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Concentrations of mercury in tissues of beluga whales (Delphinapterus leucas) from several communities in the Canadian Arctic from 1981 to 2002.

https://arctichealth.org/en/permalink/ahliterature6626
Source
Sci Total Environ. 2005 Dec 1;351-352:391-412
Publication Type
Article
Date
Dec-1-2005
Author
W L Lockhart
G A Stern
R. Wagemann
R V Hunt
D A Metner
J. DeLaronde
B. Dunn
R E A Stewart
C K Hyatt
L. Harwood
K. Mount
Author Affiliation
Department of Fisheries and Oceans, Winnipeg, Manitoba, Canada.
Source
Sci Total Environ. 2005 Dec 1;351-352:391-412
Date
Dec-1-2005
Language
English
Publication Type
Article
Keywords
Animals
Arctic Regions
Beluga Whale - metabolism
Canada
Environmental monitoring
Female
Food Contamination
Humans
Kidney - chemistry - metabolism
Liver - chemistry - metabolism
Male
Mercury - analysis - metabolism
Muscles - chemistry - metabolism
Research Support, Non-U.S. Gov't
Selenium - analysis
Skin - chemistry - metabolism
Tissue Distribution
Water Pollutants, Chemical - analysis - metabolism
Abstract
Beluga whales have been hunted for food by Native People in the Canadian Arctic since prehistoric time. Here we report the results of analyses of total mercury in samples of liver, kidney, muscle and muktuk from collections over the period 1981-2002. We compare these results with human consumption guidelines and examine temporal and geographic variation. Liver has been analyzed more frequently than other organs and it has been used as the indicator organ. Mercury accumulates in the liver of the whales over time so that the whale ages are usually linked statistically to their levels of mercury in liver. Virtually all the samples of 566 animals analyzed contained mercury in liver at concentrations higher than the Canadian consumption guideline of 0.5 microg g-1 (wet weight) for fish. (There is no regulatory guideline for concentrations in marine mammals in Canada.) Samples from locations in the Mackenzie Delta in the western Canadian Arctic and from Pangnirtung in the eastern Canadian Arctic were obtained more often than from other location and these offered the best chances to determine whether levels have changed over time. Statistical outlier points were removed and the regressions of (ln) mercury in liver on age were used to calculate the level of mercury in whales of age 13.1 years in order to compare age-adjusted levels at different locations. These age-adjusted levels and also the slopes of regressions suggested that levels have increased in the Mackenzie Delta over the sampling period although not in a simple linear fashion. Other locations had fewer collections, generally spread over fewer years. Some of them indicated differences between sampling times but we could not establish whether these differences were simply temporal variation or whether they were segments of a consistent trend. For example, the levels in whales from Arviat were considerably higher in 1999 than in 1984 but we have only two samples. Similarly, samples from Iqaluit in 1994 exceeded considerably those in 1993 and the interval seems too short to reflect any regional temporal trend and more likely represent an extreme case of year-to-year variation. Previous analyses of data from geographically distinct groups had suggested that whales in the western Canadian Arctic had higher levels of mercury than those from the eastern Canadian Arctic. The present analysis suggests that such regional differences have diminished and are no longer statistically significant. No site has indicated significant decreases in more recent samples. The levels of total mercury in the most analyzed organs fell in the order of liver (highest levels), kidney, muscle and muktuk (lowest level). While muktuk had the lowest level of the organs most frequently analyzed, it is the preferred food item from these whales and it still exceeded the consumption guideline in most instances.
PubMed ID
16055166 View in PubMed
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Contaminants in the Canadian Arctic: 5 years of progress in understanding sources, occurrence and pathways.

https://arctichealth.org/en/permalink/ahliterature197975
Source
Sci Total Environ. 2000 Jun 1;254(2-3):93-234
Publication Type
Article
Date
Jun-1-2000
Author
R W Macdonal
L A Barrie
T F Bidleman
M L Diamond
D J Gregor
R G Semkin
W M Strachan
Y F Li
F. Wania
M. Alaee
L B Alexeeva
S M Backus
R. Bailey
J M Bewers
C. Gobeil
C J Halsall
T. Harner
J T Hoff
L M Jantunen
W L Lockhart
D. Mackay
D C Muir
J. Pudykiewicz
K J Reimer
J N Smith
G A Stern
Author Affiliation
Institute of Ocean Sciences, Department of Fisheries and Oceans, Sidney, BC, Canada. macdonaldrob@dfo-mpo.gc.ca
Source
Sci Total Environ. 2000 Jun 1;254(2-3):93-234
Date
Jun-1-2000
Language
English
Publication Type
Article
Keywords
Animals
Arctic Regions
Canada
Ecosystem
Environmental Pollutants - analysis - metabolism
Environmental pollution
Humans
Hydrocarbons, Chlorinated - analysis
Pesticides - analysis
Polycyclic Hydrocarbons, Aromatic - analysis
Radioisotopes - analysis
Abstract
Recent studies of contaminants under the Canadian Northern Contaminants Program (NCP) have substantially enhanced our understanding of the pathways by which contaminants enter Canada's Arctic and move through terrestrial and marine ecosystems there. Building on a previous review (Barrie et al., Arctic contaminants: sources, occurrence and pathways. Sci Total Environ 1992:1-74), we highlight new knowledge developed under the NCP on the sources, occurrence and pathways of contaminants (organochlorines, Hg, Pb and Cd, PAHs, artificial radionuclides). Starting from the global scale, we examine emission histories and sources for selected contaminants focussing especially on the organochlorines. Physical and chemical properties, transport processes in the environment (e.g. winds, currents, partitioning), and models are then used to identify, understand and illustrate the connection between the contaminant sources in industrial and agricultural regions to the south and the eventual arrival of contaminants in remote regions of the Arctic. Within the Arctic, we examine how contaminants impinge on marine and terrestrial pathways and how they are subsequently either removed to sinks or remain where they can enter the biosphere. As a way to focus this synthesis on key concerns of northern residents, a number of special topics are examined including: a mass balance for HCH and toxaphene (CHBs) in the Arctic Ocean; a comparison of PCB sources within Canada's Arctic (Dew Line Sites) with PCBs imported through long-range transport; an evaluation of concerns posed by three priority metals--Hg, Pb and Cd; an evaluation of the risks from artificial radionuclides in the ocean; a review of what is known about new-generation pesticides that are replacing the organochlorines; and a comparison of natural vs. anthropogenic sources of PAH in the Arctic. The research and syntheses provide compelling evidence for close connectivity between the global emission of contaminants from industrial and agricultural activities and the Arctic. For semi-volatile compounds that partition strongly into cold water (e.g. HCH) we have seen an inevitable loading of Arctic aquatic reservoirs. Drastic HCH emission reductions have been rapidly followed by reduced atmospheric burdens with the result that the major reservoir and transport agent has become the ocean. In the Arctic, it will take decades for the upper ocean to clear itself of HCH. For compounds that partition strongly onto particles, and for which the soil reservoir is most important (e.g. PCBs), we have seen a delay in their arrival in the Arctic and some fractionation toward more volatile compounds (e.g. lower-chlorinated PCBs). Despite banning the production of PCB in the 1970s, and despite decreases of PCBs in environmental compartments in temperate regions, the Arctic presently shows little evidence of reduced PCB loadings. We anticipate a delay in PCB reductions in the Arctic and environmental lifetimes measured in decades. Although artificial radionuclides have caused great concern due to their direct disposal on Russian Shelves, they are found to pose little threat to Canadian waters and, indeed, much of the radionuclide inventory can be explained as remnant global fallout, which was sharply curtailed in the 1960s, and waste emissions released under license by the European reprocessing plants. Although Cd poses a human dietary concern both for terrestrial and marine mammals, we find little evidence that Cd in marine systems has been impacted by human activities. There is evidence of contaminant Pb in the Arctic, but loadings appear presently to be decreasing due to source controls (e.g. removal of Pb from gasoline) in Europe and North America. Of the metals, Hg provokes the greatest concern; loadings appear to be increasing in the Arctic due to global human activities, but such loadings are not evenly distributed nor are the pathways by which they enter and move within the Arctic well understood.
PubMed ID
10885446 View in PubMed
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A history of total mercury in edible muscle of fish from lakes in northern Canada.

https://arctichealth.org/en/permalink/ahliterature172838
Source
Sci Total Environ. 2005 Dec 1;351-352:427-63
Publication Type
Article
Date
Dec-1-2005
Author
W L Lockhart
G A Stern
G. Low
M. Hendzel
G. Boila
P. Roach
M S Evans
B N Billeck
J. DeLaronde
S. Friesen
K. Kidd
S. Atkins
D C G Muir
M. Stoddart
G. Stephens
S. Stephenson
S. Harbicht
N. Snowshoe
B. Grey
S. Thompson
N. DeGraff
Author Affiliation
North-South Consultants Inc., 833 Harstone Road, Winnipeg, Manitoba, Canada R3R 1E1.
Source
Sci Total Environ. 2005 Dec 1;351-352:427-63
Date
Dec-1-2005
Language
English
Publication Type
Article
Keywords
Animals
Canada
Environmental monitoring
Fishes
Food Contamination
Fresh Water
Geological Phenomena
Geology
Humans
Mercury - analysis - standards
Muscles - chemistry
Risk assessment
Water Pollutants, Chemical - analysis - standards
Abstract
Subsistence fishing has been an important source of food for Native People in northern Canada since prehistoric time. Measurements of the levels of mercury in edible muscle of northern fish have been undertaken for over three decades in efforts to evaluate the risks of consuming northern fish. This report summarizes the data obtained from 7974 fish of 25 species from sites distributed from the Yukon to Labrador. The most abundant species were lake trout, lake whitefish, arctic char, walleye, northern pike and burbot. The question being asked was essentially "Are the fish safe to eat?" The results were used to support decisions on fishing and consumption of fish. They were sorted in several ways, into concentration ranges corresponding to human consumption guidelines, into political jurisdictions and into types of bedrock geology. Overall walleye, northern pike and lake trout, usually exceeded the subsistence consumption guideline of 0.2 microg g-1 total mercury and often exceeded the higher guideline of 0.5 microg g-1 total mercury for commercial sales of fish. Mercury in burbot, another facultative predator, was often lower but several still exceeding a guideline. Arctic char collections were mostly from anadromous populations and these had very low levels of mercury, presumably reflecting marine food sources. Lake whitefish were among the cleanest fish examined with 69 of 81 collections falling in the lowest range. Most collections were from sites in sedimentary rock. However a few sites were in metamorphic, intrusive or volcanic rocks and these, taken together, tended to have a higher proportion of sites in the higher ranges of mercury. These results indicate a widespread problem with mercury in subsistence fisheries for predator species of fish with the problem being most problematic for Nunavut.
PubMed ID
16169059 View in PubMed
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Implications of chemical contaminants for aquatic animals in the Canadian arctic: some review comments.

https://arctichealth.org/en/permalink/ahliterature215991
Source
Sci Total Environ. 1995 Jan 15;160-161:631-41
Publication Type
Article
Date
Jan-15-1995
Author
W L Lockhart
Author Affiliation
Canada Department of Fisheries and Oceans, Winnipeg, Manitoba.
Source
Sci Total Environ. 1995 Jan 15;160-161:631-41
Date
Jan-15-1995
Language
English
Publication Type
Article
Keywords
Animals
Arctic Regions
Biological Markers - analysis
Body Burden
Canada
Cytochrome P-450 Enzyme System - metabolism
Environmental Monitoring - methods
Humans
Water Pollutants, Chemical - adverse effects - analysis
Abstract
Chemical residue analyses have established beyond doubt that arctic ecosystems are contaminated with low concentrations of several contaminants. The sources of these vary, but for many, the principal source is atmospheric deposition as a result of widespread dispersal by air masses carrying materials from lower latitudes. The principal problem discussed here is how to determine whether there are biological implications associated with the contaminants. For the most part, concentrations are below those found in more temperate regions where similar questions have been asked. Little experimental toxicology has been done with arctic species, and relatively little has been done in environmental toxicology in general to express biological responses in terms of body residues. It is argued that chemical residue studies are not, in themselves, evidence of biological responses. The effects of greatest interest are those at ecological levels, but ecological surveys that might detect biological changes have little power to test for cause-effect linkages between the contaminants and the changes observed. The emerging approach of biomarkers or bioindicators seems to offer the greatest promise for efforts to determine whether arctic contaminants have biological implications.
PubMed ID
7892589 View in PubMed
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Mercury species in the liver of ringed seals.

https://arctichealth.org/en/permalink/ahliterature4832
Source
Sci Total Environ. 2000 Oct 16;261(1-3):21-32
Publication Type
Article
Date
Oct-16-2000
Author
R. Wagemann
E. Trebacz
G. Boila
W L Lockhart
Author Affiliation
Department of Fisheries and Oceans, Central and Arctic Region, Freshwater Institute, Winnipeg, Manitoba, Canada.
Source
Sci Total Environ. 2000 Oct 16;261(1-3):21-32
Date
Oct-16-2000
Language
English
Publication Type
Article
Keywords
Animals
Diet
Environmental monitoring
Half-Life
Liver - chemistry
Mercury - analysis - pharmacokinetics
Methylmercury Compounds - analysis - pharmacokinetics
Research Support, Non-U.S. Gov't
Seals, Earless
Tissue Distribution
Water Pollutants, Chemical - analysis - pharmacokinetics
Abstract
Four types of mercury species, namely, methylmercury, organic mercury other than methylmercury, inorganic mercury, and insoluble mercury, deemed to be mercuric selenide (HgSe), were found in the liver of 45 ringed seals from the Canadian Arctic. On average, methylmercury, at 2%, made up the smallest fraction of the total mercury in the liver of these animals. Of the total mercury concentration in seal liver, 53% was insoluble mercury, estimated to be largely mercuric selenide. Other workers have found this compound to be present in mammalian liver and identified it to be HgSe. Organic mercury other than methylmercury made up 4%, and inorganic mercury 42% of the total mercury in the liver. The sum of the independently determined mercury species agreed well with the total mercury concentration in the liver. Species other than mercuric selenide are known to be toxic. Mercuric selenide, considered to be a stable end product of the demethylation process of methylmercury, although not readily eliminated from the liver, is inert and apparently non-toxic. Only approximately half of the total mercury in the liver was potentially toxic mercury. All four mercury species were positively correlated with the age of animals, the regression slope on age being 20 times larger for insoluble Hg (HgSe) than for methylmercury. A number of reported observations, such as the long half-life of Hg in liver (> or = 10 years), the dependence of Hg on age, and the often-observed one-to-one relationship between Hg and Se (on a molar basis), are readily explained by the temporal accumulation of HgSe in the liver. In the future, a more accurate assessment of the health risk to animals and humans from the consumption of contaminated animal tissues will be possible, by measuring all mercury species rather than just total mercury or methylmercury. Total mercury alone in the liver is an inadequate indicator of toxicity to animals. Methylmercury was analyzed by capillary gas-liquid chromatography with ECD detection, and the other species were operationally/experimentally defined using physical/chemical methods.
PubMed ID
11036974 View in PubMed
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Methylmercury and total mercury in tissues of arctic marine mammals.

https://arctichealth.org/en/permalink/ahliterature6806
Source
Sci Total Environ. 1998 Jul 11;218(1):19-31
Publication Type
Article
Date
Jul-11-1998
Author
R. Wagemann
E. Trebacz
G. Boila
W L Lockhart
Author Affiliation
Department of Fisheries and Oceans, Central and Arctic Region, Freshwater Institute, Winnipeg, Manitoba, Canada.
Source
Sci Total Environ. 1998 Jul 11;218(1):19-31
Date
Jul-11-1998
Language
English
Publication Type
Article
Keywords
Adipose Tissue - chemistry
Animals
Arctic Regions
Environmental Pollutants - analysis
Food contamination - analysis
Humans
Liver - chemistry
Meat - analysis
Mercury - analysis
Methylmercury compounds - analysis
Muscles - chemistry
Research Support, Non-U.S. Gov't
Risk factors
Seals, Earless - metabolism
Selenium - analysis
Skin - chemistry
Tissue Distribution
Whales - metabolism
Abstract
Concentrations of methylmercury, total mercury and selenium in marine mammal tissues were determined in liver, muscle, skin (muktuk) and blubber of belugas, ringed seals and narwhal, using atomic absorption and capillary gas chromatography with ECD detection. Mean MeHg levels in the types of tissues analysed, except blubber, generally exceeded the Canadian Federal Consumption Guideline for mercury in fish (0.5 micrograms/g wet wt.). A spatial trend of higher MeHg levels in western compared to eastern Arctic belugas and ringed seals was found which followed a similar trend observed for total mercury. Factors which could explain this trend are discussed. Robust linear regression of MeHg on total Hg and MeHg on age of animals was performed and a strong correlation between the two variables was found in each case. The ratio of MeHg to total mercury as indicated by the regression coefficients was close to one for muscle and skin (muktuk) while for liver it was
PubMed ID
9718742 View in PubMed
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Presence and implications of chemical contaminants in the freshwaters of the Canadian Arctic.

https://arctichealth.org/en/permalink/ahliterature223416
Source
Sci Total Environ. 1992 Jul 15;122(1-2):165-245
Publication Type
Article
Date
Jul-15-1992
Author
W L Lockhart
R. Wagemann
B. Tracey
D. Sutherland
D J Thomas
Author Affiliation
Department of Fisheries and Oceans, Freshwater Institute, Winnipeg, Manitoba, Canada.
Source
Sci Total Environ. 1992 Jul 15;122(1-2):165-245
Date
Jul-15-1992
Language
English
Publication Type
Article
Keywords
Animals
Arctic Regions
Birds - metabolism
Canada
Fishes - metabolism
Fresh Water - chemistry
Humans
Hydrocarbons - analysis - toxicity
Hydrocarbons, Chlorinated - analysis - toxicity
Mammals - metabolism
Metals - analysis - toxicity
Mining
Petroleum
Radioactive Pollutants - analysis - toxicity
Water Pollutants, Chemical - analysis - toxicity
Abstract
Hydrocarbons, stable organochlorines, metals and radionuclides are widespread in the freshwaters of the Canadian Arctic. Petroleum-associated hydrocarbon sources include natural seepage, wastes and effluents from exploration, production and refining at Norman Wells and spills. Hydrocarbons also originate from combustion of carbon-based fuels, generally at lower latitudes and then reach the Arctic with air movements. Organochlorine compounds also move throughout the hemisphere by aerial pathways and have become distributed widely in Arctic fish. The organochlorine at highest concentration in Arctic freshwater is alpha-HCH, while those generally at highest concentrations in the fish are toxaphene, PCBs and chlordane. Metals are ubiquitous in Arctic freshwaters, with inputs of several metals by precipitation superimposed on natural geologic backgrounds. Mercury is found in muscle of fish from Arctic freshwaters at concentrations up to about 0.5 ppm. Radionuclides are also widespread at levels below those acceptable in food, with some local elevations near former mines. The implications of these contaminants for the northern ecosystems and the people dependent upon them are still not clear. Preliminary studies of inducible enzymes in fish suggest that the thresholds for biological damage have not been reached.
PubMed ID
1514104 View in PubMed
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7 records – page 1 of 1.