Canada’s Air Pollutant Emissions Inventory Report: chapter 1


1.1  Background on the Air Pollutant Emissions Inventory

Canada’s Air Pollutant Emissions Inventory (APEI) is a comprehensive inventory of air pollutant emissions at the national and provincial/territorial levels. The APEI is prepared and published by Environment and Climate Change Canada (ECCC) and serves many purposes, including the following:

  • contribute to tracking and quantifying air pollutants in accordance with Canada’s domestic and international reporting obligations
  • support to the development of domestic air quality management strategies, policies and regulations
  • inform Canadians about pollutants that affect their health and the environment
  • provide data to support air quality forecasting

The first national inventory of air pollutant emissions in Canada was compiled in 1973, with national and provincial/territorial estimates of emissions of carbon monoxide (CO), sulphur oxides (SOx), nitrogen oxides (NOx), hydrocarbons and particulate matter (PM) for the year 1970. Since then, air emission estimates for Canada have continued to be published on a regular basis.

Today the APEI includes emissions data for 17 air pollutants that contribute to smog, acid rain and diminished air quality, including:

  • smog precursors: total particulate matter (TPM), PM less than or equal to 10 microns (PM10), PM less than or equal to 2.5 microns (PM2.5), SOx, NOx, volatile organic compounds (VOCs), CO and ammonia (NH3)
  • heavy metals: mercury (Hg), lead (Pb) and cadmium (Cd)
  • persistent organic pollutants (POPs): dioxins and furans (D/F), four polycyclic aromatic hydrocarbon (PAH) compounds (benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[1,2,3-cd]pyrene), and hexachlorobenzene (HCB)

The reporting format for the APEI organizes emissions into 11 source categories that are further broken down into 74 sectors and 72 associated subsectors (Table 1-1). The APEI is compiled and published on an annual basis. The time series of annual emissions contained in this report is updated across the times series, from 1990 to the most recent inventory year, to indicate the trend in emissions are based on consistent and current methodological approaches and data.

Facility emissions data captured in the APEI originate primarily from the National Pollutant Release Inventory (NPRI), supplemented with data provided by provincial governments (Alberta, Manitoba, New Brunswick, Newfoundland and Labrador, Ontario and Quebec). For example, Alberta provides additional data for the Upstream Petroleum sector for the pre-2006 years, and Alberta and Newfoundland provide supplementary information for selected sources that are not reported to the NPRI. In addition to supplementing the NPRI data with additional data sources as described above, the APEI incorporates estimated emissions for sources not reported to the NPRI, for example when an APEI sector includes facilities that are below the NPRI reporting threshold.

Table 1-1 Air Pollutant Emissions Inventory sector descriptions

Ore and Mineral Industries
APEI sector Sector descriptions
Aluminium Industry Alumina production through bauxite refining, primary aluminium production through smelting and refining and secondary aluminium production in which aluminium is recovered from aluminium-containing scrap.
Asphalt Paving Industry Asphalt concrete (or hot-mix asphalt) manufacturing. Emissions are from permanent and portable hot-mix asphalt installations.
Cement and Concrete Industry Entire process of cement production in rotary kilns, as well as the preparation of concrete and ready-mix concrete, lime manufacture and concrete batching and products.
Foundries Castings of various types of ferro-alloys as well as small iron and steel foundries not associated with integrated iron and steel facilities. The types of foundries included are: open ferrous, electric arc and induction foundries.
Iron and Steel Industry Steel production, including blast furnaces, basic oxygen furnaces, electric arc furnaces, sintering, direct reduction of iron, hot forming and semi-finishing, coke production.
Iron Ore Industry Iron ore mining, beneficiation by concentration and sintering into pellets are included.
Mineral Products Industry Manufacture of brick, clay products such as pipes, liner and tiles and other mineral products such as gypsum and glass products.
Mining and Rock Quarrying Overburden removal, drilling in rock, blasting, crushing of rock, loading of materials, transporting raw materials by conveyors or haulage trucks, scraping, bulldozing, grading, open storage pile losses and wind erosion from exposed areas.
Non-Ferrous Refining and Smelting Industry Primary copper and nickel production using pyrometallurgical operations, lead ore crushing, concentrating and metallurgic processing and zinc metal production through electrolytic processes.
Oil and Gas Industry
APEI sector Sector descriptions
Downstream Oil and Gas Industry Refining and processing of crude oil to make fuels or other products such as solvents or asphalt. Storage and distribution of refined petroleum products, natural gas distribution and liquid natural gas (LNG) processing.
Upstream Oil and Gas Industry Drilling, testing and servicing of wells, conventional oil and gas production, in situ bitumen extraction and open pit mining, oil sands upgrading, natural gas processing, crude oil transmission, natural gas transmission and storage.
Electric Power Generation (Utilities)
APEI sector Sector descriptions
Coal Electric power generation from combustion of coal by utilities (both publicly and privately owned) for commercial sale and/or private use.
Diesel Electric power generation from combustion of diesel by utilities (both publicly and privately owned) for commercial sale and/or private use.
Natural Gas Electric power generation from combustion of natural gas by utilities (both publicly and privately owned) for commercial sale and/or private use.
Waste Materials Electric power generation from combustion of waste materials by utilities (both publicly and privately) for commercial sale and/or private use.
Other (Electric Power Generation) Electric power generation from other energy sources by utilities (both publicly and privately owned) for commercial sale and/or private use.
APEI sector Sector descriptions

Abrasives Manufacture

Manufacturing of abrasive grinding wheels, abrasive-coated materials and other abrasive products.


Manufacturing of bakery products, including frozen baked products.

Biofuel Production

Production of ethanol for fuel or oils for biodiesel.

Chemicals Industry

Large number of different product industries including fertilizer manufacturing, plastic resins, paints and varnishes, petrochemicals, inorganic chemicals, and pharmaceuticals. The raw materials, processes used and products produced are in many cases unique to individual plants.


Manufacturing of electronics, such as communications equipment, semiconductors and electronic components, navigational and guidance instruments, electric lamp bulb and parts, transformers, switchgear, relay and industrial control.

Food Preparation

Activities related to food production for human or animal consumption, such as manufacturing of dog and cat food, sugar and confectionery products, frozen food, dairy products, meat products, and beverage products; seafood product preparation and packaging; and fruit and vegetable canning, pickling and drying; snack, dressing, and tobacco products.

Glass Manufacturing

Making of glass from sand and cullet as well as the remelting, pressing, blowing or otherwise shaping purchased glass.

Grain Industry

Primary, process, terminal and transfer elevators, as well as manufacturing or processing grain for use in other products.

Metal Fabrication

Activities related to metal fabrication, such as: iron and steel mills and ferro-alloy manufacturing; production of iron and steel pipes and tubes, cold-rolling steel bars, sheets, strips and other steel shapes; steel wire drawing; smelting of non-ferrous metals; copper rolling, drawing, extruding and alloying; forging; stamping; and other metal manufacturing.

Plastics Manufacturing

Manufacturing of plastics bags, plastic film and sheet, unlaminated plastic profile shapes, plastic pipes and pipe fittings, laminating plastic profile shapes (plates, sheets and rods), polystyrene foam products, urethane, and other foam products.

Pulp and paper Industry

Chemical, mechanical, recycling and semi-chemical mills, including the production of energy through the combustion of spent pulping liquor, biomass and fossil-fuel combustion. Also includes fugitive emissions from wood refining, screening and drying, and various steps in chemical recovery systems.


Textile product-related activities, including: fibre, yarn and thread manufacturing; textile and fabric finishing; fabric coating; carpet and rug manufacturing; clothing knitting; as well as clothing accessories and other clothing manufacturing.

Vehicle Manufacturing (Engines, Parts, Assembly, Painting)

Activities related to: vehicle manufacturing, such as manufacturing of motor vehicles plastic parts, engine and power transmission equipment, automobile and light-duty motor vehicles, heavy-duty trucks, truck trailers, motor vehicle brake systems, seating and interior trim, and vehicle parts; urban transit systems; and support activities for rail transportation.

Wood Products

Sawmills, panelboard mills (including veneer, plywood, waferboard, particle board and medium-density fiberboard mills), and other wood products manufacturing establishments (including furniture and cabinet makers, wood treating plants, wood pellet mills and Masonite manufacturers).

Other (Manufacturing)

Manufacturing and processing industries that are not included under a specific industrial sector, such as asphalt shingle and coating activities, rubber manufacturing, and ship building and repair.

Transportation and Mobile Equipment
APEI sector Sector descriptions
Air transportation Piston and turbine aircraft used for military, commercial and private operations.
Heavy-duty diesel vehicles Diesel vehicles over 3 856 kilograms.
Heavy-duty gasoline vehicles Gasoline vehicles over 3 856 kilograms.
Heavy-duty LPG/NG vehicles Propane and natural gas vehicles over 3 856 kilograms.
Light-duty diesel trucks Diesel trucks under 3 856 kilograms.
Light-duty diesel vehicles Diesel vehicles under 3 856 kilograms.
Light-duty gasoline trucks Gasoline trucks under 3 856 kilograms.
Light-duty gasoline vehicles Gasoline vehicles under 3 856 kilograms.
Light-duty LPG/NG trucks Propane and natural gas trucks under 3 856 kilograms.
Light-duty LPG/NG vehicles Propane and natural gas vehicles under 3 856 kilograms.
Marine transportation Marine craft in anchored, berth and underway phases.
Motorcycles Motorcycles.
Off-road diesel vehicles and equipment Off-road vehicles and mobile equipment using diesel fuel in mining, construction, agriculture, commercial purposes, logging, railway maintenance, and airport ground support; lawn and garden equipment using diesel fuel; and recreational vehicles using diesel fuel.
Off-road gasoline/LPG/CNG vehicles and equipment Off-road vehicles and mobile equipment using gasoline, liquid petroleum gas, and compressed natural gas in mining, construction, agriculture, commercial purposes, logging, railway maintenance, airport ground support; lawn and garden equipment using gasoline, liquid petroleum gas, or compressed natural gas; and recreational vehicles using gasoline, liquid petroleum gas, and compressed natural gas.
Rail transportation Freight and passenger trains, including yard switching activities.
Tire wear and brake lining Tire and brake lining wear from all categories of road transportation.
APEI sector Sector descriptions
Animal Production Decomposition of animal feed, animal digestion, and manure in housing, storage, applied to agricultural soils, or deposited during grazing.
Crop Production Application of synthetic nitrogen fertilizers, tillage, wind erosion and crop harvesting.
Fuel Use Stationary combustion sources in agricultural facilities such as space and water heating and crop drying.
Commercial / Residential / Institutional
APEI sector Sector descriptions
Cigarette Smoking Mainstream cigarette smoke, which is directly exhaled by the smoker and sidestream smoke, which is directly released from burning cigarettes.
Commercial and Institutional Fuel Combustion Combustion of fossil and biogenic fuels used for space/water heating in commercial establishments, health and educational institutions and government/public administration facilities.
Commercial Cooking Cooking meat and french fries in commercial foodservice operations.
Construction Fuel Combustion Combustion of fossil fuels used for space heating and the heating of construction materials, such as concrete.
Home Firewood Burning Burning of wood and pellets as fuel for space heating and hot water. Includes emissions from fireplaces, wood stoves and wood-fired boilers.
Human Human respiration, perspiration, dental amalgams and infant diapered waste.
Marine Cargo Handling Handling, loading and unloading of materials, goods and merchandise between ships and docks.
Residential Fuel Combustion Combustion of fossil fuels used for space/water heating in residences.
Service Stations Fuel transfers and storage at service stations, as well as individuals refueling vehicles and off-road equipment.
Other (Commercial / Residential / Institutional) Hg in products and facility-reported data from sectors that are not included elsewhere.
Incineration and Waste
APEI sector Sector descriptions
Crematoriums Combustion of caskets and human bodies, as well as companion animals.
Waste Incineration Incinerators used to combust municipal, commercial and industrial waste including sewage sludge as well as residential waste burning.
Waste Treatment and Diposal Landfilling of waste, biological treatment of waste, specialized waste treatment and remediation, waste sorting and transfer as well as municipal wastewater treatment and discharge (including drinking water treatment).
Paints and Solvents
APEI sector Sector descriptions
Dry Cleaning Dry cleaning of fabric and leather items.
General Solvent Use Broad range of applications occurring in residential, commercial, industrial and institutional locations. Industrial applications include uses such as: degreasing, adhesives and sealants, aerosols, blowing agents, and resin manufacturing. The use of consumer and commercial products, pesticides and personal care products are also included.
Printing Manufacturing or use of printing inks, which includes: flexographic, gravure, letterpress, lithographic and other printing.
Surface Coatings Broad range of applications and industries, including individuals and companies engaged in the manufacturing or use of paints and coatings.
APEI sector Sector descriptions
Coal Transportation Transportation of coal by train or truck.
Construction Operations Soil disturbance on construction sites (residential, industrial-commercial-institutional [ICI], engineering).
Mine Tailings Wind erosion at mine tailings ponds located on active and inactive mine sites.
Paved Roads Re-suspension of particulate matter by vehicles travelling on paved roads.
Unpaved Roads Re-suspension of particulate matter by vehicles travelling on unpaved roads.
APEI sector Sector descriptions
Prescribed Burning Controlled fires used for land management treatments such as reducing logging residues, managing forest production, controlling insects, and minimizing the potential for destructive wildfires. Excludes the burning of agricultural residues.
Structural Fires Vehicle fires (including trains and airplanes) and fires that burn buildings.

1.2 Reporting requirements

The Convention on Long-range Transboundary Air Pollution (CLRTAP) endeavours to limit and, as far as possible, gradually reduce and prevent air pollution. Since 1979 when it was originally signed, the Convention has been extended by eight protocols, seven of which identify measures to be taken by Parties to achieve the Convention’s objectives; the eighth protocol concerns financing. Canada has ratified six of the protocols under the Convention that have come into force including:

  • the 1985 Helsinki Protocol on the Reduction of Sulphur Emissions (SOx)
  • the 1994 Oslo Protocol on Further Reduction of Sulphur Emissions (SOx for a designated “Sulphur Oxides Management Area” [SOMA])
  • the 1988 Sofia Protocol concerning the Control of Emissions of Nitrogen Oxides (NOx)
  • the 1998 Aarhus Protocol on Heavy Metals (Cd, Pb and Hg)
  • the 1998 Aarhus Protocol on Persistent Organic Pollutants (including D/F, four species of PAHs, and HCB, among other POPs); and
  • the 1999 Protocol to Abate Acidification, Eutrophication and Ground-level Ozone and its 2012 amended version

These protocols set specific emissions reduction targets for sulphur, NOx, Cd, Pb, Hg, dioxins and furans, PAHs, and HCB. Parties are required to report emissions to the United Nations Economic Commission for Europe (UNECE) each year by February 15.

In addition, Canada collects and publishes data on emissions of NH3, CO and three categories of PM (TPM, PM10 and PM2.5) and voluntarily reports the emissions of these five substances, along with the twelve substances for which there are protocols, to the UNECE annually. Canada has ratified the 1984 Geneva Protocol on Long-term Financing of the Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe.

Canada and the United States work jointly to address shared concerns regarding transboundary air pollution. Under the Canada–U.S. Air Quality Agreement, Canada monitors and reports emissions of SO2, NOx and VOCs other than methane.

1.3 Environmental measures and regulations for air pollutants

Downward trends in emissions of air pollutants reflect the ongoing implementation of a wide range of regulatory and non-regulatory instruments that aim to reduce or eliminate pollutants in order to improve and maintain air quality in Canada. Regulations under the Canadian Environmental Protection Act, 1999 (CEPA) related to the 17 APEI pollutants include, but are not limited to the following:

  • Multi-Sector Air Pollutants Regulations
  • Volatile Organic Compound (VOC) Concentration Limits for Automotive Refinishing Products Regulations
  • Volatile Organic Compound (VOC) Concentration Limits for Architectural Coatings Regulations
  • Marine Spark-Ignition Engine, Vessel and Off-Road Recreational Vehicle Emission Regulations
  • Off-Road Compression-Ignition Engine Emission Regulations
  • Off-Road Small Spark-Ignition Engine Emission Regulations
  • On-Road Vehicle and Engine Emission Regulations
  • Benzene in Gasoline Regulations
  • Contaminated Fuel Regulations
  • Gasoline and Gasoline Blend Dispensing Flow Rate Regulations
  • Gasoline Regulations
  • Renewable Fuels Regulations
  • Sulphur in Diesel Fuel Regulations
  • Sulphur in Gasoline Regulations
  • Products Containing Mercury Regulations
  • Secondary Lead Smelter Release Regulations
  • Export of Substances on the Export Control List Regulations
  • Pulp and Paper Mill Effluent Chlorinated Dioxins and Furans Regulations

All regulations administered under CEPA are available on the CEPA Environmental Registry.

Non-regulatory instruments include guidelines for new stationary combustion turbines, codes of practice, and performance agreements. Pollution prevention planning notices were published to reduce air pollutant emissions from the aluminium, iron, steel and ilmenite, iron ore pellets, potash, pulp and paper, and base-metals smelting sectors.

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