Releases of Mercury to the Environment

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In 2014, national mercury (Hg) emissions to air from human-related activities totalled 3.9 tonnes (t), which is a 3% (about 0.1 t) decrease from the 2013 level, and a 89% decrease (30.8 t) from 1990, the baseline year of this time series.

On August 4, 2014, a dam securing a tailings pond from the Mount Polley mine in central British Columbia breached, spilling mining waste, including 2.1 t of Hg, into Polley Lake and surrounding waters. As a result, the amount of Hg released to water in 2014 was 2.32 t, about 10 times higher than the 2013 reported level of 0.21 t and a 518% increase (1.95 t) from 2003, the baseline year of this time series.

Releases of mercury to air and water, Canada, 1990 to 2014 (air) and 2003 to 2014 (water)

Line Chart - see long description below

Long description

The line chart shows the amount of mercury emitted to air in Canada between 1990 and 2014 from human-related activities. An insert column chart shows the amount of mercury released to water in Canada between 2003 and 2014. For air, mercury emissions decreased 89% since 1990 while for water an increase of 518% was observed between 2003 and 2014. This increase is explained by the 2014 Mount Polley mine incident in British Columbia.

Data for this chart
Releases of mercury to air and water, Canada, 1990 to 2014 (air) and 2003 to 2014 (water)
YearMercury
(annual national emissions to air in tonnes)
Mercury
(annual national releases to water in tonnes)
199034.7no data
199134.4no data
199234.6no data
199319.9no data
199417.6no data
199514.4no data
199613.9no data
199711.1no data
199810.3no data
199910.0no data
20009.3no data
20019.1no data
20028.7no data
20038.20.38
20048.30.33
20057.90.53
20068.20.34
20079.00.25
20087.80.21
20096.90.34
20105.70.26
20114.20.35
20123.90.18
20134.00.21
20143.92.32

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How this indicator was calculated

Note: The indicator only reports releases from human-related sources. The Hg releases in water indicator includes the amount of elemental Hg in any compound, alloy or mixture reported in the National Pollutant Release Inventory (NPRI) based on the NPRI reporting criteria. As a result, the reported Hg releases to water represent only a portion of the releases of this toxic pollutant to water in Canada.
Source: Environment and Climate Change Canada (2016) Air Pollutant Emission Inventory. Environment and Climate Change Canada (2016) Overview of Reviewed Facility-Reported Data of the National Pollutant Release Inventory (NPRI) 2014.

Mercury is a naturally occurring metal that is used to manufacture products like thermometers, batteries and dental amalgam. Mercury can be emitted to the air by natural processes such as volcanic activity, soil and rock erosion, and by human activities such as metal smelting, iron and steel production, coal-fired electricity generation, industrial boilers, cement kilns, waste incineration, and from the improper disposal of products such as electrical switches and fluorescent lights. Mercury can also be released directly to water by human activities such as pulp and paper production, metals processing and from wastewater treatment.Footnote [1]

Mercury can be transported through the air and deposited into water or onto land. It can be transformed by microorganisms into methylmercury, a toxic form of Hg that is harmful to both humans and wildlife. Methylmercury can bioaccumulate in the food chain and enter our bodies through the ingestion of food containing high levels of mercury, such as predatory fish like freshwater trout or arctic char. Mercury accumulated in vegetation can also be re-emitted to the air during forest fires. Mercury and its compounds are listed as toxicFootnote [2] under the Canadian Environmental Protection Act, 1999 (CEPA 1999).

The large decline in Hg emissions to air since the 1990s is due primarily to changes in facility processes and the adoption of emission-reduction technologies in the non-ferrous smelting and refining sector, the closing of facilities, and compliance with federal and provincial legislation and guidelines introduced over this period. Improvements in fossil fuel-fired electricity generation and incineration also contributed to the decline.

Since 2003 the amount of Hg released to water has been relatively stable, with an increase in 2005, attributed to large release from a single wastewater treatment plant. The increase in 2014 was attributed to the Mount Polley incident in British Columbia.

Mercury emissions to air by source

In 2014, the highest proportion of Hg emissions to air in Canada came from fuel for electricity and heating (mainly from coal combustion), representing about 23% (0.89 t) of the national emissions. Incineration and miscellaneous sources had the second-highest proportion of Hg emissions, with 20% (0.78 t) of national emissions. Releases from waste were the third-largest source representing 16% (0.61 t) of national emissions.. The largest reduction in Hg emissions between the years 1990 and 2014 was from non-ferrous smelting and refining with an emission reduction of 99% (24.6 t).

Mercury emissions to air by source, Canada, 1990 to 2014

Stacked Column Chart - see long description below

Long description

The stacked column chart shows the amount of mercury emitted to air in Canada by source for the years 1990 to 2014. The sources presented are, from bottom to top of each column, fuel for electricity and heating, incineration and miscellaneous, waste, iron and steel industry, other industries, cement and concrete industry, non-ferrous smelting and refining, and other sources. In 2014, the largest mercury emissions came from fuel for electricity and heating with 0.89 tonnes, followed by incineration and miscellaneous sources and waste with 0.78 tonnes and 0.61 tonnes respectively. The largest reduction in emissions between 1990 and 2014 was from non-ferrous smelting and refining with an emission reduction of 99% (24.6 tonnes).

Data for this chart
Mercury emissions to air by source, Canada, 1990 to 2014
YearFuel for electricity and heating
(tonnes)
Incineration and miscellaneous
(tonnes)
Waste
(tonnes)
Iron and steel industry
(tonnes)
Other industries
(tonnes)
Cement and concrete industry
(tonnes)
Non-ferrous smelting and refining
(tonnes)
Other sources
(tonnes)
19902.362.152.400.711.550.4624.900.16
19912.232.182.480.581.530.3824.870.15
19922.472.262.610.441.540.3624.780.16
19932.262.212.490.321.470.3710.630.16
19942.182.242.540.351.450.418.260.16
19952.112.172.820.551.510.414.650.15
19962.231.971.480.481.460.445.680.15
19972.371.631.220.561.360.453.390.15
19982.491.401.010.561.360.452.840.15
19992.491.310.990.971.320.472.280.15
20002.180.991.400.941.310.391.940.15
20012.221.191.220.960.890.372.120.15
20022.201.171.101.040.900.371.750.14
20032.511.190.821.010.920.351.290.14
20042.451.170.780.820.810.221.900.14
20052.301.440.700.660.740.211.700.14
20062.131.350.980.960.920.431.280.14
20072.312.041.010.880.820.331.420.15
20081.761.920.980.870.830.301.010.15
20091.801.570.900.710.710.300.840.11
20101.701.370.590.420.630.320.540.12
20111.140.950.680.460.370.300.210.13
20120.980.750.630.550.370.300.250.13
20130.970.730.550.590.370.310.360.13
20140.890.780.610.590.320.300.290.13

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How this indicator was calculated

Note: The indicator only reports releases from human-related sources. Other sources include transportation, off-road vehicles and home firewood burning. For more details on the sources please consult the Data Source and Methods.
Source: Environment and Climate Change Canada (2016) Air Pollutant Emission Inventory.

Releases of mercury to water by source

Of the 2.32 t of mercury released to water in 2014, 2.14 t was from the Mount Polley incident. Because of this exceptional event, the other industries category contributed 94% (2.18 t) of the total Hg released to water in 2014. The second greatest contribution was from waste, which include wastewater treatment plants.Footnote [3] It was also the source having experienced the largest reduction (0.22 t) between 2003 and 2014.

Releases of mercury to water by source, Canada, 2003 to 2014

Stacked Column Chart - see long description below

Long description

The stacked column chart shows the amount of mercury released to water in Canada by source for the years 2003 to 2014. The sources presented are, from bottom to top of each column, other industries, waste, pulp, paper and paperboard industry, non-ferrous smelting and refining, fuel for electricity and heating, and other sources. In 2014 the other industries source contributed 94% (2.18 tonnes) of the total mercury (2.32 tonnes) released to water in 2014. Second were waste sources, which include wastewater treatment plants. Between 2003 and 2014, the waste sources experienced the largest reduction (0.22 tonnes).

Data for this chart
Releases of mercury to water by source, Canada, 2003 to 2014
YearOther industries
(tonnes)
Waste
(tonnes)
Pulp, paper and paperboard industry
(tonnes)
Non-ferrous smelting and refining
(tonnes)
Fuel for electricity and heating
(tonnes)
Other sources
(tonnes)
20030.010.300.020.010.02< 0.01
20040.020.270.020.010.01< 0.01
20050.010.430.010.050.02< 0.01
20060.010.230.030.060.01no data
20070.020.170.030.030.01< 0.01
20080.020.150.020.010.01< 0.01
20090.070.160.080.010.01no data
20100.020.140.070.020.01no data
20110.100.170.070.01< 0.01no data
20120.030.100.040.01< 0.01no data
20130.040.120.040.01< 0.01no data
20142.180.090.050.01< 0.01no data

Download data file (Excel/CSV; 1.74 KB)

How this indicator was calculated

Note: The indicator only reports releases from human-related sources. The indicator includes the amount of elemental Hg in any compound, alloy or mixture reported in the NPRI based on the NPRI reporting criteria. As a result, the reported Hg releases to water represent only a portion of the releases of this toxic pollutant to water in Canada. Other sources include transportation (road, rail, air, marine). Other industries also include oil and gas industry, iron and steel industry, and cement and concrete industry. For more details on the sources, consult the Data Source and Methods.
Source: Environment and Climate Change Canada (2016) Overview of Reviewed Facility-Reported Data of the National Pollutant Release Inventory (NPRI) 2014.

Mercury emissions to air by province and territory

Ontario had the highest Hg emissions level in 2014, representing 29% (1.13 t) of total national emissions (3.9 t). Mercury emissions in Ontario came mainly from the iron and steel industry, waste sources and the cement and concrete industry. Quebec, with the second-highest emission level, accounts for 20% (0.76 t) of national emissions, mainly from waste sources, incineration, and the non-ferrous smelting and refining industry. Alberta ranked third, with emissions of 0.65 t of Hg; electric power-generating plants were the most important source of emissions in that province.

Mercury emissions to air by province and territory, Canada, 2014[A]

Bar chart - see long description below

Long description

The bar chart shows the amount of mercury emitted to air for provinces and territories that emitted more than 0.1 tonnes in 2014. Ontario with 29% of national emissions was the highest emitting province. Quebec and Alberta followed with 20% and 17% respectively.

Data for this chart
Mercury emissions to air by province and territory, Canada, 2014
Province or territoryMercury emissions
(tonnes)
Percentage of national emissions
Ontario1.1329.0
Quebec0.7619.6
Alberta0.6516.8
Saskatchewan0.5714.6
British Columbia0.369.4
New Brunswick0.164.1
Nova Scotia0.112.8
Manitoba0.071.9
Newfoundland and Labrador0.061.4
Prince Edward Island0.010.3
Northwest Territories< 0.010.1
Yukon< 0.01< 0.1
Nunavut< 0.01< 0.1
Canada3.88100

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How this indicator was calculated

Note: The indicator only reports releases from human-related sources.
[A] Manitoba, Newfoundland and Labrador, Prince Edward Island, the Northwest Territories, Yukon, and Nunavut are not shown in the chart due to their low emissions (≤ 0.1 t).
Source: Environment and Climate Change Canada (2016) Air Pollutant Emission Inventory.

Releases of mercury to water by province and territory

In 2014, because of the Mount Polley mine incident, British Columbia had the largest release of Hg to water with 94% (2.17 t) of the total Hg release. Facilities in Alberta and Ontario were the second and third largest contributors to total Hg release. This is very different from 2013, when nearly 60% of the releases were accounted for by Ontario and Alberta.

Releases of mercury to water by province and territory, Canada, 2013 and 2014[A]

bar chart - see long description below

Long description

The bar chart shows the amount of mercury released to water for provinces and territories that released more than 0.01 tonnes in 2014 with the previous year's releases provided for comparison. In 2014, British Columbia accounted for 94% of the total mercury released to water, followed by Alberta and Ontario with 3% and 1% respectively.

Data for this chart
Releases of mercury to water by province and territory, Canada, 2013 and 2014
Province or territory2013
mercury releases
(tonnes)
2013
percentage of national releases
2014
mercury releases
(tonnes)
2014
percentage of national releases
British Columbia0.0210.92.1793.5
Alberta0.0626.50.073.0
Ontario0.0733.40.031.3
Northwest Territories0.0211.70.020.9
Quebec0.0211.30.020.9
New Brunswick0.015.60.010.3
Manitoba< 0.010.3< 0.01< 0.1
Nova Scotia< 0.010.3< 0.01< 0.1
Newfoundland and Labrador< 0.01<0.1< 0.01< 0.1
Saskatchewan< 0.01<0.1< 0.01< 0.1
Canada0.211002.32100

Download data file (Excel/CSV; 1.44 KB)

How this indicator was calculated

Note: The indicator only reports releases from human-related sources. The indicator includes the amount of elemental Hg in any compound, alloy or mixture reported in the NPRI based on the NPRI reporting criteria. As a result, the Hg releases represent only a portion of the releases of this toxic pollutant to water in Canada.
[A] Prince Edward Island, Yukon and Nunavut did not report releases of Hg to the NPRI in 2014. New Brunswick, Manitoba, Nova Scotia, Newfoundland and Labrador, and Saskatchewan are not shown in the chart due to their low releases (≤ 0.01 t).
Source: Environment and Climate Change Canada (2016) Overview of Reviewed Facility-Reported Data of the National Pollutant Release Inventory (NPRI) 2014.

Releases of mercury from facilities

Environment and Climate Change Canada's NPRI provides detailed information on emissions and releases from industrial and commercial facilities that meet NPRI reporting criteria. The Canadian Environmental Sustainability Indicators (CESI) program provides access to this information through an online interactive map.

With the CESI interactive map, you can zoom in to local areas and obtain details on Hg emissions to air and releases of Hg to water from individual facilities.

Source: Environment and Climate Change Canada (2016) National Pollutant Release Inventory Online Data Search – Facility Reported Data.

Global mercury emissions to air

In 2010, the global emissionsFootnote [4] of Hg to air from human activity were estimated to be 1960 t.

East and Southeast Asia accounted for 39.7% (777 t) of the global total, with China contributing about three quarters of the region's emissions, or approximately one third of the global total. Sub-Saharan Africa ranked second, with 16.1% (316 t), followed by South America, with 12.5% (245 t). South Asia ranked fourth, with 7.9% (154 t), and the Commonwealth of Independent States (CIS)Footnote [5] and other European countries (excluding members of the European Union) ranked fifth, with 5.9% (115 t). Canada emitted less than 5 t in 2010,Footnote [6] about 0.3% of the global Hg emissions to air.

Global mercury emissions to air, 2010

bar chart - see long description below

Long description

The bar chart shows the amount of mercury emitted to air in 2010 from different regions of the world.

Data for this chart
Global mercury emissions to air, 2010
RegionsMercury emissions
(tonnes)
Percentage of global emissions
East and Southeast Asia777.039.7
Sub-Saharan Africa316.016.1
South America245.012.5
South Asia154.07.9
Commonwealth of Independent States (CIS) and other European countries115.05.9
European Union (EU27)87.54.5
North America60.73.1
Central America and the Caribbean47.22.4
Middle Eastern States37.01.9
Australia, New Zealand & Oceania22.31.1
North Africa13.60.7
Undefined82.04.2

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How this indicator was calculated

Note: The CIS includes Azerbaijan, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russian Federation, Tajikistan, Turkmenistan, Uzbekistan and Ukraine. The Undefined region includes emissions from contaminated sites.
Source: United Nations Environmental Program (UNEP) Chemicals Branch (2013) Global Mercury Assessment 2013: Sources, emissions, releases, and environmental transport.

Mercury emissions can travel hundreds to thousands of kilometres via air masses before being deposited.Footnote [7] For example, transboundary flows of Hg emissions from foreign sources accounted for over 95% of the anthropogenic Hg deposited in Canada in 2006.Footnote [8]

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