions reduction between 1990 and 2024 was from the transportation (road, rail, air and marine) sector, with emissions reductions of 280 kt (81%).

The long-term decrease in VOC emissions is mainly attributable to 3 factors:

• the progressive introduction of cleaner technologies and fuels resulting in emission reductions from transportation, off-road vehicles and mobile equipment
• emission reductions from most industrial and non-industrial sources from facility closures, decrease in production and improved emission controls
• lower levels of VOCs in products such as paints, solvents and cleaners

Compared to the previous year, VOC emissions increased by 5 kt (0.4%) in 2024. The largest increase was from the oil and gas industry 12 kt (2%), notably light medium crude oil production, which accounted for 39% of the overall oil and gas sector’s increase (4 kt). 

Volatile organic compound emissions by province and territory

Key results

• Alberta emitted the highest proportion of VOCs in 2024, representing 35% (482 kt) of national emissions
• Between 1990 and 2024,
  • Ontario experienced the largest reduction in VOC emissions with a decrease of 316 kt (54%)
  • Saskatchewan was the only province that experienced an increase in VOC emissions, rising by 14 kt (8%), primarily due to changes in emissions from the oil and gas industry

Volatile organic compound emissions by province and territory, Canada, 1990, 2005 and 2024

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How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

Alberta was the highest emitting province of VOCs in 2024, contributing 35% of national emissions (482 kt). The oil and gas industry was the main source, contributing 74% (356 kt) of the province's emissions.

Ontario was the second-highest emitter of VOCs, accounting for 20% (274 kt) of total national emissions in 2024. The main emission sources were paints and solvents, off-road vehicles and mobile equipment, and manufacturing. Ontario also experienced the largest reduction in emissions, amounting to 316 kt (54%) between 1990 and 2024, mainly as a result of emission reductions from manufacturing and transportation (road, rail, air and marine). The majority of the reductions in Ontario occurred between 2005 and 2023 (296 kt).

Saskatchewan was the third largest emitter of VOCs, accounting for 14% (191 kt) of total national emissions in 2024. The oil and gas industry accounted for 73% (139 kt) of the emissions in this province.

Volatile organic compound emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore VOC emissions from individual facilities.

Key results

• In 2024, 4,578 facilities across Canada reported VOC emissions representing 19% of total national emissions. Of these facilities:
  • 2,937 facilities reported emissions under 15 tonnes (t)
  • 1,558 facilities reported emissions between 15 to 400 t
  • 83 facilities reported emissions of 400 t or more located in Alberta (36), Ontario (18), Saskatchewan (7), Quebec (7), Manitoba (4), New Brunswick (3), Newfoundland and Labrador (3), British Columbia (3), Nova Scotia (1) and Northwest Territories (1)

Volatile organic compound emissions by reporting facilities, Canada, 2024

Navigate data using the interactive map

Source:  Environment and Climate Change Canada (2026) National Pollutant Release Inventory.

Ammonia emissions by source

Ammonia (NH₃) is a colourless gas with a noticeable odour at high concentrations. It can be poisonous if inhaled in great quantities and is irritating to the eyes, nose and throat. It can also contribute to the nitrification and eutrophication of aquatic systems. In the air, the gas combines with sulphates and nitrates to form secondary fine particulate matter (PM_2.5).

Key results

• In 2024,
  • NH₃ emissions were 506 kilotonnes (kt), which is 28% higher than in 1990
  • agriculture (livestock, crop production and fertilizer) was the main source of NH₃ emissions, accounting for 94% (474 kt) of total national emissions

Total ammonia emissions by source, Canada, 1990 to 2024

Download data file (Excel/CSV; 3 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from incineration and waste, the oil and gas industry, home firewood burning, the ore and mineral industries, electric utilities, building heating and energy generation, off-road vehicles and mobile equipment, dust and fires, paints and solvents, and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, emissions from manufacturing (11 kt), other sources (14 kt) and transportation (road, rail, air and marine) (7 kt) combined represented 6% of national emissions.

Between 1990 and 2024, the agriculture (livestock, crop production and fertilizer) sector experienced the largest increase (118 kt or 33%) in NH₃ emissions. It also remained the key source of NH₃ emissions throughout that period. The growth in NH₃ emissions from agriculture (livestock, crop production and fertilizer) between 1990 and 2024 is mainly due to the increased use of synthetic nitrogen fertilizers in crop production. Up to 2005, increasing livestock populations also added to the growth in NH₃ emissions. However, from 2006 to 2011, livestock populations decreased and NH₃ emissions from that source have since declined slowly. More recently, emissions from crop production have been steadily increasing since 2006.^{Footnote 8}

Ammonia emissions by province and territory

Key results

• In 2024, Alberta and Saskatchewan accounted for over half (256 kt) of national NH₃ emissions
• Between 1990 and 2024,
  • Ontario experienced the largest emissions reduction with 16 kt (15%)
  • the largest increase in NH₃ emissions was in Saskatchewan with emissions more than doubling (a 66 kt increase)
  • Alberta and Manitoba also showed increases in NH₃ emissions of 46 kt (48%) and 23 kt (61%), respectively

Ammonia emissions by province and territory, Canada, 1990, 2005 and 2024

Download data file (Excel/CSV; 2 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, Alberta emitted the most NH₃ among all provinces and territories, accounting for 28% (141 kt) of total national emissions. Saskatchewan contributed the second-largest proportion of NH₃, representing 23% (115 kt) of total national emissions. Ontario followed with 19% (95 kt) of total national emissions in 2024. Livestock farms and the application of fertilizers were the most important sources of NH₃ emissions in Alberta, Saskatchewan and Ontario.

Almost all of the increase in national emissions between 1990 and 2024 took place in Saskatchewan, Alberta and Manitoba.

Ammonia emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore NH₃ emissions from individual facilities.

Key results

• In 2024, 301 facilities across Canada reported NH₃ emissions representing 4% of total national emissions. Of these facilities:
  • 198 facilities reported emissions under 25 tonnes (t)
  • 95 facilities reported emissions between 25 to 400 t
  • 8 facilities reported emissions of 400 t or more, located in Alberta (5), British Columbia (1), Manitoba (1) and Saskatchewan (1) 

Ammonia emissions by reporting facilities, Canada, 2024

Source: Environment and Climate Change Canada (2026) National Pollutant Release Inventory.
Navigate data using the interactive map

Carbon monoxide emissions by source

Carbon monoxide (CO) is a colourless, odourless, tasteless and poisonous gas. Once inhaled into the bloodstream, it can inhibit the blood's capacity to carry oxygen to organs and tissues, affecting human health and wildlife.

Key results

• In 2024,
  • CO emissions in Canada were 4,390 kilotonnes (kt), a decrease of 66% from 1990 levels
  • the off-road vehicles and mobile equipment sector was the largest source of CO emissions in Canada, representing 36% (1,599 kt) of total emissions
  • the transportation (road, rail, air and marine) sector was the second largest source, representing 23% (1,016 kt) of CO emissions in Canada

Total carbon monoxide emissions by source, Canada, 1990 to 2024

Download data file (Excel/CSV; 4 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from dust and fires, electric utilities, building heating and energy generation, incineration and waste, agriculture (livestock, crop production and fertilizer), paints and solvents, manufacturing and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, transportation, off-road vehicles and mobile equipment were the 2 most important sources of CO. These sources combined represented 60% (2,615 kt) of national emissions.

The largest reduction in emissions between 1990 and 2024 occurred in the transportation (road, rail, air and marine) sector with an emission decrease of 5,090 kt (83%).

The decline in CO emissions between 1990 and 2024 was mainly due to increasingly stringent engine and vehicle regulations and the progressive introduction of cleaner and more efficient technology in vehicles (for example, catalytic converters). 

Carbon monoxide emissions by province and territory

Key results

• In 2024, Quebec, Alberta and Ontario accounted for 71% (3,118 kt) of national CO emissions
• Between 1990 and 2024,
  • all provinces and territories experienced reductions in emissions
  • the largest reductions occurred in Ontario (2,635 kt or 74%), British Columbia (1,822 kt or 78%), Quebec (1,355 kt or 54%) and Alberta (1,273 kt or 56%)

Carbon monoxide emissions by province and territory, Canada, 1990, 2005 and 2024

Download data file (Excel/CSV; 2 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, Quebec emitted the most CO among all provinces and territories, representing 27% (1,165 kt) of total national emissions. The ore and mineral industries sector was the largest contributor to CO emissions in Quebec, representing 32% (372 kt) of the province’s total emissions. Within this sector, the aluminum industry accounted for 91% (339 kt) of emissions in Quebec.

Alberta had the second highest emissions in 2024, with 23% (1,019 kt) of total national emissions. Of these emissions, 78% (796 kt) came from 2 sources: off-road vehicles and mobile equipment (38% or 387 kt) and the oil and gas industry (40% or 409 kt).

Ontario, the third largest CO emitter, accounted for 21% (933 kt) of total national emissions. The off-road vehicles and mobile equipment and the transportation sectors accounted for 41% (382 kt) and 35% (329 kt) of the province's CO emissions, respectively.

The sharp decrease in emissions between 1990 and 2024 in all provinces and territories is mainly attributable to emission reductions from transportation (road, rail, air and marine), largely driven by improvements in fuel efficiency. Some of the largest reductions occurred between 2005 and 2024, notably for Ontario, with emissions decreasing by 1,536 kt (62%).

Carbon monoxide emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore CO emissions from individual facilities.

Key results

• In 2024, 3,429 facilities across Canada reported CO emissions representing 19% of total national emissions. Of these facilities:  
  • 1,574 facilities reported emissions under 25 tonnes (t)
  • 1,775 facilities reported emissions between 25 to 1,000 t
  • 80 facilities reported emissions of 1,000 t or more, located in Alberta (28), Quebec (19), Ontario (15), British Columbia (7), New Brunswick (5), Saskatchewan (2), Newfoundland and Labrador (2), Manitoba (1) and Nova Scotia (1) 

Carbon monoxide emissions by reporting facilities, Canada, 2024

Navigate data using the interactive map

Source: Environment and Climate Change Canada (2026) National Pollutant Release Inventory.

Fine particulate matter emissions by source

Particulate matter (PM) is directly emitted into the air in solid or liquid form. It is also formed in the air from precursor substances such as sulphur oxides, nitrogen oxides, volatile organic compounds and ammonia.^{Footnote 9} Fine particulate matter (PM_2.5) refers to particulate matter with a size of less than 2.5 micrometres (also called microns). It is one of the major components of smog. When inhaled, PM_2.5 can travel deeply into the lungs and lead to the onset or development of negative health effects. Even small amounts of PM_2.5 can cause serious health problems. It can also damage vegetation and structures, contribute to haze and reduce visibility.

Key results

• In 2024,
  • PM_2.5 emissions were 1,126 kilotonnes (kt); this is 22% lower than in 1990
  • emissions from dust and fires (for example, road dust, dust from construction operations and prescribed burning^{Footnote 10} ) accounted for the majority of PM_2.5 emissions, reaching 56% (630 kt) of total national emissions
    • these emissions increased by 79% (278 kt) between 1990 and 2024; dust from construction operations, specifically non-residential construction, and unpaved roads accounted for the majority of the increase

Total fine particulate matter emissions by source, Canada, 1990 to 2024

Download data file (Excel/CSV; 5 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires and from vegetation. The category "other sources" includes emissions from ore and mineral industries, transportation (road, rail, air and marine), manufacturing, off-road vehicles and mobile equipment, the oil and gas industry, building heating and energy generation, electric utilities, incineration and wastes, paints and solvents, and other miscellaneous sources. Consult Table 1 in the Data sources and methods for a complete list of the air pollutant emissions sources included under each category. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, 86% of PM_2.5 emissions came from open source emissions, such as dust and fires and agriculture (livestock,^{Footnote 11} crop production and fertilizer). The PM_2.5 emissions data does not include emissions from natural sources such as wildfires and vegetation. In general, these open source emissions are spread over large geographical areas, are highly dependent on weather conditions (for example, wind and rain) and are located outside of urban areas, where an estimated 25% of the population lives.^{Footnote 12} As such, for most people in Canada, exposure to PM_2.5 is not driven by emissions from open sources, but rather from direct emissions from other sources and from PM_2.5 that forms when pollutants react in the atmosphere.

The remaining 14% of PM_2.5 emissions in 2024 came from home firewood burning (48 kt or 4%) and other sources, including:

• ore and mineral industries, representing 3% (30 kt) of the emissions
• manufacturing and miscellaneous sources, such as emissions from commercial cooking, each representing about 1% (15 kt and 16 kt, respectively) of emissions
• off-road vehicles and mobile equipment, representing about 1% (14 kt) of emissions
• the oil and gas industry, representing about 1% (13 kt) of emissions
• transportation (road, rail, air and marine), representing less than 1% (8 kt) of emissions
• other emissions (less than 1%; 7 kt) coming from building heating and energy generation, electric utilities, incineration and waste, and the use of paints and solvents

Many of the sources above, despite representing a small proportion of national emissions, can have a disproportionate health impact on the population because they are generally concentrated in or near populated areas.

The decreases in PM_2.5 emissions between 1990 and 2024 are mainly attributable to emission reductions from agriculture (crop production) (332 kt or 49%), manufacturing (99 kt or 87%) and home firewood burning (54 kt or 53%). These reductions outweigh the increase in emissions from dust and fires (278 kt or 79%), specifically road dust and dust from construction operations, over the same period. The adoption of conservation practices in crop production and the use of new fireplace inserts, furnaces and stoves that burn more efficiently to control emissions from home firewood burning were the main drivers leading to the reductions.

Fine particulate matter emissions by province and territory

Key results

• In 2024, Alberta had the highest PM_2.5 emissions, representing 25% (279 kt) of total national emissions
• Between 1990 and 2024,
  • the largest decrease was observed in Saskatchewan, with a reduction of 191 kt (43%)
  • PM_2.5 emissions increased by 6 kt (4%) in Quebec, 1 kt (40%) in Yukon and 5 kt (154%) in Northwest Territories and Nunavut combined

Fine particulate matter emissions by province and territory, Canada, 1990 and 2024

Download data file (Excel/CSV; 2 KB)
How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only, including open sources. It does not include emissions from natural sources such as forest fires and from vegetation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, Alberta had the highest PM_2.5 emissions among all provinces and territories, accounting for 25% (279 kt) of total national emissions. Agriculture (specifically wind erosion) and dust and fires (specifically dust from non-residential construction and unpaved roads) were the largest sources of PM_2.5 emissions in the province.

Saskatchewan ranked second in 2024, with 22% (249 kt) of total national PM_2.5 emissions. Agriculture (specifically wind erosion) was the largest source, with dust and fires (specifically dust from non-residential construction and unpaved roads) being the second-largest source of PM_2.5.

Ontario ranked third, with 19% (210 kt) of total national emissions, and Quebec ranked fourth with 13% (150 kt). For both provinces, dust and fires (specifically dust from unpaved roads) were the largest source of emissions.

The exclusion of emissions from dust and fires and agriculture (livestock, crop production and fertilizer) provides a different breakdown of PM_2.5 emissions in each province and territory. With these emissions removed, Quebec becomes the largest emitting province of PM_2.5 in 2024, representing 30% (46 kt) of total emissions (152 kt); home firewood burning was the largest emitting source (28 kt or 60%). Ontario ranks second with 24% (37 kt) of emissions. In this province, ore and mineral industries were the largest sources of emissions (10 kt or 26%) and home firewood burning was the second largest source (9 kt or 24%). Alberta and British Columbia rank third and fourth, representing 15% (23 kt) and 12% (18 kt) of emissions, respectively. In Alberta, the largest source of emissions was the oil and gas industry (9 kt or 39%), while in British Columbia it was the ore and mineral industries sector (5 kt or 31%). Between 1990 and 2024, with dust, fires and agriculture excluded, all provinces and territories experienced emission reductions, ranging from 81% in British Columbia (75 kt, primarily driven by reduction in manufacturing) to 23% in Northwest Territories and Nunavut (0.3 kt, primarily driven by reductions from the off-road vehicles and mobile equipment sector). 

Fine particulate matter emissions by facilities

The National Pollutant Release Inventory provides detailed information on air pollutant emissions from industrial and commercial facilities that meet its reporting criteria.

The Canadian Environmental Sustainability Indicators program provides access to this information through an interactive map. The map allows you to explore PM_2.5 emissions from individual facilities.

Key results

• In 2024, 4,634 facilities across Canada reported PM_2.5 emissions representing 4% of total national emissions. Of these facilities:
  • 2,484 facilities reported emissions under 1 tonne (t)
  • 2,063 facilities reported emissions between 1 to 100 t
  • 87 facilities reported emissions of 100 t or more, located in Quebec (21), British Columbia (18), Ontario (16), Alberta (11), Saskatchewan (10), Newfoundland and Labrador (5), New Brunswick (3), Manitoba (2), and Nunavut (1)

Fine particulate matter by reporting facilities, Canada, 2024

Navigate data using the interactive map

Source: Environment and Climate Change Canada (2026) National Pollutant Release Inventory.

Black carbon emissions by source

Black carbon is a component of PM_2.5 and is generated by the incomplete combustion of fossil fuels and biomass. It is a short-lived climate pollutant, contributing to climate warming and is linked to adverse human health effects. Reducing black carbon emissions can improve air quality, slow climate warming, reduce snow and ice melts, increase crop yields and reduce negative impacts to ecosystem health and human health.

Key results

• Emissions of black carbon were 18 kt in 2024, a decrease of 40% (12 kt) from 2013
• In 2024, 3 sectors accounted for 81% of national black carbon emissions:
  • off-road vehicles and mobile equipment
  • oil and gas industry
  • transportation (road, rail, air and marine) 

Total black carbon emissions by source, Canada, 2013 to 2024

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How this indicator was calculated

Note: The indicator reports air pollutant emissions from human activities only. It does not include emissions from natural sources such as forest fires. The chart includes emissions from the most significant sources of black carbon. “Other sources” includes emissions from ore and mineral industries, incineration and waste, manufacturing, electric utilities and agriculture. Consult Table 1 in the Data sources and methods for more details. The interactive figures provide a dynamic and customizable format to explore the emissions.
Source: Environment and Climate Change Canada (2026) Canada's Black Carbon Emissions Inventory.

In 2024, off-road vehicles and mobile equipment (for example, agricultural equipment, construction and mining equipment, commercial equipment, recreational vehicles and lawn and garden equipment) accounted for the largest proportion of total national emissions, representing 42% (8 kt) of emissions. Transportation (road, rail, air and marine) and the oil and gas industry were also large contributors, representing 24% (4 kt) and 15% (3 kt) of total national emissions, respectively. The remaining emissions came from home firewood burning, building heating and energy generation and other sources (such as the ore and mineral industries).

Black carbon emissions by province and territory

Key results

• In 2024, 4 provinces, Alberta, Saskatchewan, Ontario and Quebec, accounted for 74% (13 kt) of total national black carbon emissions
• Between 2013 and 2024:
  • all provinces and territories experienced reductions in black carbon emissions between 34% and 68%, with the largest reductions coming from the off-road vehicles and mobile equipment (44%, 6 kt) and transportation (road, rail, air and marine) (57%, 6 kt) sectors
  • Alberta, Ontario and Quebec experienced the largest reductions in emissions, with decreases of 2.8 kt, 2.4 kt and 2.2 kt, respectively. For these 3 provinces, the reductions were mainly attributable to lower emissions from transportation (road, rail, air and marine) and off-road vehicles and mobile equipment

Black carbon emissions by province and territory, Canada, 2013 and 2024

Air pollutant emissions from the oil and gas industry

The oil and gas sector is an important contributor to air pollutant emissions. Most emissions from the oil and gas sector come from upstream activities (including exploration, drilling, production and field processing) and to a lesser extent from downstream activities (including refining, storage and distribution). Air pollutants emitted by this sector contribute to the formation of fine particulate matter (PM_2.5), ozone (O₃), smog and acid rain. They also adversely affect human health, the environment and the economy.^{Footnote 13}

Key results

• In 2024, the oil and gas industry was a major contributor to total national emissions of sulphur oxides (SO_X) (42%), volatile organic compounds (VOCs) (40%), nitrogen oxides (NO_X) (37%) and carbon monoxide (CO) (12%)
• The oil and gas industry is also a source of emissions of fine particulate matter (PM_2.5) and ammonia (NH₃). However, in 2024, it made up only 1% of the respective total emissions of these pollutants

Contribution of the oil and gas industry to total air pollutant emissions by activity type, Canada, 2024

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Note: Fine particulate matter and ammonia are not shown in the chart due to their low share (2%) of total emissions in 2024. In the oil and gas industry, upstream activities include exploration, drilling, production and field processing and downstream activities include refining, storage and distribution.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory and Canada's Black Carbon Emissions Inventory.

In 2024, the oil and gas industry sector was the largest contributor to the total national emissions of SO_X, VOCs and NO_X. It was also the third-largest contributor to emissions of CO and black carbon.

Most emissions from the oil and gas industry came from upstream activities compared to downstream activities. In 2024, 97% of NH₃, 96% of VOC, NO_X and CO, 89% of PM_2.5, 84% of SO_X and almost 100% of black carbon emissions from the oil and gas sector were from upstream activities.

Changes in emissions from the oil and gas industry

Key results

• Between 1990 and 2024:
  • SO_X and VOC emissions decreased 57% and 10%, respectively
  • CO and NO_X emissions increased by 58% and 30%, respectively
• Black carbon emissions increased by 3% between 2013 and 2024

Changes in emissions of key air pollutants from the oil and gas industry, Canada, 1990 to 2024 and 2013 to 2024

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Note: Fine particulate matter and ammonia are not shown in the chart due to their low share (2%) of total emissions in 2024. Black carbon emissions reporting did not begin until 2013, marking the fist year of the Black Carbon Emissions Inventory.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory and Canada's Black Carbon Emissions Inventory.

The increases in CO and NO_X emissions between 1990 and 2024 were due to growth in oil and gas production (the upstream sector of the industry), as emissions from the downstream sector declined due to facility closures during that period.^{Footnote 14} This increase is in part explained by the fact that crude oil production in Canada more than doubled since 1990. The growth was mostly driven by a rapid increase in oil sands production, particularly by in-situ oil sands extraction. During the same period, production of natural gas from unconventional sources, such as those requiring the use of multi-stage fracturing techniques, also increased significantly.

Black carbon emissions have remained somewhat stable between 2013 and 2024.

The decrease in SO_X emissions was mainly due to reductions in emissions from oil sands mining, extraction and upgrading, and natural gas production and processing, attributed to better emission control technologies.

For VOCs, the recent decline was partly due to reductions in heavy crude oil production and petroleum refining, storage and distribution. The decrease in VOC emissions was also driven by reduced venting emissions from crude oil production since 2014. During this period, operators took measures to conserve gas under provincial directives, even prior to the implementation of federal and provincial regulations. In addition, federal and provincial regulations to reduce fugitive emissions from the sector came into effect in 2020, further contributing to the decline.

Air pollutant emissions from transportation, off-road vehicles and mobile equipment

Transportation, off-road vehicles and mobile equipment are among the largest sources of air pollutants in Canada. Burning fossil fuels to power vehicles and engines causes emissions of many air pollutants. Some of these air pollutants lead to the formation of fine particulate matter, ozone, smog and acid rain. These pollutants and resulting impacts adversely affect human health, the environment and the economy.

Key results

• In 2024, transportation, off-road vehicles and mobile equipment accounted for more than half (60%) of total national emissions of carbon monoxide (CO), 38% of nitrogen oxides (NO_X), 24% of black carbon and 13% of total emissions of volatile organic compounds (VOCs)
• While also a source of emissions for fine particulate matter (PM_2.5), ammonia (NH₃) and sulphur oxides (SOx), the sector represented less than 2% of those emissions in 2024, respectively

Contribution of transportation, off-road vehicles and mobile equipment to total air pollutant emissions by transportation mode, Canada, 2024

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Note: Sulphur oxides are not shown in the chart due to their low share (≤ 1%) of total emissions in 2024. "Passenger cars and motorcycles" include cars powered by motor gasoline, diesel, liquefied petroleum gas and compressed natural gas engines as well as all types of motorcycles. "Passenger light trucks" include light-duty trucks powered by motor gasoline, diesel, liquefied petroleum gas and compressed natural gas engines. "Large trucks and buses" include heavy-duty trucks powered by motor gasoline, diesel, liquefied petroleum gas and compressed natural gas engines.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory and Canada's Black Carbon Emissions Inventory.

The contribution of each transportation mode to emissions of different air pollutants is in large part explained by the mix of fuels used in these modes.

Large trucks and buses and rail and marine travel rely predominantly on diesel fuel, which emits significantly more PM_2.5 (most of which is black carbon) and NO_X than gasoline per kilometre traveled. Aviation relies on turbo aviation fuel. These transportation modes are the largest sources of NO_X transportation-related emissions accounting for 22% (267 kilotonnes [kt]) of total NO_X emissions. These sources may be particularly important near transportation hubs (for example airports, major docks, etc.), where they can contribute to localized air pollution.

Passenger cars and light trucks mostly use gasoline and are an important source of multiple pollutants, especially in urban centres. In 2024, emissions from passenger cars, motorcycles and light trucks amounted to 844 kt of CO, 35 kt of NO_X and 49 kt of VOCs. These emissions represented 19%, 3% and 4% of the national total emissions of these pollutants, respectively.

Off-road vehicles and equipment^{Footnote 15} are also a significant source of pollution. Their combined emissions make up 36%, 13% and 9% of the total emissions of CO, NO_X and VOCs, respectively. Emissions mostly come from household use of gasoline- or diesel-powered recreational and lawn and garden equipment, and from the operation of agricultural, construction and mining equipment (commercial use). In 2024, commercial equipment use produced higher emissions of NOx, SOx, NH₃ and CO compared to lawn and garden equipment use. However, emissions of PM_2.5 and VOCs were greater from recreational and lawn and garden equipment use than from commercial equipment use.

Changes in emissions from transportation, off-road vehicles and mobile equipment

Key results

• Between 1990 and 2024, total emissions of NO_X, VOCs and CO from transportation, off-road vehicles and mobile equipment decreased by 63%, 71% and 73%, respectively
  • Since 2000, all 3 pollutants demonstrated the same downward trend in their emissions levels
• Between 2013 and 2024, total black carbon emissions from transportation, off-road vehicles and mobile equipment decreased by 57%

Changes in emissions of key air pollutants from transportation, off-road vehicles and mobile equipment, Canada, 1990 to 2024 and 2013 to 2024

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How this indicator was calculated

Note: Fine particulate matter, sulphur oxides and ammonia are not shown in the chart due to their low share (≤ 4%) of total emissions in 2024. Black carbon emissions reporting did not begin until 2013, marking the fist year of the Black Carbon Emissions Inventory.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory and Canada's Black Carbon Emissions Inventory.

Pollutant emissions have decreased despite economic and population growth as well as increased transportation activities for the period between 1990 and 2024. This decrease is mainly attributable to the adoption of new regulations that led to the gradual introduction of emission control technologies and clean fuel for vehicles.

Between 1990 and 2000, NO_X emissions increased by 23% (293 kt). This includes the increase in emissions from light trucks (130 kt or 116%), large trucks and buses (70 kt or 18%), marine transportation (10 kt or 17%) and air transportation (1 kt or 19%), which can be linked to economic and population growth during that time. From 2000 to 2024, new regulations contributed to a decrease in NO_X emissions (617 kt or 68%) from light trucks (91% or 220 kt), large trucks and buses (73% or 327 kt) and emissions from rail travel (50% or 70 kt).

Transportation emissions are influenced by a variety of factors. These include population and economic growth, volume of passenger and freight travel, vehicle type, emission control technologies, transportation infrastructure, fuel efficiency and fuel type.

Air pollutant emissions from the electric utilities

Electricity generation produces sulphur oxides (SO_X) and nitrogen oxides (NO_X). SO_X and NO_X are mostly emitted from power plants burning fossil fuels such as coal and, to a lesser extent, natural gas and diesel. These air pollutants contribute to the formation of fine particulate matter, ozone, smog and acid rain. They also adversely affect human health, the environment, and the economy.

Key results

• In 2024, electric utilities were the source of 20% and 7% of total national emissions of SO_X and NO_X, respectively
  • Most of the air pollutant emissions from electric utilities come from burning coal
• Electric utilities are also a source of carbon monoxide (CO), volatile organic compounds (VOCs), fine particulate matter (PM_2.5) and ammonia (NH₃) emissions. However, they account for less than 1% of the total national emissions of these pollutants

Contribution of electric utilities to total air pollutant emissions by fuel source, Canada, 2024

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Note: Carbon monoxide, fine particulate matter, volatile organic compounds, ammonia and black carbon are not shown in the chart due to their low share (1%) of total emissions in 2024. The indicator excludes emissions from industries that generate electricity and heat as a supporting activity rather than as their primary purpose. "Other sources" include fuel sources such as waste material and other uncategorized sources of electricity generation.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

In 2024, 95% of SO_X and 45% of NO_X emissions from electric utilities came from burning coal.

A large share of the electricity generated in Canada comes from sources that do not directly emit air pollutants:

• 62% of electricity comes from hydroelectric power generation
• 13% comes from nuclear power plants
• 8% comes from non-hydroelectric renewable sources, such as wind, solar, tidal power and biomass^{Footnote 16}

Changes in emissions from electric utilities

Key results

• Between 1990 and 2024
  • emissions of SO_X and NO_X from electric utilities declined by 82% and 68%, respectively
  • most of the decrease in emissions occurred from 2005 onward

Changes in emissions of key air pollutants from electric utilities, Canada, 1990 to 2024

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How this indicator was calculated

Note: Carbon monoxide, fine particulate matter, volatile organic compounds, ammonia and black carbon are not shown in the chart due to their low share (1%) of total emissions in 2024. Excludes emissions from industries that generate electricity and heat as a supporting activity rather than as their primary purpose.
Source: Environment and Climate Change Canada (2026) Air Pollutant Emissions Inventory.

The majority of the reductions in SO_X and NO_X emissions between 1990 and 2024 occurred from 2005 onwards. Between 2005 and 2024, the percentage of electricity from burning fossil fuels fell from 25% to 19%. The decrease in emissions since 2005 are mainly due to reductions in the use of coal power plants for electricity generation^{Footnote 17} as a result of:

• the change in the mix of energy sources used to generate electricity
• the introduction of regulations targeting air pollutants and greenhouse gases emitted from electricity generation facilities
• domestic and international agreements
• better pollutant removal technologies used in smokestacks
• power plant closures

The Air Pollutant Emissions Inventory and the Black Carbon Emissions Inventory provide data and estimates on releases of air pollutants from human activities. These pollutants contribute to smog, acid rain, reduced air quality and climate change. Improvements to data and the methods for trend analysis are made periodically as new emission estimation methodologies are adopted and additional information is made available. Historical emissions are updated based on these improvements.

Air Pollutant Emissions Inventory

The Air Pollutant Emissions Inventory fulfills many of Canada's international obligations for reporting on pollution levels. Specifically, under the 1979 Convention on Long-range Transboundary Air Pollution, Canada has committed to submitting an annual inventory of emissions of key air pollutants to the United Nations Economic Commission for Europe. The inventory is a comprehensive assessment of 17 air pollutants,^{Footnote 22} combining emissions reported by facilities to the National Pollutant Release Inventory with emissions of all other sources estimated by Environment and Climate Change Canada. Estimates are developed using the latest estimation methods and are based on published statistics or other sources of information such as surveys and reports. The Air Pollutant Emission Inventory provides a comprehensive overview of pollutant emissions across Canada.

The national and provincial/territorial inventory data are current as of March 13, 2026 and cover the period from 1990 to 2024. Emissions data are compiled into a database for reporting approximately 1 year after data collection, validation and calculation have been completed. After this process is the interpretation of results and public reporting of the inventory. The Air pollutant emissions indicators are published following the public release of the inventory data.

Black carbon emissions inventory

As a member of the Arctic Council, Canada committed under the Framework for Action on Enhanced Black Carbon and Methane Emissions Reductions (2015) to submit periodic inventories of its black carbon emissions to the Arctic Council Secretariat. Canada also voluntarily reports black carbon emissions to the United Nations Economic Commission for Europe as a Party to the Gothenburg Protocol, which was amended in 2012 to add fine particulate matter (including black carbon). The Black Carbon Emissions Inventory is compiled using PM_2.5 emissions data from combustion-related sources from the Air Pollutant Emissions Inventory. Black carbon estimates are published separately from the Air Pollutant Emissions Inventory. The data are current as of March 13, 2026.

Black carbon is a short-lived climate pollutant (SLCP), meaning it contributes to warming but has a relatively short lifespan in the atmosphere (from a few days to a few weeks) This lifespan is short compared to carbon dioxide (CO₂), which can persist in the atmosphere for hundreds to thousands of years, and compared to other longer-lived greenhouse gases (GHGs). Although their life spans are short, SLCPs are potent contributors to warming of the Earth's surface.^{Footnote 23}  When black carbon deposits on snow and ice, it darkens the surface, accelerating heating and melting, creating a warming impact that is particularly strong in the Arctic and other snow covered areas (including glaciers).^{Footnote 24} Reducing emissions of SLCPs, including black carbon, can help slow near-term warming – the impacts of reductions are seen quickly because SLCPs have such short lifespans in the atmosphere. The Intergovernmental Panel on Climate Change (IPCC) special report on Global Warming states that reductions in short-lived climate pollutants are required to limit warming to a maximum of 1.5ºC. Also, Canada's Changing Climate Report flags short-lived climate pollutants as an important part of climate policy discussions because mitigation can slow global temperature warming and improve air quality.

National Pollutant Release Inventory

The National Pollutant Release Inventory is a database of pollutant releases (to air, water and land), disposals and transfers for recycling from industrial, commercial and institutional facilities. The data from these facilities is provided by the operators of the facilities as mandated by the Canadian Environmental Protection Act (the Act). Under the Act, owners or operators of facilities that manufacture, process or otherwise use or release one or more of the substances tracked by the inventory, and meet substance-specific reporting thresholds and other requirements, must report their pollutant releases, disposals and transfers annually to the department. The inventory data from 1993 to 2024 are current as of May 19, 2026.

Compilation of air pollutant emissions

The Air Pollutant Emissions Inventory is developed using 2 types of information:

• facility-reported data, consisting of emissions from relatively large industrial, commercial and institutional facilities
• in-house estimates, including diffuse sources and other sources that are too numerous to be accounted for individually, such as road and non-road vehicles, agricultural activities, construction and solvent use

The Air Pollutant Emissions Inventory is developed using many sources of information, procedures and emission estimation models. Emissions data reported by individual facilities to the department's National Pollutant Release Inventory are supplemented with documented, science-based estimation tools to quantify total emissions. Together, these data sources provide a comprehensive overview of pollutant emissions across Canada.

A compilation framework has been developed that makes use of the best available data, while ensuring that there are no double-counting or omissions. Additional information on the inventory compilation process is provided in Chapter 3 of the Air Pollutant Emissions Inventory Report.

Facility-reported emissions data

Facility-reported emissions data generally refers to any stationary sources that emit pollutants through stacks or other equipment at specific locations. The major source of facility-reported data is the National Pollutant Release Inventory.

Facility-reported data from the National Pollutant Release Inventory are used in the Air Pollutant Emissions Inventory without modifications, except when data quality issues are detected and not addressed during the quality control exercise. The National Pollutant Release Inventory reporting requirements and thresholds vary by pollutant and, in some cases, by industry. Details on these reporting requirements and thresholds are available on the National Pollutant Release Inventory website.

A distinction has been made between reporting facilities and non-reporting facilities. Reporting facilities meet the threshold required to report to the National Pollutant Release Inventory while non-reporting facilities do not meet these thresholds due to their size or emission levels and therefore are not required to report to the inventory. Some facilities may be required to report emissions of only certain pollutants. Therefore, emissions from the non-reporting facilities or of non-reported pollutants must be estimated in‑house to ensure complete coverage of most sources.

In-house emission estimates

In-house emission estimates are calculated with information such as production data and activity data, using various estimation methodologies and emission models. These emission estimates are at the national provincial and territorial levels, rather than at any specific geographic locations. These include emissions from non-industrial, residential, commercial, transportation, and other sources, such as open burning, agricultural activities and construction operations. The Air Pollutant Emissions Inventory uses in-house estimates for the following emission sources:

• any residential, governmental, institutional, or commercial operation that does not report to the National Pollutant Release Inventory
• on-site solid waste disposal facilities
• motor vehicles, aircraft, vessels or other transportation equipment or devices
• other sources, such as open burning, agricultural activities and construction operations

In general, in-house emission estimates are calculated from activity data and emission factors.^{Footnote 25} Activity data usually comprise statistical production or process data at the provincial, territorial or national level. This information is typically provided by provincial/territorial agencies, federal government departments, industry associations, etc. For each source category, activity data are combined with emission factors to produce provincial/territorial-level emission estimates.

The in-house emission estimate methodologies and emission models used in Canada are often based on those developed by the United States Environmental Protection Agency (U.S. EPA) and are adapted to reflect the Canadian climate, fuels, technologies and practices. Methods used in Canada's Air Pollutant Emissions Inventory are therefore generally consistent with those used in the United States or those recommended in the emission inventory guidebook.^{Footnote 26} 

The Air Pollutant Emissions Inventory reports air pollutant emissions from mobile sources such as on-road vehicles, off-road vehicles and engines. For the current edition of the Air Pollutant Emissions Inventory, an emissions estimation model developed by the U.S. EPA (MOVES) was used. The emissions for off-road vehicles and engines (such as graders, heavy trucks, outboard motors and lawnmowers) were estimated using the U.S. EPA's NONROAD emission estimation model (see "off-road vehicles and equipment" in Table A2-1 of Annex 2 of the Air Pollutant Emissions Inventory Report). The parameters in both models were modified to take into account variations in the Canadian vehicle fleet, emission control technologies, types of fuels, vehicle standards, and types of equipment engines and their application in various industries. The emission estimates for civil and international aviation, railways and navigation are estimated using detailed vehicle movement statistics coupled with fuel consumption, engine information, and emission rates by vehicle types.

Calculation of black carbon emissions

Emissions of black carbon are calculated by applying factors to estimate the fraction of black carbon in PM_2.5 emissions from combustion-related sources, with some exceptions, for example, the mobile sources, where models are used. The factors primarily come from the United States Environmental Protection Agency's SPECIATE database. SPECIATE is a repository of particulate matter speciation profiles^{Footnote 27}  of air pollution sources. The ratios used for each source are available on the Government of Canada’s Open Data Portal. More information on black carbon emission estimation methods can be found in Chapter 3 of Canada’s Black Carbon Inventory Report.

Recalculations

Emission recalculation is an essential practice in the maintenance of an up-to-date air pollutant emissions inventory. The Air Pollutant Emissions Inventory is continuously updated with improved estimation methodologies, statistics and more recent and appropriate emission factors. As new information and data become available, previous estimates are updated and recalculated to ensure a consistent and comparable trend in emissions. Recalculations of previously reported emission estimates are common for both in-house estimates and facility-reported emission data. More information on recalculations is provided in Annex 3 of the Air Pollutant Emissions Inventory Report.

Emissions reconciliation

In several sectors, estimation of total emissions involves combining estimates provided by facilities with estimates developed in-house by the department. To prevent double counting of emissions and to confirm that the Air Pollutant Emissions Inventory includes all emissions, a comparison and reconciliation of emission estimates from various sources is performed for each pollutant, industry sector and geographical region, as appropriate. More information on the reconciliation process is provided in section 3.4 of the Air Pollutant Emissions Inventory Report.

Temporal coverage

Historical data are provided at the national level for the period from 1990 to 2024, except for black carbon, which covers the period from 2013 to 2024. For the regional indicators (provincial/territorial), emissions are presented for 1990 (2013 for black carbon) and 2024. Facility level emissions information are available from 2012 to 2024.

Air pollutant emissions by source classification

For the purpose of reporting the indicators, calculated emissions data from the Air Pollutant Emissions Inventory and Black Carbon Emissions Inventory are grouped into the following 13 sources:

1. agriculture (livestock, crop production and fertilizer)
2. building heating and energy generation
3. dust and fires
4. electric utilities
5. home firewood burning
6. incineration and waste
7. manufacturing
8. miscellaneous
9. off-road vehicles and mobile equipment
10. oil and gas industry
11. ore and mineral industries
12. paints and solvents
13. transportation (road, rail, air and marine)

Table 1 shows the allocation of air pollutant emission sources reported in the indicators compared with the sources and sectors reported by the Air Pollutant Emissions Inventory.

Note: ^[A] Includes electric power generation from combustion of waste materials by utilities and by industry for commercial sale and/or private use. ^[B] Includes human respiration, perspiration and dental amalgams.

For display purposes, smaller emitting sources are sometimes grouped together under the title Other sources in the charts of air pollutant emissions by source. The names of the sources grouped as such are listed in the notes of each chart.

Sectoral indicators

For display purposes, smaller emitting sources are sometimes grouped together under the title “Other sources” in the charts of air pollutant emissions by source. The names of the sources grouped as such are listed in the notes of each chart.

Sectoral indicators

Sectoral indicators provide additional analysis on air pollutant emissions from transportation, off-road vehicles and mobile equipment, electric utilities and the oil and gas industry. These indicators rely on calculated emissions data from the Air Pollutant Emissions Inventory and the Black Carbon Emissions Inventory.

These indicators are provided at the national level. They identify the contribution of each sector to the national emissions of air pollutants for the year 2024. They also provide information about emissions of selected pollutants, by sector, for the period from 1990 to 2024.

Tables 2 through 4 below show the alignment of air pollutant emission sources reported in the Air pollutant emissions indicators compared with those reported by the sectoral indicators.

Note: ^[A] Includes electric power generation from combustion of waste materials by utilities and by industry for commercial sale and/or private use.