Canada’s Air Pollutant Emissions Inventory Report: executive summary

Canada’s Air Pollutant Emissions Inventory (APEI) has been prepared and published by Environment and Climate Change Canada since 1973. The APEI is a comprehensive inventory of anthropogenic emissions of 17 air pollutants at the national and provincial/territorial levels. This inventory serves many purposes: it fulfills Canada’s international reporting obligations under the 1979 Convention on Long-range Transboundary Air Pollution (CLRTAP) and the associated protocols ratified by Canada for the reduction of emissions of sulphur oxides (SOx), nitrogen oxides (NOx), cadmium (Cd), lead (Pb), mercury (Hg), volatile organic compounds (VOCs), dioxins and furans, and other persistent organic pollutants (POPs). The APEI also reports emissions of additional air pollutants not covered by protocols including ammonia (NH3), carbon monoxide (CO), fine particulate matter (PM2.5), coarse particulate matter (PM10) and total particulate matter (TPM). In addition, the APEI supports monitoring and reporting obligations under the Canada-U.S. Air Quality Agreement and the development of air quality management strategies, policies and regulations, provides data for air quality forecasting, and informs Canadians about pollutants that affect their health and the environment.

While the APEI provides valuable information on emissions within Canada, air quality issues may arise from localized emissions; information on these emissions are aggregated with all other emissions at the provincial and territorial level in the APEI.

The APEI is compiled from many different data sources. Emissions data reported by individual facilities to Environment and Climate Change Canada’s National Pollutant Release Inventory (NPRI) and, to a lesser extent, data provided directly by the provinces are supplemented with well documented, science-based estimation tools and methodologies to quantify total emissions. Together, these data sources provide a comprehensive coverage of air pollutant emissions across Canada.

This edition of the APEI Report summarizes the most recent estimates of air pollutant emissions for 1990–2017 as of February 2019. The inventory indicates that 14 of the 17 reported air pollutants show decreases compared to historical levels, and specifically indicate that:Footnote 1

  • emissions of SOx were 0.9 million tonnes in 2017, 35% below the emission ceiling of 1.45 million tonnes established under the 1999 Gothenburg Protocol to Abate Acidification, Eutrophication and Ground-level Ozone
  • emissions of NOx were 1.8 million tonnes in 2017, 21% below the emission ceiling of 2.25 million tonnes established under the 1999 Gothenburg Protocol
  • in 2017, emissions of non-methane VOCs were 14% below the emission ceiling of 2.1 million tonnes established under the 1999 Gothenburg Protocol
  • in 2017, emissions of Cd, Pb, and Hg were 85%, 72% and 82% below the ceilings established under the 1998 Aarhus Protocol on Heavy Metals
  • in 2017, emissions of all POPs were below the ceilings established under the 1998 Aarhus Protocol on Persistent Organic Pollutants, including the four species of polycyclic aromatic hydrocarbons (PAHs) (69% below), hexachlorobenzene (HCB) (92% below), and dioxins and furans (85% below)
  • carbon monoxide (CO) decreased by 54% from 1990 to 2017
  • fine particulate emissions (particulate matter less than or equal to 2.5 microns in diameter [PM2.5]) decreased from all sources except from dust from paved and unpaved roads, agriculture fuel use, as well as construction operations, with total PM2.5 emissions in 2017 being 15% below 1990 levels

Canada’s air pollution emission trends (1990 to 2017)

The last year saw no significant change in the general downward trend in pollutant emissions. Industrial emissions of SOx continued to decline, largely due to decreasing emissions from the oil and gas industry, and were down 52% from 1990 levels. Emissions from non-ferrous refining and smelting were down 79% from 1990 levels and electric power generation (utilities) were down 60%.

Improved agricultural practices and the adoption of more recent wood combustion equipment also contributed to a 15% decrease in emissions of PM2.5.

A few sources of pollutants exerted a dominant influence in the downward trends in emissions. In particular, decreases in emissions of SOx, Cd, Pb, Hg and PAH from non-ferrous refining and smelting and from mining and rock quarrying strongly contributed to the overall downward trends in emissions of these pollutants. In addition, reductions in NOx emissions from light-duty gasoline trucks and vehicles, as well as in VOC and CO emissions associated with the combustion of gasoline, liquid petroleum gas or natural gas by off-road equipment were instrumental in reducing national emissions of these pollutants.

Improvements in incineration technologies contributed significantly to decreases in emissions of HCB, dioxins and furans. The 11% increase in PM10 emissions since 1990 constrast with the general trends decribed above; it is largely due to increased transportation on paved and unpaved roads as well as construction operations. another exception to the general downward trends is the observed increase in emissions of ammonia (NH3), which were 19% above 1990 levels in 2017; the upward trend in ammonia emissions is driven by fertilizer application and animal production.

Irrespective of the downward trends observed in Canadian emissions, localized air issues may still arise when emissions sources are spatially concentrated.

Canada’s air emissions regulations and measures

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

All regulations administered under CEPA are available on the 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 aluminum, iron, steel and ilmenite, iron ore pellets, potash, pulp and paper, base-metals smelting sectors.

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