Contaminants

Caribou, like many Arctic species, are vulnerable to the accumulation of contaminants from global and local sources.

People who eat caribou are concerned about the effects of this contamination, so there is a Canadian government-sponsored program to monitor these contaminants. The Porcupine (western Arctic) and Qamanirjuaq (eastern Arctic) caribou herds have been designated in the Northern Contaminants Program blueprint for annual monitoring of several contaminants including mercury, inorganic elements, PBDEs (polybrominated diphenyl ethers) and PFASs (per- and polyfluoroalkyl substances). The Porcupine caribou have been monitored for contaminants annually since the early 1990s and the Qamanirjuaq since 2006 so there is a good database for studying trends in contaminants in Arctic caribou over time. Other herds have been measured on occasion and give an idea of whether these contaminant loads vary according to location.

PBDEs are chemicals used in flame retardants and are common in the environment. Levels in the Porcupine caribou are very low and have not changed significantly from 2015 through 2017.

PFASs are man-made chemicals that are used in water repellents, stain guards and fire-fighting foams. Levels in caribou liver are low and some varieties of this chemical are declining over time in caribou, likely due to legislation banning their use. The Porcupine caribou did not show elevated levels of radioactivity due to the nuclear accident at Fukushima, Japan in 2011.

Caribou have mercury and cadmium in their kidneys and livers. Some of this is from naturally occurring mercury and cadmium and some is brought north by wind from industry down south.

Caribou muscle (meat), marrow and brain have very low levels of contaminants. Cadmium and mercury in caribou organs fluctuate over time but over the long term are remaining stable.

Mercury is generally higher in the spring than the fall, because the caribou eat lichens through the winter which are higher in mercury than their summer foods of grasses and flowering plants. Mushrooms may provide a pulse of mercury in the fall, because some mushrooms can accumulate large amounts of mercury and are a preferred food when they are available. Seaweed does not provide a significant amount of mercury to the Qamanirjuaq caribou. Mercury concentrations are higher in caribou cows than in bulls, because cows are smaller and eat proportionally more food, therefore more mercury. In the spring, mercury may be lower in cows than in bulls, because some of the mercury is lost to the fetus and through milk production. Mercury in caribou may be affected by rain, snow, wind, temperature, migration patterns, time of green-up and forage quality as well as mercury emissions coming from industry, forest fires and volcanoes.

Overall, contaminant levels in caribou are low and caribou meat remains a healthy and nutritious food choice.

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Related resources

Report to the Hunters of the Lorillard Caribou May 2020 - Inuktitut

A brief report in Inuktitut from the Northern Contaminants Program on contaminants in the Lorillard herd. The animals were sampled in 2018. The report concludes, "Although it is difficult to come to any firm conclusions based on only four animals, we can say that contaminant levels in the Lorillard Caribou are similar to those in other Arctic herds. There have been no health advisories issued on any Nunavut caribou."
(2020)

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Barren-groundLorillardPeopleContaminants

Report to the Hunters of the Sanikiluaq Reindeer

A brief report from the Northern Contaminants Program to the people who hunt reindeer in Sanikiluaq. The reports says most contaminants in local reindeer are similar to those found in other caribou herds in the Canadian Arctic, although levels of some contaminants in Sanikiluaq reindeer were slightly higher than average.
(2020)

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PeopleContaminants

Report to the Hunters of the Sanikiluaq Reindeer - Inuktitut

A brief report in Inuktitut from the Northern Contaminants Program to the people who hunt reindeer in Sanikiluaq. The reports says most contaminants in local reindeer are similar to those found in other caribou herds in the Canadian Arctic, although levels of some contaminants in Sanikiluaq reindeer were slightly higher than average.
(2020)

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Format: pdf

PeopleContaminants

Contaminants in Arctic Caribou Synopsis Report 2019-20

A 9 page synopsis report of the Arctic Caribou Contaminant Monitoring Program. The program covers several Arctic herds. It concludes, "Levels of most contaminants measured in caribou kidneys were not of concern toxicologically, although renal [kidney] mercury and cadmium concentrations may cause some concern for human health depending on the quantity of organs consumed. Yukon Health has advised restricting intake of kidney and liver from Yukon caribou, the recommended maximum varying depending on herd (e.g. a maximum of 25 Porcupine cariboukidneys/year). The health advisory confirms that heavy metals are very low in the meat (muscle) from caribouand this remains a healthy food choice. There have been no health advisories issued for caribou in NWT or Nunavut."
Northern contaminants program (2020)

Renal trace elements in barren-ground caribou subpopulations: Temporal trends and differing effects of sex, age and season

An academic paper that looks at the level of some metals in kidneys of some northern caribou. It found that copper levels are decreasing in the caribou kidneys, possibly due to changes in what caribou are eating. The paper concludes, "Declining Cu concentrations in caribou are of concern as low levels could potentially negatively affect reproduction and therefore caribou at a population level."
Science of the Total Environment (2020)

Report to the Hunters of the Qamanirjuaq Caribou May 2020

A brief Northern Contaminants Program report on the Qamanirjuaq caribou herd. The report has not found any significant change in levels of the contaminants monitored in the samples from 2018.
Northern contaminants program (2020)

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Beverly and QaminirjuaqPeopleContaminants

Report to the Hunters of the Qamanirjuaq Caribou May 2020 - Inuktitut

A brief Northern Contaminants Program report in Inuktitut on the Qamanirjuaq caribou herd. The report has not found any significant change in levels of the contaminants monitored in the samples from 2018.
Northern contaminants program (2020)

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Format: pdf

Beverly and QaminirjuaqPeopleContaminants

Report to the Hunters of the Lorillard Caribou May 2020

A brief report from the Northern Contaminants Program on contaminants in the Lorillard herd. The animals were sampled in 2018. The report concludes, "Although it is difficult to come to any firm conclusions based on only four animals, we can say that contaminant levels in the Lorillard Caribou are similar to those in other Arctic herds. There have been no health advisories issued on any Nunavut caribou."
(2020)

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Format: pdf

Barren-groundLorillardPeopleContaminants

Report to the Hunters of the Porcupine Caribou – February 2019

With the help of local hunters, we have been taking samples of the Porcupine caribou since 1991. We collect these samples to study changes in the level of contaminants kidneys and livers of caribou.
(2019)

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PorcupinePeopleContaminants

Synopsis Report 2018/19 Arctic Caribou Contaminant Monitoring Program

This project studies contaminant levels in caribou in the Canadian Arctic to determine if these populations remain healthy (in terms of contaminant loads), whether these important resources remain safe and healthy food choices for northerners and if contaminant levels are changing over time.
(2019)

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PorcupineBeverly and QaminirjuaqPeopleContaminants

Report to the Hunters of the Qamanirjuaq Caribou – Feb 2019

With the help of local hunters, we have been taking kidney, liver and muscle samples of Qamanirjuaq caribou since 2006. We collect these samples to study changes in the levels of contaminants in kidneys and livers of caribou. These contaminants may be carried to the Arctic by wind.
(2019)

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Format: pdf

Beverly and QaminirjuaqBarren-groundPeopleContaminants

Inuktitut summary report on contaminants in the Dolphin and Union caribou herd

A two-page summary report in Inuktitut on contaminants in the Dolphin and Union caribou herd
(2019)

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Dolphin and UnionContaminants

Inuktitut summary report on contaminants in the Ahiak herd

A two-page summary report in Inuktitut on contaminants in the Ahiak caribou herd
(2019)

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Format: pdf

AhiakContaminants

2019 report to the hunters of the Qamanirjuaq herd - Inuktitut

2 page summary report to hunters of the Qamanirjuaq herd in Inuktitut reporting on research into contaminants in the herd.
(2019)

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Beverly and QaminirjuaqPeopleContaminants

2019 report to the hunters of the Dolphin and Union herd

Two-page summary report to hunters of the Dolphin and Union caribou herd on research into contaminants in the herd
(2019)

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Dolphin and UnionContaminants

Report to the Hunters of the Ahiak Caribou – Feb 2019

The Northern Contaminants Program monitors contaminants in Arctic Caribou in Canada.
(2019)

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AhiakPeopleContaminants

Report to the Hunters of the Bluenose West Caribou – Feb 2019

The Northern Contaminants Program monitors contaminants in Arctic Caribou in Canada.
(2019)

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Bluenose WestPeopleContaminants

mercury in seaweed - inuktitut

This two-page plain language summary in Inuktitut talks about mercury in seaweed and other food eaten by caribou in the Qamanirjuaq herd.
(2018)

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Beverly and QaminirjuaqContaminants

Mercury in Seaweed, Lichens and Mushrooms from the Home Range of the Qamanirjuaq Caribou

Qamanirjuaq caribou have higher mercury concentrations than many other Arctic caribou herds. Usually, caribou get most of their mercury from lichens, but local elders described the Qamanirjuaq caribou eating seaweed from the seashore. Since seaweed is known to accumulate some metals, it was hypothesized that the caribou may be getting additional mercury from this source.
(2018)

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Beverly and QaminirjuaqContaminants

Plain Language Summary: Mercury in Seaweed, Lichens and Mushrooms from the Home Range of the Qamanirjuaq Caribou

The Qamanirjuaq caribou have higher mercury concentrations than some other caribou in the Arctic. Usually, caribou get most of the mercury they eat from lichens, but at community meetings in Kivalliq, elders described caribou eating seaweed. Since seaweed absorbs some metals, the caribou may be getting additional mercury from seaweed.
(2018)

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Contaminants

Report to the Hunters of the Kivalliq Region Contaminants in Qamanirjuaq Caribou – September 2017

With the help of local hunters, we have been taking kidney, liver and muscle samples of Qamanirjuaq caribou since 2006. We collect these samples to study changes in the amount of contaminants such as mercury and lead in kidneys of caribou. These contaminants may be carried to the Arctic by wind.
(2017)

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Beverly and QaminirjuaqBarren-groundPeopleContaminants

Measurements of cesium in Arctic beluga and caribou before and after the Fukushima accident of 2011

Concern from northern communities following the Fukushima Daiichi nuclear accident of March 2011 has prompted a reassessment of the safety of their traditional foods with respect to radioactivity levels. To this end, a study was conducted to measure the levels of radionuclides in Arctic caribou (Rangifer tarandus) and beluga (Delphinapterus leucas).
(2016)

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PorcupineThreatsContaminants

Contaminants in two West Greenland caribou populations

Two caribou populations in West Greenland were sampled and the kidneys, liver and muscle analyzed for contaminants, including aluminum, arsenic, cadmium, copper, lead, mercury, selenium and zinc. Although close in proximity, the two populations are topographically separated by an ice cap, which creates different climates and vegetation types in each region. Contaminant levels reflected the differing diets of the two caribou populations.
(2016)

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Contaminants

Assessing risk of mercury exposure and nutritional benefits of consumption of caribou (Rangifer tarandus) in the Vuntut Gwitchin First Nation community of Old Crow, Yukon, Canada

The contamination of traditional foods with chemical pollutants is a challenge to the food security ofAboriginal Peoples.
(2011)

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PorcupinePeopleContaminants

Biomagnification of Perfluorinated Compounds in a Remote Terrestrial Food Chain: Lichen-Caribou-Wolf

The biomagnification behavior of perfluorinated carboxylates (PFCAs) and perfluorinated sulfonates (PFSAs) was studied in terrestrial food webs consisting of lichen and plants, caribou, and wolves from two remote northern areas in Canada. Six PFCAs with eight to thirteen carbons and perfluorooctane sulfonate (PFOS) were regularly detected in all species.
(2011)

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PorcupineBathurstContaminants

Polychlorinated dibenzodioxins, dibenzofurans and non-ortho substituted polychlorinated biphenyls in caribou (Rangifer tarandus) from the Canadian Arctic

The presence of contaminants in the Arctic environment has raised concerns regarding levels in wildlife and possible effects on the health of wildlife populations. In addition, contaminants in wild foods are of particular concern to those people who rely on these foodstuffs for a significant portion of their diet. Among the most toxic contaminants found in the environment are the polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho substituted polychlorinated biphenyls (NOPCBs).
(1995)

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BathurstSouthampton IslandContaminants

Cadmium in caribou and muskoxen from the Canadian Yukon and Northwest Territories

Cadmium, zinc, copper and metallothionein concentrations were measured in liver and kidney tissue of caribou and muskoxen collected from various sites in the Canadian Yukon and Northwest Territories. Cadmium concentrations in caribou tissues were substantially higher than in muskoxen for all age classes and were comparable to concentrations reported for caribou from northern Quebec and Norway.
Canadian Wildlife Service (CWS) (1994)

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PorcupineBeverly and QaminirjuaqBarren-groundContaminants