Canada’s Air Pollutant Emissions Inventory Report 2022: chapter 2.9

2.9 Mercury (Hg)

Approximately 3.0 t of mercury (Hg) were emitted in Canada in 2020 (Table 2–11). Ore and Mineral Industries accounted for 37% (1.1 t) of Hg emissions in 2020, with the Iron and Steel Industry sector contributing 16% (0.49 t) of the national total. Incineration and Waste sources accounted for 26% (0.79 t) of Hg emissions in 2020, with Crematoriums being the largest contributor at 20% (0.61 t). Electric Power Generation (Utilities) accounted for 16% (0.50 t) of 2020 emissions, most of which were emitted from coal-powered electric generation with 16% (0.48 t) of the annual total.

Between 1990 and 2020, Hg emissions decreased by 91% (31 t) (Figure 2–9). This decrease in emissions is mainly due to a large drop in emissions from the Non-Ferrous Refining and Smelting Industry sector. As with Pb and Cd emissions, reductions in Hg emissions coincide with the closure of outdated smelters, the implementation of pollution prevention plans, achieving BLIERs for particulate matter through Environmental Performance Agreements, increased emission control measures, such as changing feedstocks, improved particulate matter emission controls and fuel switching (ECCC, 2017, 2018a). For the Incineration and Waste source category, decreases in emissions from 1990 to 2020 resulted from a reduction of Hg emissions reported by incineration facilities as well as a result of a reduction in Hg in products, such as dental amalgams and mercury-containing lamps, going into the waste stream. Emission reductions from Electric Power Generation (Utilities) are largely due to the closure of coal-fired electricity generation facilities and from the addition of Hg controls to plants. Coal electric power generation also experienced a Hg emission decrease of 16% (95 kg) between the years 2019 and 2020, attributed to plant closures and a decrease in coal consumption. 

The most significant changes in Hg emissions from 1990 to 2020 include:

• Ore and Mineral Industry: decrease of 96% (25 t), with:
  • Non-Ferrous Refining and Smelting Industry: decrease of 99% (25 t)
• Incineration and Waste: decrease of 69% (1.8 t), with:
  • Waste Incineration: decrease of 94% (1.5 t)
  • Waste Treatment and Disposal: decrease of 89% (0.73 t)
• Electric Power Generation (Utilities): decrease of 78% (1.8 t), with:
  • Coal: decrease of 75% (1.5 t)

Figure 2–9: Trends in Canadian Hg emissions (1990 to 2020)

Table 2–11: National summary of annual Hg emissions

Notes:
Totals may not add up due to rounding.
0.00 Indicates emissions were truncated due to rounding.
- Indicates no emissions

Note:
Refer to Annex 4.4 for more information on international marine navigation and air transportation reporting emissions.