Mercury in Canadians

Information on human biomonitoring of mercury in Canada with results from the Canadian Health Measures Survey.

On this page

• Background
• Data sources
• Results
• Suggested citation
• Additional information

Background

What is mercury?

Mercury (CASRN 7439-97-6) is a naturally occurring metal that is liquid at room temperature. It exists in elemental, inorganic and organic forms and enters the environment through both natural and industrial processes. Mercury persists in the environment and can accumulate over time.

Where is mercury found?

Mercury is present in the environment, even in remote Arctic regions, because it is persistent, mobile and tends to accumulate in colder climates. Canada prohibits the manufacture and import of most mercury-containing products. However, certain essential products are exempt, such as dental amalgams and fluorescent lamps. Mercury is also found in certain foods, such as fish.

How are people exposed to mercury?

Mercury exposure in the general population is mainly through eating larger species of fish. Organic methylmercury is the primary form of exposure in that case. In Arctic communities, eating marine mammals is a major source of mercury. To a lesser extent, the general population is exposed to inorganic mercury from dental amalgams.

How is mercury measured in people?

Mercury is absorbed into the bloodstream after being ingested or inhaled. Mercury in urine is commonly measured to evaluate long-term exposure to its elemental and inorganic forms. Mercury concentrations in blood reflect recent dietary exposure to organic forms, particularly methylmercury.

What are the potential health impacts of mercury?

Exposure to organic mercury may cause neurological effects, including developmental neurotoxicity in fetuses and children. Inhaling mercury vapour may cause respiratory, cardiovascular, kidney and neurological effects. The International Agency for Research on Cancer has classified methylmercury compounds as possibly carcinogenic to humans.

What is the Government of Canada doing to lower human exposures to mercury?

Mercury is identified as toxic under the Canadian Environmental Protection Act, 1999. Mercury is subject to numerous federal risk management initiatives in Canada directed toward industrial releases. The Products Containing Mercury Regulations prohibit the manufacture and import of most mercury-containing products in Canada. However, there are exemptions for a few essential products, such as fluorescent lamps, which are subject to mercury content limits. In addition, regulations under the Canada Consumer Product Safety Act limit the amount of mercury in surface-coating materials. Health Canada has established a methylmercury blood guidance value of 20 µg/L for the general adult population. For children, pregnant women and women of child-bearing age, the provisional methylmercury blood guidance value is 8 µg/L. Health Canada has also established maximum levels for mercury in fish sold to consumers. Guidelines are in place for mercury in Canadian drinking water. The Government of Canada continues to monitor and assess mercury.

Data sources

Table 1. Biomonitoring initiatives and their target populations

Initiative	Target population
Canadian Health Measures Survey (CHMS)	General Canadian population living in the 10 provinces
First Nations Biomonitoring Initiative (FNBI)	First Nations people living on-reserve south of the 60° parallel
Maternal-Infant Research on Environmental Chemicals (MIREC) study	Pregnant women and their infants recruited from obstetric and prenatal clinics in 10 cities across Canada
International Polar Year Inuit Health Survey (IPY IHS)	Inuit populations from the Inuvialuit Settlement Region (ISR), Nunavut and Nunatsiavut
U.S. National Health and Nutrition Examination Survey (NHANES)	General U.S. population

This fact sheet presents nationally representative data from the CHMS. These data are compared with data from the FNBI, the MIREC study, the IPY IHS and the U.S. NHANES.

Table 2. Biomonitoring initiatives and their collection periods, participant age ranges, matrices sampled and biomarkers measured

Collection period	Age range (years)	Matrix	Biomarker
CHMS
2007–2009	6 to 79	Blood	Total mercury
2009–2011	3 to 79	Blood	Total mercury
2012–2013	3 to 79	Blood	Total mercury
2014–2015	3 to 79	Blood	Total mercury
2016–2017	3 to 79	Blood	Total mercury
2018–2019	3 to 79	Blood	Total mercury
FNBI
2011	20+	Blood	Total mercury
MIREC study
2008–2011	18+	Blood	Total mercury
IPY IHS
2007–2008	18+	Blood	Total mercury
U.S. NHANES
2007–2008	1+	Blood	Total mercury
2009–2010	1+	Blood	Total mercury
2011–2012	1+	Blood	Total mercury
2013–2014	1+	Blood	Total mercury
2015–2016	1+	Blood	Total mercury

Results

Canadian population

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in the Canadian population from the CHMS (2007–2019).

Figure 1: Text description

Collection period	Geometric mean
2007–2009	0.88
2009–2011	0.92
2012–2013	0.92
2014–2015	0.70
2016–2017	0.76
2018–2019	0.85

Concentrations of mercury were relatively unchanged in the Canadian population from 2007–2019. There was no statistically significant change over time (P = 0.132).

Canadian population, by age group

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in the Canadian population by age group from the CHMS (2007–2019). Geometric mean mercury concentrations could not be calculated for individuals under 20 years old. This was because too many samples were below the analytical limit of detection.

Figure 2: Text description

Collection period	Age group (years)	Geometric mean
2007–2009	20 to 39	0.72
2007–2009	40 to 59	1.0
2007–2009	60 to 79	0.92
2009–2011	20 to 39	0.71
2009–2011	40 to 59	1.0
2009–2011	60 to 79	1.2
2012–2013	20 to 39	0.82
2012–2013	40 to 59	0.96
2012–2013	60 to 79	1.0
2014–2015	20 to 39	0.55
2014–2015	40 to 59	0.77
2014–2015	60 to 79	0.88
2016–2017	20 to 39	0.61
2016–2017	40 to 59	0.88
2016–2017	60 to 79	0.84
2018–2019	20 to 39	0.78
2018–2019	40 to 59	0.84
2018–2019	60 to 79	0.98

Concentrations of mercury were similar across age groups in the Canadian population.

Canadian population, by sex

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in the Canadian population by sex from the CHMS (2007–2019).

Figure 3: Text description

Collection period	Sex	Geometric mean
2007–2009	Females	0.87
2007–2009	Males	0.90
2009–2011	Females	0.86
2009–2011	Males	0.99
2012–2013	Females	0.94
2012–2013	Males	0.90
2014–2015	Females	0.68
2014–2015	Males	0.73
2016–2017	Females	0.79
2016–2017	Males	0.73
2018–2019	Females	0.83
2018–2019	Males	0.87

Concentrations of mercury were similar between females and males in the Canadian population.

Comparison of the general population and First Nations on-reserve population in Canada

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in the general population aged 20 to 79 from the CHMS (2009–2011) and in the First Nations on-reserve population aged 20 and older from the FNBI (2011).

Figure 4: Text description

Biomonitoring initiative	Geometric mean
CHMS	0.87
FNBI	0.95

Concentrations of mercury were similar between the general population and First Nations on-reserve population in Canada.

Comparison of women of child-bearing age and pregnant women in Canada

This figure shows the geometric mean concentrations of mercury in blood (µg/L) for women of child-bearing age (18 to 49) in the general population from the CHMS (2009–2011) and for women in the first or third trimester of pregnancy from the MIREC study (2008–2011).

Figure 5: Text description

Biomonitoring initiative	Geometric mean
CHMS	0.67
MIREC study (1st trimester)	0.61
MIREC study (3rd trimester)	0.50

Concentrations of mercury were similar between women of child-bearing age and women in the first or third trimester of pregnancy in cities across Canada.

Comparison of the general population and Inuit populations in Canada

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in females and males in the general population aged 18 to 79 from the CHMS (2007–2009) and in Inuit populations aged 18 and older in the ISR, Nunavut and Nunatsiavut from the IPY IHS (2007–2008).

Figure 6: Text description

Biomonitoring initiative	Sex	Geometric mean
CHMS	Females	0.81
CHMS	Males	0.82
IHS (ISR)	Females	4.1
IHS (ISR)	Males	5.6
IHS (Nunavut)	Females	7.9
IHS (Nunavut)	Males	9.4
IHS (Nunatsiavut)	Females	2.8
IHS (Nunatsiavut)	Males	4.2

Concentrations of mercury were higher in Inuit populations in the ISR, Nunavut and Nunatsiavut than in the general population in Canada.

Comparison of the Canadian and U.S. populations

This figure shows the geometric mean concentrations of mercury in blood (µg/L) in the Canadian population from the CHMS (2007–2019) and in the U.S. population from the NHANES (2007–2016). Note that there are slight differences between the surveys in sampling (such as the age ranges of participants) and analysis (such as the limits of detection).

Figure 7: Text description

Biomonitoring initiative	Collection period	Geometric mean
CHMS	2007–2009	0.88
CHMS	2009–2011	0.92
CHMS	2012–2013	0.92
CHMS	2014–2015	0.70
CHMS	2016–2017	0.76
CHMS	2018–2019	0.85
NHANES	2007–2008	0.94
NHANES	2009–2010	1.0
NHANES	2011–2012	0.86
NHANES	2013–2014	0.81
NHANES	2015–2016	0.81

Concentrations of mercury were similar between the Canadian and U.S. populations.

Suggested citation

Health Canada. 2021. Mercury in Canadians. Ottawa, ON. Available: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/environmental-contaminants/human-biomonitoring-resources/mercury-canadians.html

Additional information

• Arbuckle TE, Liang CL, Morisset A-S, Fisher M, Weiler H, Cirtiu CM, Legrand M, Davis K, Ettinger AS, Fraser WD, MIREC Study Group. 2016. Maternal and fetal exposure to cadmium, lead, manganese and mercury: The MIREC study. Chemosphere, 163: 270–282.
• Assembly of First Nations. 2013. First Nations Biomonitoring Initiative: National Results (2011). Ottawa, ON, Canada.
• Centers for Disease Control and Prevention. 2021. National Report on Human Exposure to Environmental Chemicals. Atlanta, GA, USA.
• Crown-Indigenous Relations and Northern Affairs Canada. 2017. Canadian Arctic Contaminants Assessment Report (CACAR IV): Human Health Assessment. Ottawa, ON, Canada.
• Environment Canada and Health Canada. 2010. Risk Management Strategy for Mercury. Ottawa, ON, Canada.
• Government of Canada. 2020. Evaluation of the Effectiveness of Risk Management Measures for Mercury. Ottawa, ON, Canada.
• Health Canada. 2010. Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 1 (2007–2009). Ottawa, ON, Canada.
• Health Canada. 2013. Second Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 2 (2009–2011). Ottawa, ON, Canada.
• Health Canada. 2015. Third Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 3 (2012–2013). Ottawa, ON, Canada.
• Health Canada. 2017. Fourth Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 4 (2014–2015). Ottawa, ON, Canada.
• Health Canada. 2019. Fifth Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 5 (2016–2017). Ottawa, ON, Canada.
• Health Canada. 2021. Sixth Report on Human Biomonitoring of Environmental Chemicals in Canada: Results of the Canadian Health Measures Survey Cycle 6 (2018–2019). Ottawa, ON, Canada.