Caribou Meat Research Articles

Locating the Boundaries of the Nuclear North: Arctic Biology, Contaminated Caribou, and the Problem of the Threshold.

This essay is a historical–geographical account of how scientists and public health officials conceptualized and assessed northern radioactive exposures in the late 1950s and 1960s. The detection of radionuclides in caribou bodies in northern Canada both demonstrated the global reach of nuclear fallout and revealed the unevenness of toxic relations and radioactive exposures. Following the documentation of the lichen–caribou–human pathway of exposure, Canadian public health officials became increasingly concerned about the possibility of heightened radioactive exposures among Indigenous northerners. Between 1963 and 1969, scientists and officials with Canada’s Radiation Protection Division (RPD) coordinated an interdepartmental monitoring program through which they sought to determine whether the consumption of contaminated caribou meat had caused radioactive exposure levels in northern communities to exceed the officially recognized “safe limits.” In 1969, the northern monitoring program was suspended after officials determined that radionuclide body burdens had not exceeded the threshold for radioactive exposures. While the RPD emphasized its development of a technoscientific approach to measuring radioactive body burdens, the legitimacy of the monitoring program was linked directly to interdepartmental relations within Canada’s colonial northern administration. I situate the northern monitoring program within broader shifts in public health approaches to radiation protection and use Gabrielle Hecht’s concept of nuclearity to demonstrate how RPD officials employed the logic of the threshold in their assessment of radioactive exposures.

Big game cervid meat as a potential good source of plasmalogens for functional foods

Plasmalogen deficiency is associated with increased risks for diabetes mellitus, cancer, cardiac and respiratory diseases, and more recently Alzheimer’s disease (AD). Diet remains one of the most important sources of plasmalogen for humans. There is increasing interest in finding unique natural sources of plasmalogen to be used in the development of functional foods, as well as to improve plasmalogen intake during normal food consumption. Big game cervids meat is gaining popularity as a superior source of protein with enhanced levels of functional lipids. Herein, we show that moose (Alces alces) and caribou (Rangifer tarandus) contain high levels of plasmalogens in their polar lipid composition, e.g., 50–59 % of plasmalogen phosphatidylcholine (pPC) and 56–61 % plasmalogen phosphatidylethanolamine (pPE). Caribou was found to be rich in plasmalogen pPC content (59 %), while moose was dominant in plasmalogen pPE content (61 %). Moose meat is characterized by having ten-folds higher concentration of lyso-plasmalogen pLPE at 417 ± 55 μg/g as compared to 42 ± 4 μg/g and 36 ± 7 μg/g in caribou meat and moose antler, respectively. The phospholipid composition with high plasmalogen content reported in caribou and moose meat/antler suggests that they may serve as natural dietary sources of plasmalogens during normal food consumption.

Microbiota in foods from Inuit traditional hunting.

The foods we eat contain microorganisms that we ingest alongside the food. Industrialized food systems offer great advantages from a safety point of view, but have also been accused of depleting the diversity of the human microbiota with negative implications for human health. In contrast, artisanal traditional foods are potential sources of a diverse food microbiota. Traditional foods of the Greenlandic Inuit are comprised of animal-sourced foods prepared in the natural environment and are often consumed raw. These foods, some of which are on the verge of extinction, have not previously been microbiologically characterized. We mapped the microbiota of foods stemming from traditional Inuit land-based hunting activities. The foods included in the current study are dried muskox and caribou meat, caribou rumen and intestinal content as well as larval parasites from caribou hides, all traditional Inuit foods. This study shows that traditional drying methods are efficient for limiting microbial growth through desiccation. The results also show the rumen content of the caribou to be a highly diverse source of microbes with potential for degradation of plants. Finally, a number of parasites were shown to be included in the biodiversity of the assessed traditional foods. Taken together, the results map out a diverse source of ingested microbes and parasites that originate from the natural environment. These results have implications for understanding the nature-sourced traditional Inuit diet, which is in contrast to current day diet recommendations as well as modern industrialized food systems.

Discovery of Enteric Pathogens in the Alaskan Subsistence Diet

Abstract Objectives Transmission of enteric pathogens from food ingestion is an ongoing public health concern, with commensal bacteria in ruminant animal species causing human disease. Enteric pathogens Salmonella, Shigella, and Shiga toxin producing Escherichia coli (STEC) have been isolated from domesticated animals. However, the Alaskan subsistence diet relies on wild game, such as reindeer, caribou, and moose for their food supply. Research concerning enteric pathogens in wildlife has not established. Therefore, we conducted a pilot survey on moose and reindeer to determine potential enteric pathogen transfer risk. Methods Between July 2018 and January 2019, we collected 72 fecal samples from reindeer and moose migrating in Fairbanks, Anchorage, and the Matanuska Valley. Samples were cultured for enteric pathogens, including E coli 0157, using standard clinical microbial process. Phenotypic Shiga toxin production was verified by enzyme immunoassay. Results Reindeer were statistically significant for enteric pathogens when compared to moose (P < .05) Eighty percent of the reindeer population were colonized for either Shigella, Yersinia, or Shiga toxin-producing E coli, with 20% positive for multiple pathogens. Non-0157 Shiga toxin production was observed in 30% of reindeer samples, generated by a sorbitol fermenting E coli. In contrast, moose population showed a near absence of enteric pathogens with only 5% positive for Shigella. Salmonella was not identified in either animal. Conclusion Reindeer, moose, and caribou meat are prominent in the Alaskan subsistence diet. Although moose had limited enteric pathogen colonization, reindeer were significant for transmission risk, including non-0157 Shiga toxin producing E coli, which has been linked to hemolytic uremic syndrome. Isolation of a non-0157 STEC in wildlife indicates environmental colonization. Because reindeer and caribou are closely linked in diet and migration, Alaska clinical laboratories should screen for enteric pathogens, including non-0157 Shiga toxins.

Potential impact of restricted caribou (Rangifer tarandus) consumption on anemia prevalence among Inuit adults in northern Canada

BackgroundCaribou (Rangifer tarandus) is the top dietary source of iron and several micronutrients necessary for red blood cell production (erythropoiesis) in the contemporary diet of Inuit adults across Canada. Many caribou populations across the circumpolar north, however, have experienced dramatic declines in recent decades. Restricted access to caribou may negatively impact the nutrition and health of Inuit communities.MethodsWe used data from the Inuit Health Survey, a cross-sectional survey of 2550 Inuit adults in thirty-six communities across northern Canada (conducted in 2007–2008) to examine the relationship between caribou consumption, hemoglobin (Hb), and blood biomarkers of nutrient intake and contaminant exposure. Multivariable linear regression was used to investigate the potential public health impact of a theoretical restriction in caribou consumption, by estimating the response of Hb concentrations (and the attendant change in anemia prevalence), to theoretical changes in caribou consumption (with and without substitution of caribou with other country food meat).ResultsMean (95% CI) daily caribou meat consumption differed by an order of magnitude 4.3 (3.9–4.7), 51.1 (48.5-53.8), and 236.7 (224.7–248.7) grams/day between tertiles of caribou consumption. Mean (95% CI) hemoglobin levels increased from 129.1 (128.1–130.2) g/L to 132.5 (131.3–133.7) g/L between the highest and lowest tertiles of caribou consumption. In multivariable regression analyses, average daily caribou meat consumption was positively associated (P< 0.001) with hemoglobin levels. This relationship translated into approximately 4 g/L hemoglobin increase in participants in the third tertile of caribou consumption. The overall prevalence of anemia observed in the study population was 26.5% (24.5 – 28.3%) and a modelled restriction in caribou consumption (i.e. caribou = 0) increased the overall prevalence of anemia by approximately 6%. The maximum negative effect of caribou restrictions was related to a complete restriction on caribou consumption, coupled with the substitution of caribou with other country food meat (35.4% prevalence).ConclusionsGiven the importance of caribou to Inuit culture, health and wellbeing, and the high price of healthful market foods in remote northern communities, strategies to promote the sustainable harvest of country foods are urgently required to ensure the health and nutrition security of the Inuit, in the context of rapidly changing Arctic environments and ecosystems.

Application of a weight of evidence approach to evaluating risks associated with subsistence caribou consumption near a lead/zinc mine

Overland transport of ore concentrate from the Red Dog lead/zinc mine in northwest Alaska to its seaport has historically raised concerns among local subsistence users regarding the potential impacts of fugitive dust from the operation, including the potential uptake of metals into caribou meat. Caribou are an integral part of life for northern Alaska Natives for both subsistence and cultural reasons. The Western Arctic caribou herd, whose range includes the Red Dog mine, transportation corridor, and port site, sometimes overwinter in the vicinity of mine operations. A weight of evidence approach using multiple lines of evidence was used to evaluate potential risks associated with subsistence consumption of caribou harvested near the road and mine. Data from a long-term caribou monitoring program indicate a lack of consistent trends for either increasing or decreasing metals concentrations in caribou muscle, liver, and kidney tissue. Lead, cadmium, and zinc from all tissues were within the range of reference concentrations reported for caribou elsewhere in Northern Alaska. In addition, a site use study based on data from satellite-collared caribou from the Western Arctic Herd showed that caribou utilize the area near the road, port, and mine approximately 1/20th to 1/90th of the time assumed in a human health risk assessment conducted for the site, implying that risks were significantly overestimated in the risk assessment. The results from multiple lines of evidence consistently indicate that fugitive dust emissions from Red Dog Operations are not a significant source of metals in caribou, and that caribou remain safe for human consumption.

Caribou consumption in northern Canadian communities

ABSTRACTChronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) found in both farmed and wild deer, elk, and moose in the United States and Canada. Surveillance efforts in North America identified the geographical distribution of the disease and mechanisms underlying distribution, although the possibility of transmission to other cervids, including caribou, and noncervids, including humans, is not well understood. Because of the documented importance of caribou (Rangifer tarandus) to human populations in the northern regions of Canada, a risk-management strategy for CWD requires an understanding of the extent of potential dietary exposure to CWD. Secondary 24-h dietary recalls conducted among Inuvialuit and Inuit in 4 communities in the Northwest Territories and Nunavut were employed in this study. Econometric demand systems were estimated to model the impacts of individual- and community-level socioeconomic characteristics on expenditures on caribou and other foods, in order to examine the households’ ability to consume other foods in response to changing levels of caribou consumption. Thirty-five percent of respondents reported consuming caribou in the survey period, and caribou comprised, on average, 26% of daily dietary intake by weight, or approximately 65 g/d, across individuals in the 4 communities. Consuming caribou was also shown to exert positive impacts on dietary quality, as measured by calorie intake and dietary diversity. Communities with less access to employment, income and food stores are predicted to be constrained in their ability to obtain an adequate diet in the event of scarcity of caribou meat.

The Legend of Lightning and Thunder P. I. Rumbolt

Rumbolt, Paula Ikuutaq. The Legend of Lightning and Thunder. Iqualuit, NV: Inhabit Media, 2013. Print.There are many Inuit stories that tell of the origins of things. There are also many stories about orphans. This book is a simple retelling of a legend that involves both and carries a gentle lesson. It concludes that the presence of thunder and lightning in our world is the result of people neglecting and not caring for orphan children. Paula Ikuutaq Rumbolt is an Inuit writer from Baker Lake, Nunavut. She learned traditional Inuit stories and beliefs from her grandmother. The story is from “a time before stealing existed. No one knew what it was, as it had never happened to anyone.” When the orphan children are turned away from the camp, they must steal food to stay alive, which makes them permanent outcasts. They steal caribou meat, a small caribou skin and a flint. They discover that the skin will make noise and the flint will make sparks and have fun playing with them. They soon realize, though, that they will be hunted by the people in the camp so they hide in the sky, where you can hear them today, playing with the skin and the flint, making thunder and lightning. While the text is fairly easy to read, the presence of more difficult words such as “exhilarating” indicates that it is really intended to be shared by an adult and child.While the story is simple, it is brought to life by Jo Rioux’s artwork. For each pair of pages, one is a full page comic-book style image showing Inuit people in village settings and doing traditional activities. The facing page has a smaller image, with text usually printed over a light coloured sky. The images are in a palette of soft browns and oranges, which shade to reds, particularly where magical things are being depicted. Young children will enjoy this book, as will anyone who appreciates Inuit legends. This volume extends Inhabit Media's track record of consistently high quality publications and authentic voices and sources. Highly recommended for elementary school and public libraries.Highly recommended: 4 stars out of 4 Reviewer: Sandy CampbellSandy is a Health Sciences Librarian at the University of Alberta, who has written hundreds of book reviews across many disciplines. Sandy thinks that sharing books with children is one of the greatest gifts anyone can give.

Consumption of tomato products is associated with lower blood mercury levels in Inuit preschool children

Some evidence suggests that various diet components and nutrients, including vegetables, fruit and food-derived antioxidants, could mitigate contaminant exposure and/or adverse health effects of contaminants. To examine the effect of the consumption of tomato products on blood mercury levels in Inuit preschool children, 155 Inuit children (25.0±9.1months) were recruited from 2006–2008 in Nunavik childcare centers (northern Québec, Canada). Food frequency questionnaires were completed at home and at the childcare center, and total blood mercury concentration was measured by inductively coupled plasma-mass spectrometry. Multivariate regression analysis was performed after multiple imputation. The median blood concentration of mercury was 9.5nmol/L. Age, duration of breastfeeding, annual consumption frequency of seal meat, and monthly consumption frequency of tomato products were significant predictors of blood mercury levels, whereas annual consumption frequencies of beluga muktuk, walrus, Arctic char, and caribou meat were not. Each time a participant consumed tomato products during the month before the interview was associated with a 4.6% lower blood mercury level (p=0.0005). All other significant predictors in the model were positively associated with blood mercury levels. Further studies should explore interactions between consumption of healthy store-bought foods available in Arctic regions and contaminant exposure.

Mercury hair concentrations and dietary exposure among Inuit preschool children in Nunavut, Canada

There is concern that the traditional diet is a source of mercury exposure among Inuit in the Canadian Arctic. Mercury exposure in utero and in early childhood presents a risk to neurodevelopment. The objectives of the present study were to assess the dietary mercury exposure from traditional food among Inuit children 3 to 5 years of age in Nunavut, and evaluate the association between estimated dietary mercury intake and body burden. A cross-sectional Nunavut Inuit Child Health Survey was conducted in 2007 and 2008 which included assessment of dietary habits and children's hair mercury (Hg) levels. Further, an Inuit Adult Health Survey was conducted in the same years which included assessment of dietary habits and whole blood mercury concentrations. Traditional food samples were collected during this study and previously from the Canadian Arctic. Daily mercury intake from traditional food was calculated. Body mercury burden was determined using the hair mercury concentration. The geometric mean of children's hair Hg was 0.66 μg/g and varied by region. Nearly 25% of children had hair Hg concentrations equal to or higher than 2 μg/g (WHO reference level). There was a significant correlation between mercury levels in children's hair and that of the adults in the same household. For children, beluga muktuk, narwhal muktuk, ringed seal liver, fish, caribou meat and ringed seal meat were the major dietary sources of mercury. These food items together accounted for over 95% of total daily dietary mercury intake. A positive linear regression relationship between children's hair mercury levels and estimated dietary mercury intake was observed. Estimated intake in Baffin decreased by 30% compared to 20 years ago. Some traditional food items were significant sources of mercury to Inuit children in Nunavut. Although a reduction in the consumption of these diet items may be a way to reduce mercury intake, the nutritional, social and cultural benefits of traditional food and countervailing risks must be taken into account in risk mitigation.

Estimated dietary exposure to fluorinated compounds from traditional foods among Inuit in Nunavut, Canada

Increasing evidence shows that persistent organic pollutants such as perfluorinated compounds (PFCs) are found in the Arctic ecosystem and their prevalence is causing human health concerns. The objective of this study was to estimate dietary exposure to PFCs among Inuit in northern Canada. Perfluorooctane sulfonate (PFOS), perfluorinated carboxylates (PFCA C 7–C 11) and fluorotelomer unsaturated carboxylic acids (6:2, 8:2 and 10:2 FTUCA) were measured in 68 traditional foods collected in Nunavut between 1997 and 1999. Total PFC concentrations were highest in caribou liver (mean ± standard deviation; 6.2 ± 5.5 ng g −1), ringed seal liver (minimum, maximum; 7.7, 10.2 ng g −1), polar bear meat (7.0 ng g −1), and beluga meat (minimum, maximum; 7.0, 5.8 ng g −1). Inuit food intake data from 24-h recalls conducted in Nunavut between 1997 and 1999 were used for the calculation of PFC exposure. Mean daily dietary exposure was calculated to range from 210 to 610 ng person −1 (0.6–8.5 ng kg body weight −1) for 754 individuals. Dietary exposure to PFCs was statistically significantly higher in men in the 41–60 year age group ( p < 0.05) than younger men (<40 years old) and women from the same age group. Traditional foods contributed a higher percentage to PFC exposure than market foods in all age and gender groups. Caribou meat contributed 43–75% of daily PFC dietary exposure. Health risks associated with these estimated exposure levels are minimal based on current toxicological information available from animal feeding studies. However, it is important to monitor the concentrations of PFCs in key food items given that PFCA levels have been found to be increasing in the Canadian Arctic.

Serological Evidence of Hepatitis E Virus Infection in an Indigenous North American Population

Hepatitis E virus (HEV) infections are thought to be uncommon in North America. Recently, HEV transmission has been reported following the consumption of deer meat. Because deer are closely related to caribou and caribou meat is a staple of the Canadian Inuit and the American Eskimo diet, the present study explored the seroprevalence of HEV infection in an isolated Canadian Inuit community. Stored sera were thawed and tested for immunoglobulin (Ig) G and IgM anti-HEV by ELISA, and tested for HEV-RNA by reverse transcriptase polymerase chain reaction. The study consisted of 393 sera (representing approximately 50% of the community's inhabitants). Eleven samples (3%) were IgG anti-HEV-positive. Their mean age was 29+/-8 years and three were male. Two of 11 (18%) were also IgM anti-HEV-positive. All IgG anti-HEV-positive individuals were HEV-RNA-negative. Liver biochemistry was normal in all. Seven of 11 (64%) were also positive for anti-hepatitis A virus, five (46%) were hepatitis B virus seropositive and none (0%) were positive for anti-hepatitis C virus. There were no associations between infections with HEV and other hepatropic viruses. Serological testing was negative for HEV infection in 25 caribou from an adjacent region. The results of the present study showed that serological evidence of HEV infection was present in 3% of the observed Canadian Inuit population; the presence of IgM anti-HEV suggested recent infection and HEV did not appear to coinfect with other common hepatotropic viruses. The source of HEV infection in the population remains unclear. These findings are interesting but preliminary. Additional data are required to determine whether HEV infections are responsible for otherwise unexplained acute hepatitis in the Canadian Inuit population and visitors returning from northern North American communities.

The Inuit commercial caribou harvest and related agri-food industries in Nunavut

The commercial caribou harvesting and related agri-food processing industries in Nunavut have grown global since 1995. These industries have a significant impact on Nunavut's GDP, add key infrastructure, and foster self-reliance and employment for Inuit people in Rankin Inlet and Coral Harbour. The caribou hunt occurs once per year and is the largest in the world. This case focuses on Kivalliq Arctic Foods and Coral Harbour Development Corporation and the local harvesting and processing of Nunavut's caribou meat products. Kivalliq's caribou meat products are exported to clients in the USA as well as the European Union. Both Kivalliq's processing plant and Coral Harbour's portable abattoir have received European Union Certification. The case discusses how the companies used quality assurance, aboriginal branding, e-commerce, and international trade shows to overcome barriers resulting from their northern isolation.

Prevalence of Toxoplasma gondii antibodies in barren-ground caribou (Rangifer tarandus groenlandicus) from the Canadian Arctic.

Prevalence of antibodies to Toxoplasma gondii was determined in 147 barren-ground caribou (Rangifer tarandus groenlandicus) from 5 herds in the Northwest Territories and Nunavut, northern Canada, by the modified agglutination test (MAT). In the mainland herds (Bluenose, Bathurst, and Beverly), antibodies were found in 43 (37%) of 117 caribou, and MAT titers were 1:25 in 10, 1:50 in 24, and 1:500 in 9. In the island herds, only 1 (4.3%) of 23 animals sampled from the North Baffin Island herd was positive (titer = 1:25) and no antibodies were detected in 7 caribou from the Dolphin and Union herd. The high prevalence of antibodies to T. gondii in the mainland caribou herds indicates that caribou meat may contain viable T. gondii.

A Method for Estimating Caribou Consumption by Northern Canadians

Caribou is an important source of protein in the diet of northern Canadians. It is also an important pathway for airborne environmental contaminants that concentrate in the lichen - caribou - human food chain. We present a method for estimating caribou consumption that is independent of questionnaires and dietary surveys. The method is based on direct, whole-body measurements of fallout radiocesium in northern caribou consumers and on measurements of the concentrations of radiocesium in the meat. From the 1989-90 surveys of five Arctic communities, we obtained the following mean (90th percentile) intakes of caribou meat in grams per day: Baker Lake - males 65 (141), females 41 (88); Rae-Edzo - males 42 (103), females 31 (80); Old Crow - males 41 (108), females 23 (59); Fort McPherson - males 41 (77), females 32 (68); Aklavik - males 20 (47), females 15 (37). Compared with surveys carried out in the late 1960s, these values indicate a twofold to fourfold decrease in caribou consumption over a period of 20 years. A dietary survey questionnaire administered during the 1989-90 survey provided useful information on the consumption of various caribou organs, methods of meat preparation, and consumption of other traditional foods.

Radionuclides in the lichen-caribou-human food chain near uranium mining operations in northern Saskatchewan, Canada.

The richest uranium ore bodies ever discovered (Cigar Lake and McArthur River) are presently under development in northeastern Saskatchewan. This subarctic region is also home to several operating uranium mines and aboriginal communities, partly dependent upon caribou for subsistence. Because of concerns over mining impacts and the efficient transfer of airborne radionuclides through the lichen-caribou-human food chain, radionuclides were analyzed in tissues from 18 barren-ground caribou (Rangifer tarandus groenlandicus). Radionuclides included uranium (U), radium (226Ra), lead (210Pb), and polonium (210Po) from the uranium decay series; the fission product (137Cs) from fallout; and naturally occurring potassium (40K). Natural background radiation doses average 2-4 mSv/year from cosmic rays, external gamma rays, radon inhalation, and ingestion of food items. The ingestion of 210Po and 137Cs when caribou are consumed adds to these background doses. The dose increment was 0.85 mSv/year for adults who consumed 100 g of caribou meat per day and up to 1.7 mSv/year if one liver and 10 kidneys per year were also consumed. We discuss the cancer risk from these doses. Concentration ratios (CRs), relating caribou tissues to lichens or rumen (stomach) contents, were calculated to estimate food chain transfer. The CRs for caribou muscle ranged from 1 to 16% for U, 6 to 25% for 226Ra, 1 to 2% for 210Pb, 6 to 26% for 210Po, 260 to 370% for 137Cs, and 76 to 130% for 40K, with 137Cs biomagnifying by a factor of 3-4. These CRs are useful in predicting caribou meat concentrations from the lichens, measured in monitoring programs, for the future evaluation of uranium mining impacts on this critical food chain.

Radionuclides in the Lichen-Caribou-Human Food Chain near Uranium Mining Operations in Northern Saskatchewan, Canada

The richest uranium ore bodies ever discovered (Cigar Lake and McArthur River) are presently under development in northeastern Saskatchewan. This subarctic region is also home to several operating uranium mines and aboriginal communities, partly dependent upon caribou for subsistence. Because of concerns over mining impacts and the efficient transfer of airborne radionuclides through the lichen-caribou-human food chain, radionuclides were analyzed in tissues from 18 barren-ground caribou (Rangifer tarandus groenlandicus). Radionuclides included uranium (U), radium (226Ra), lead (210Pb), and polonium (210Po) from the uranium decay series; the fission product (137Cs) from fallout; and naturally occurring potassium (40K). Natural background radiation doses average 2-4 mSv/year from cosmic rays, external gamma rays, radon inhalation, and ingestion of food items. The ingestion of 210Po and 137Cs when caribou are consumed adds to these background doses. The dose increment was 0.85 mSv/year for adults who consumed 100 g of caribou meat per day and up to 1.7 mSv/year if one liver and 10 kidneys per year were also consumed. We discuss the cancer risk from these doses. Concentration ratios (CRs), relating caribou tissues to lichens or rumen (stomach) contents, were calculated to estimate food chain transfer. The CRs for caribou muscle ranged from 1 to 16% for U, 6 to 25% for 226Ra, 1 to 2% for 210Pb, 6 to 26% for 210Po, 260 to 370% for 137Cs, and 76 to 130% for 40K, with 137Cs biomagnifying by a factor of 3-4. These CRs are useful in predicting caribou meat concentrations from the lichens, measured in monitoring programs, for the future evaluation of uranium mining impacts on this critical food chain.

Assessment of dietary exposure to trace metals in Baffin Inuit food.

Chronic metal toxicity is a concern in the Canadian Arctic because of the findings of high metal levels in wildlife animals and the fact that traditional food constitutes a major component of the diet of indigenous peoples. We examined exposure to trace metals through traditional food resources for Inuit living in the community of Qikiqtarjuaq on Baffin Island in the eastern Arctic. Mercury, cadmium, and lead were determined in local food resources as normally prepared and eaten. Elevated concentrations of mercury ( > 50 micrograms/100 g) were found in ringed seal liver, narwhal mattak, beluga meat, and beluga mattak, and relatively high concentrations of cadmium and lead ( > 100 micrograms/100 g) were found in ringed seal liver, mussels, and kelp. Quantified dietary recalls taken seasonally reflected normal consumption patterns of these food resources by adult men and women ( > 20 years old) and children (3-12 years old). Based on traditional food consumption, the average daily intake levels of total mercury for both adults (65 micrograms for women and 97 micrograms for men) and children (38 micrograms) were higher than the Canadian average value (16 micrograms). The average weekly intake of mercury for all age groups exceeded the intake guidelines (5.0 micrograms/kg/day) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives and Contaminants. The primary foods that contributed to metal intake for the Baffin Inuit were ringed seal meat, caribou meat, and kelp. We review the superior nutritional benefits and potential health risks of traditional food items and implications for monitoring metal contents of food, clinical symptoms, and food use.

Dosimetry of 210Po in humans, caribou, and wolves in northern Canada.

Effective doses from 210Po intake with caribou meat were determined for human residents in Baker Lake and Snowdrift in the Northwest Territories of Canada and compared to doses calculated from reported 210Po tissue activities in Alaskan and British residents (Hill 1966; Blanchard and Moore 1971). Effective doses were calculated to separate body tissues, using ICRP 60 human weighting factors and the ICRP 30 metabolic model for 210Po. Baker Lake and Alaskan effective doses were similar at 0.4 mSv y-1 and slightly higher than Snowdrift doses (0.3 mSv y-1). Alaskan tissue activities indicated higher effective doses to liver, bone surfaces and red marrow and lower doses to spleen than the 210Po metabolic model (ICRP 1979a) predicts. Effective doses to Baker Lake and Snowdrift caribou and wolves, calculated from tissue activities, ranged from 7-20 mSv y-1, using human weighting factors for comparison to human doses only. Effective doses to northern Canadians and wildlife were, respectively, 7-11% and 1.8-5 times an estimated human background of 4 mSv y-1 from all sources.

Human Uptake of Radiocaesium from Caribou Meat

Several kg of caribou meat containing 250 to 280 Bq.kg −1 of 137 Cs were given to each of seven healthy volunteers at the Bureau of Radiation and Medical Devices. Whole-body measurements were carried out until radiocaesium levels were no longer detectable. 137 Cs activities were also measured in successive 24 h urine and faecal samples during an initial short-term phase. The ICRP two-component retention model was essentially confirmed, with 10% of the radiocaesium body burden being excreted with a half-time of about two days, and the remainder with a longer half-time (mean = 86 days; range = 49 to 186 days). Eighty to ninety per cent of excreted radiocaesium appeared in urine. Most importantly, it was confirmed that uptake of radiocaesium by the GI tract was virtually 100%