Archived: Air Pollutant Emission Inventory report: executive summary

Executive summary

Canada’s Air Pollutant Emission Inventory (APEI) has been prepared and published by Environment and Climate Change Canada since 1973. The APEI is a comprehensive inventory of emissions of 17 air pollutants at the national and provincial/territorial levels. This inventory serves many purposes including fulfilling 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 (SO_x), nitrogen oxides (NO_x), cadmium (Cd), lead (Pb), mercury (Hg), dioxins and furans, and other persistent organic pollutants (POPs). 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, informs Canadians about pollutants that affect their health and the environment, and provides data for air quality forecasting models.

The APEI is compiled from many different data sources. Emissions data reporting by individual facilities to Environment and Climate Change Canada’s National Pollutant Release Inventory 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 overview of air pollutant emissions across Canada.

This edition of the APEI Report summarizes the most recent estimates of air pollutant emissions for 1990–2016 as of February 2018. The inventory indicates that 14 of the 17 reported air pollutants show reductions compared to historical levels.^{Footnote 1}  Specifically:

• emissions of SO_x were 1.1 million tonnes in 2016, 67% below the emission ceiling of 3.3 million tonnes established under the 1985 Helsinki Protocol on the Reduction of Sulphur Emissions or their Transboundary Fluxes
• emissions of NO_x were 1.8 million tonnes in 2016, 21% below the emission ceiling of 2.3 million tonnes established under the 1988 Sofia Protocol concerning the Control of Emissions of Nitrogen Oxides or their Transboundary Fluxes
• in 2016, emissions of Cd, Pb, and Hg were 83%, 75% and 76% below the ceilings established under the 1998 Aarhus Protocol on Heavy Metals
• in 2016, emissions of all POPs were below ceilings established in the 1998 Aarhus Protocol on Persistent Organic Pollutants, including the four species of polycyclic aromatic hydrocarbons (PAHs) (by 69%), hexachlorobenzene (HCB) (by 91%), and dioxins and furans (by 88%)
• emissions of non-methane volatile organic compounds (VOCs) and carbon monoxide (CO) decreased by 42% and 54%, respectively, from 1990 to 2016
• fine particulate emissions (particulate matter less than or equal to 2.5 microns in diameter (PM_2.5)) are decreasing from all sources except from dust from paved and unpaved roads, agriculture fuel use, as well as construction; total PM_2.5 emissions are 18% below 1990 levels

Canada’s air pollution emission trends (1990–2016)

The last year saw no significant change in the general downward trend in pollutant emissions: industrial emissions of SO_x continued to decline, largely due to decreasing emissions from the petroleum industry, down 51% since 1990, non-ferrous smelting and refining, down 72% since 1990, and electric power generation (utilities), down 59%.

The adoption of conservation tillage practices in crop production and the use of new fireplace inserts, furnaces and stoves have contributed to a decrease in emissions of PM_2.5, however since 1990 there have been increases in PM_2.5 emissions from paved and unpaved roads, agriculture fuel use, as well as construction operations. Although already on the decline, the aluminium industry experienced a large drop in PAH emissions from 2001 to 2010 due to the implementation of new production technologies, such as the introduction of pre-baked electrodes to replace continuous casting electrodes. Since 2013, the aluminium industry experienced additional decreases, related to the replacement of old smelting equipment with a modern smelter at the facility that has historically contributed the largest portion of PAH emissions. Emissions of Cd continued their steady decline, with reductions in emissions from several sources.

A few sources of pollutants exerted a dominant influence in the downward trends in emissions. In particular, decreases in emissions of SO_x, Cd, Pb and Hg from non-ferrous smelting and refining and from mining and rock quarrying industries strongly contributed to the overall downward trends in emissions of these pollutants. In addition, reductions in NO_x 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 compressed 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.

An exception to the general downward trends described above is the observed increase in emissions of ammonia (NH₃) which were 20% above 1990 levels in 2016. The upward trend in ammonia emissions is driven by fertilizer application and animal production.

Canada’s Air Emissions Regulations

Downward trends in emissions of air pollutants reflect the ongoing implementation of a wide range of regulations that 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 in the registry.