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Lazarus M, Sekovanić A, Reljić S, Kusak J, Ferenčaković M, Sindičić M, Gomerčić T, Huber Đ. Lead and Other Trace Element Levels in Brains of Croatian Large Terrestrial Carnivores: Influence of Biological and Ecological Factors. TOXICS 2022; 11:4. [PMID: 36668730 PMCID: PMC9865836 DOI: 10.3390/toxics11010004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Trace element pollution can adversely affect the brains of individuals and thus impact the entire population of apex predators, such as large European carnivores. We assessed exposure to prominent neurotoxicants As, Cd, Hg and Pb by measuring their brain stem levels in brown bears (n = 114), grey wolves (n = 8), Eurasian lynx (n = 3), and golden jackals (n = 2) sampled in 2015-2022 in Croatia. The highest of the non-essential elements was the Pb level in the bears' brains (median, Q1-Q3; 11.1, 7.13-24.1 μg/kg wet mass), with 4% of animals, all subadults, exceeding the established normal bovine levels (100 μg/kg wet mass). Species-specific differences were noted for Ca, Cd, Cu, Fe, Pb and Se brain levels. Female brown bears had higher As brain levels than males. Cubs and yearlings had lower brain Cd, but higher Zn, while subadults had higher Cu than adult bears. Hepatic As, Cd, Cu and Hg levels were shown to be a moderate proxy for estimating brain levels in bears (rS = 0.30-0.69). Multiple associations of As, Cd, Hg and Pb with essential elements pointed to a possible interaction and disturbance of brain Ca, Cu, Fe, Se and Zn homeostasis. Non-essential element levels in the brains of four studied species were lower than reported earlier for terrestrial meso-carnivores and humans. The age and sex of animals were highlighted as essential factors in interpreting brain element levels in ecotoxicological studies of large carnivores.
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Affiliation(s)
- Maja Lazarus
- Institute for Medical Research and Occupational Health, 10000 Zagreb, Croatia
| | - Ankica Sekovanić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Slaven Reljić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Josip Kusak
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | | | - Magda Sindičić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Tomislav Gomerčić
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
| | - Đuro Huber
- Faculty of Veterinary Medicine, University of Zagreb, 10000 Zagreb, Croatia
- Institute of Nature Conservation, Polish Academy of Sciences, 31-343 Krakow, Poland
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2
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Lippold A, Boltunov A, Aars J, Andersen M, Blanchet MA, Dietz R, Eulaers I, Morshina TN, Sevastyanov VS, Welker JM, Routti H. Spatial variation in mercury concentrations in polar bear (Ursus maritimus) hair from the Norwegian and Russian Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153572. [PMID: 35121036 DOI: 10.1016/j.scitotenv.2022.153572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
We examined spatial variation in total mercury (THg) concentrations in 100 hair samples collected between 2008 and 2016 from 87 polar bears (Ursus maritimus) from the Norwegian (Svalbard Archipelago, western Barents Sea) and Russian Arctic (Kara Sea, Laptev Sea, and Chukchi Sea). We used latitude and longitude of home range centroid for the Norwegian bears and capture position for the Russian bears to account for the locality. We additionally examined hair stable isotope values of carbon (δ13C) and nitrogen (δ15N) to investigate feeding habits and their possible effect on THg concentrations. Median THg levels in polar bears from the Norwegian Arctic (1.99 μg g-1 dry weight) and the three Russian Arctic regions (1.33-1.75 μg g-1 dry weight) constituted about 25-50% of levels typically reported for the Greenlandic or North American populations. Total Hg concentrations in the Norwegian bears increased with intake of marine and higher trophic prey, while δ13C and δ15N did not explain variation in THg concentrations in the Russian bears. Total Hg levels were higher in northwest compared to southeast Svalbard. δ13C and δ15N values did not show any spatial pattern in the Norwegian Arctic. Total Hg concentrations adjusted for feeding ecology showed similar spatial trends as the measured concentrations. In contrast, within the Russian Arctic, THg levels were rather uniformly distributed, whereas δ13C values increased towards the east and south. The results indicate that Hg exposure in Norwegian and Russian polar bears is at the lower end of the pan-Arctic spectrum, and its spatial variation in the Norwegian and Russian Arctic is not driven by the feeding ecology of polar bears.
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Affiliation(s)
- Anna Lippold
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway
| | - Andrei Boltunov
- Marine Mammal Research and Expedition Centre, 36 Nahimovskiy pr., Moscow 117997, Russia
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway
| | | | - Marie-Anne Blanchet
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway; UiT The Arctic University of Norway, Tromsø 9019, Norway
| | - Rune Dietz
- Aarhus University, Institute of Ecoscience, Arctic Research Centre, Roskilde 4000, Denmark
| | - Igor Eulaers
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway; Aarhus University, Institute of Ecoscience, Arctic Research Centre, Roskilde 4000, Denmark
| | - Tamara N Morshina
- Research and Production Association "Typhoon", 249038 Obninsk, Kaluga Region, Russia
| | | | - Jeffrey M Welker
- University of Alaska Anchorage, Anchorage 99508, United States; University of Oulu, Oulu 90014, Finland; University of the Arctic, Rovaniemi 96460, Finland
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
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3
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Gauthier PT, Blewett TA, Garman ER, Schlekat CE, Middleton ET, Suominen E, Crémazy A. Environmental risk of nickel in aquatic Arctic ecosystems. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 797:148921. [PMID: 34346380 DOI: 10.1016/j.scitotenv.2021.148921] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/18/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
The Arctic faces many environmental challenges, including the continued exploitation of its mineral resources such as nickel (Ni). The responsible development of Ni mining in the Arctic requires establishing a risk assessment framework that accounts for the specificities of this unique region. We set out to conduct preliminary assessments of Ni exposure and effects in aquatic Arctic ecosystems. Our analysis of Ni source and transport processes in the Arctic suggests that fresh, estuarine, coastal, and marine waters are potential Ni-receiving environments, with both pelagic and benthic communities being at risk of exposure. Environmental concentrations of Ni show that sites with elevated Ni concentrations are located near Ni mining operations in freshwater environments, but there is a lack of data for coastal and estuarine environments near such operations. Nickel bioavailability in Arctic freshwaters seems to be mainly driven by dissolved organic carbon (DOC) concentrations with bioavailability being the highest in the High Arctic, where DOC levels are the lowest. However, this assessment is based on bioavailability models developed from non-Arctic species. At present, the lack of chronic Ni toxicity data on Arctic species constitutes the greatest hurdle toward the development of Ni quality standards in this region. Although there are some indications that polar organisms may not be more sensitive to contaminants than non-Arctic species, biological adaptations necessary for life in polar environments may have led to differences in species sensitivities, and this must be addressed in risk assessment frameworks. Finally, Ni polar risk assessment is further complicated by climate change, which affects the Arctic at a faster rate than the rest of the world. Herein we discuss the source, fate, and toxicity of Ni in Arctic aquatic environments, and discuss how climate change effects (e.g., permafrost thawing, increased precipitation, and warming) will influence risk assessments of Ni in the Arctic.
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Affiliation(s)
- Patrick T Gauthier
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2M9, Canada
| | - Tamzin A Blewett
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2M9, Canada
| | | | | | | | - Emily Suominen
- Department of Biological Sciences, University of New Brunswick, Saint John, NB E2L 4L5, Canada
| | - Anne Crémazy
- Department of Biological Sciences, University of New Brunswick, Saint John, NB E2L 4L5, Canada.
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Dominique M, Letcher RJ, Rutter A, Langlois VS. Comparative review of the distribution and burden of contaminants in the body of polar bears. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:32456-32466. [PMID: 32556983 DOI: 10.1007/s11356-020-09193-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 05/05/2020] [Indexed: 06/11/2023]
Abstract
Historical (or legacy) contaminants, such as metals and persistent organic pollutants (POPs; e.g., polychlorinated biphenyls) have been measured in circumpolar subpopulations of polar bears, especially from Hudson Bay, East Greenland, and Svalbard, but substantially less is currently known about new and/or emerging contaminants such as polychlorinated naphthalenes, current-use pesticides, organotins, and polycyclic aromatic compounds (PACs). The polar bear (Ursus maritimus) is an apex Arctic predator that accumulates high levels of bioaccumulative POPs and mercury (Hg), but there is currently no comprehensive profiling of the present knowledge on contaminants in tissue and body compartments in polar bears. Based on current literature reports and data, and including archived museum samples (as far back as the 1300s) and up to 2018, the aim of this review is to utilize available data to examine the comparative distribution and burden of mainly lipophilic contaminants in kidney, liver, fat, and other body compartments, such as milk, blood, and brain. Highlight outcomes from this review include the following: (1) the kidneys are one of the most important tissue depots of contaminants in polar bears; (2) there is a critical lack of data concerning the presence of metals of concern (other than Hg); and (3) there currently are no data available on the concentrations of many newer and emerging contaminants, such as PACs, which is especially relevant given the increasing oil and gas development in regions, such as the Beaufort Sea (Canada). Additionally, given the vulnerability of polar bear populations worldwide, there is a need to develop non-invasive approaches to monitor contaminant exposure in polar bears.
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Affiliation(s)
- Mélanie Dominique
- Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), Québec City, QC, Canada
| | - Robert J Letcher
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada
| | - Allison Rutter
- School of Environmental Studies, Queen's University, Kingston, ON, Canada
| | - Valerie S Langlois
- Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), Québec City, QC, Canada.
- Ecotoxicology and Wildlife Health Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON, Canada.
- Ecotoxicogenomics and Endocrine Disruption, Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), 490, rue de la Couronne, Québec, QC, G1K 9A9, Canada.
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5
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Cáceres-Saez I, Haro D, Blank O, Aguayo-Lobo A, Dougnac C, Arredondo C, Cappozzo HL, Ribeiro Guevara S. Stranded false killer whales, Pseudorca crassidens, in Southern South America reveal potentially dangerous silver concentrations. MARINE POLLUTION BULLETIN 2019; 145:325-333. [PMID: 31590794 DOI: 10.1016/j.marpolbul.2019.05.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/14/2019] [Accepted: 05/21/2019] [Indexed: 06/10/2023]
Abstract
Silver (Ag) is a non-essential metal known to bioaccumulate in aquatic organisms. We determined Ag concentrations in five false killer whales stranded in South America. Silver concentrations (in dry weight basis) range as 6.62-10.78 μg g-1 in liver, 0.008-7.41 μg g-1 in spleen, 0.004-5.71 μg g-1 in testis, 0.757-1.69 μg g-1 in kidney, 0.011-0.078 μg g-1 in lung and < 0.01-0.038 μg g-1 in muscle, whereas in the single samples of uterus and ovary were 0.051 and 0.023 μg g-1; respectively. Overall, Ag concentration in liver and kidney exceeded the cetacean toxic thresholds, proposed as "unhealthy concentrations" and "critically dangerous" in liver and kidney. These results warrant further eco-toxicological studies, to examine biological effects of elevated silver levels for individuals and to assess the species' conservation status with respect to marine pollution.
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Affiliation(s)
- Iris Cáceres-Saez
- Consejo Nacional de Investigaciones Científicas y Técnicas, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Avenida Ángel Gallardo 470, C1405DJR Buenos Aires, Argentina.
| | - Daniela Haro
- Centro Bahía Lomas, Universidad Santo Tomas, Avenida Costanera 01834, Punta Arenas, Chile
| | - Olivia Blank
- Clínica Veterinaria Timaukel y Centro de Rehabilitación de Aves Leñadura (CRAL), José Pithon 01316, Punta Arenas, Chile
| | - Anelio Aguayo-Lobo
- Instituto Antártico Chileno (INACH), Plaza Muñoz Gamero 1055, Punta Arenas, Chile
| | - Catherine Dougnac
- Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Av. Santa Rosa 11735, La Pintana, Santiago, Chile
| | | | - H Luis Cappozzo
- Consejo Nacional de Investigaciones Científicas y Técnicas, Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Avenida Ángel Gallardo 470, C1405DJR Buenos Aires, Argentina
| | - Sergio Ribeiro Guevara
- Laboratorio de Análisis por Activación Neutrónica, Centro Atómico Bariloche, Avenida Bustillo 9500, Bariloche, Argentina
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6
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Hallanger IG, Fuglei E, Yoccoz NG, Pedersen ÅØ, König M, Routti H. Temporal trend of mercury in relation to feeding habits and food availability in arctic foxes (Vulpes lagopus) from Svalbard, Norway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 670:1125-1132. [PMID: 31018428 DOI: 10.1016/j.scitotenv.2019.03.239] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/15/2019] [Accepted: 03/15/2019] [Indexed: 06/09/2023]
Abstract
We investigated the temporal trend of mercury (Hg) in arctic foxes from Svalbard, Norway sampled in the period 1997-2014 (n = 109, from 11 trapping seasons). We used linear models to investigate the effect of trapping season, feeding habits (δ13C), food availability from marine and terrestrial ecosystems (reindeer carcasses and sea ice cover), sex, age and body condition on liver total Hg (THg) levels. Liver THg levels increased in arctic foxes with 7.2% (95% CI: 2.3, 9.6) per year when the concentrations were adjusted for variation of δ13C, sea ice cover, and reindeer carcasses, whereas the raw annual trend was 3.5% (CI: -0.11, 7.2). However, the THg levels in arctic foxes from Svalbard are still lower than other marine mammals. We also demonstrate that arctic fox terrestrial food consumption is important for lowering the overall THg levels in this species.
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Affiliation(s)
- Ingeborg G Hallanger
- Norwegian Polar Institute, Fram Centre, P.O. Box 6606, Langnes, NO-9296 Tromsø, Norway; UiT - The Arctic University of Norway, Dept. of Arctic & Marine Biology, NO-9037 Tromsø, Norway.
| | - Eva Fuglei
- Norwegian Polar Institute, Fram Centre, P.O. Box 6606, Langnes, NO-9296 Tromsø, Norway.
| | - Nigel G Yoccoz
- UiT - The Arctic University of Norway, Dept. of Arctic & Marine Biology, NO-9037 Tromsø, Norway.
| | - Åshild Ø Pedersen
- Norwegian Polar Institute, Fram Centre, P.O. Box 6606, Langnes, NO-9296 Tromsø, Norway.
| | - Max König
- Norwegian Polar Institute, Fram Centre, P.O. Box 6606, Langnes, NO-9296 Tromsø, Norway
| | - Heli Routti
- Norwegian Polar Institute, Fram Centre, P.O. Box 6606, Langnes, NO-9296 Tromsø, Norway.
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7
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Routti H, Atwood TC, Bechshoft T, Boltunov A, Ciesielski TM, Desforges JP, Dietz R, Gabrielsen GW, Jenssen BM, Letcher RJ, McKinney MA, Morris AD, Rigét FF, Sonne C, Styrishave B, Tartu S. State of knowledge on current exposure, fate and potential health effects of contaminants in polar bears from the circumpolar Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 664:1063-1083. [PMID: 30901781 DOI: 10.1016/j.scitotenv.2019.02.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Revised: 02/01/2019] [Accepted: 02/02/2019] [Indexed: 05/03/2023]
Abstract
The polar bear (Ursus maritimus) is among the Arctic species exposed to the highest concentrations of long-range transported bioaccumulative contaminants, such as halogenated organic compounds and mercury. Contaminant exposure is considered to be one of the largest threats to polar bears after the loss of their Arctic sea ice habitat due to climate change. The aim of this review is to provide a comprehensive summary of current exposure, fate, and potential health effects of contaminants in polar bears from the circumpolar Arctic required by the Circumpolar Action Plan for polar bear conservation. Overall results suggest that legacy persistent organic pollutants (POPs) including polychlorinated biphenyls, chlordanes and perfluorooctane sulfonic acid (PFOS), followed by other perfluoroalkyl compounds (e.g. carboxylic acids, PFCAs) and brominated flame retardants, are still the main compounds in polar bears. Concentrations of several legacy POPs that have been banned for decades in most parts of the world have generally declined in polar bears. Current spatial trends of contaminants vary widely between compounds and recent studies suggest increased concentrations of both POPs and PFCAs in certain subpopulations. Correlative field studies, supported by in vitro studies, suggest that contaminant exposure disrupts circulating levels of thyroid hormones and lipid metabolism, and alters neurochemistry in polar bears. Additionally, field and in vitro studies and risk assessments indicate the potential for adverse impacts to polar bear immune functions from exposure to certain contaminants.
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Affiliation(s)
- Heli Routti
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway.
| | - Todd C Atwood
- U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA
| | - Thea Bechshoft
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Andrei Boltunov
- Marine Mammal Research and Expedition Center, 36 Nahimovskiy pr., Moscow 117997, Russia
| | - Tomasz M Ciesielski
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Jean-Pierre Desforges
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Rune Dietz
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | | | - Bjørn M Jenssen
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway; Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark; Department of Arctic Technology, University Centre in Svalbard, PO Box 156, NO-9171 Longyearbyen, Norway
| | - Robert J Letcher
- Ecotoxicology and Wildlife Heath Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario K1A 0H3, Canada
| | - Melissa A McKinney
- Department of Natural Resource Sciences, McGill University, Ste.-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Adam D Morris
- Ecotoxicology and Wildlife Heath Division, Wildlife and Landscape Science Directorate, Environment and Climate Change Canada, National Wildlife Research Centre, Carleton University, 1125 Colonel By Dr., Ottawa, Ontario K1A 0H3, Canada
| | - Frank F Rigét
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Christian Sonne
- Department of Bioscience, Arctic Research Centre (ARC), Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark
| | - Bjarne Styrishave
- Toxicology and Drug Metabolism Group, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen OE, Denmark
| | - Sabrina Tartu
- Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø, Norway
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McKinney MA, Atwood TC, Pedro S, Peacock E. Ecological Change Drives a Decline in Mercury Concentrations in Southern Beaufort Sea Polar Bears. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:7814-7822. [PMID: 28612610 DOI: 10.1021/acs.est.7b00812] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We evaluated total mercury (THg) concentrations and trends in polar bears from the southern Beaufort Sea subpopulation from 2004 to 2011. Hair THg concentrations ranged widely among individuals from 0.6 to 13.3 μg g-1 dry weight (mean: 3.5 ± 0.2 μg g-1). Concentrations differed among sex and age classes: solitary adult females ≈ adult females with cubs ≈ subadults > adult males ≈ yearlings > cubs-of-the-year ≈ 2 year old dependent cubs. No variation was observed between spring and fall samples. For spring-sampled adults, THg concentrations declined by 13% per year, contrasting recent trends observed for other Western Hemispheric Arctic biota. Concentrations also declined by 15% per year considering adult males only, while a slower, nonsignificant decrease of 4.4% per year was found for adult females. Lower THg concentrations were associated with higher body mass index (BMI) and higher proportions of lower trophic position food resources consumed. Because BMI and diet were related, and the relationship to THg was strongest for BMI, trends were re-evaluated adjusting for BMI as the covariate. The adjusted annual decline was not significant. These findings indicate that changes in foraging ecology, not declining environmental concentrations of mercury, are driving short-term declines in THg concentrations in southern Beaufort Sea polar bears.
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Affiliation(s)
- Melissa A McKinney
- Wildlife and Fisheries Conservation Center, Department of Natural Resources and the Environment and Center for Environmental Sciences and Engineering, University of Connecticut , Storrs, Connecticut 06269, United States
| | - Todd C Atwood
- United States Geological Survey, Alaska Science Center , Anchorage, Alaska 99508, United States
| | - Sara Pedro
- Wildlife and Fisheries Conservation Center, Department of Natural Resources and the Environment and Center for Environmental Sciences and Engineering, University of Connecticut , Storrs, Connecticut 06269, United States
| | - Elizabeth Peacock
- United States Geological Survey, Alaska Science Center , Anchorage, Alaska 99508, United States
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Liu HL, Wang YJ, Xuan L, Dang F, Zhou DM. Effects of low-molecular-weight organic acids on the acute lethality, accumulation, and enzyme activity of cadmium in Eisenia fetida in a simulated soil solution. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:1005-1011. [PMID: 27605122 DOI: 10.1002/etc.3618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/07/2015] [Accepted: 09/06/2016] [Indexed: 06/06/2023]
Abstract
In the present study, the effects of low-molecular-weight organic acids (LMWOAs) on the toxicity of cadmium (Cd) to Eisenia fetida were investigated in a simulated soil solution. The LMWOAs protected E. fetida from Cd toxicity, as indicated by the increased median lethal concentration (LC50) values and the increased activity of superoxide dismutase. In addition, Cd concentrations in E. fetida decreased dramatically in the presence of LMWOAs. These results were likely because of the complexation between Cd and LMWOAs, which decreased the bioavailability and consequential toxicity of Cd to E. fetida. Notably, LMWOAs reduced Cd toxicity in decreasing order (ethylenediamine tetraacetic acid [EDTA] > citric acid > oxalic acid > malic acid > acetic acid), which was consistent with the decreasing complexation constants between LMWOAs and Cd. These results advance our understanding of the interactions between Cd and LMWOAs in soil. Environ Toxicol Chem 2017;36:1005-1011. © 2016 SETAC.
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Affiliation(s)
- Hai-Long Liu
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China
- University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Yu-Jun Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China
| | - Liang Xuan
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China
| | - Fei Dang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China
| | - Dong-Mei Zhou
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, People's Republic of China
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Sato I, Yamauchi K, Tsuda S. Long-Term Survey of Cadmium and Lead Contamination in Japanese Black Bears Captured in Iwate Prefecture, Japan. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 97:806-812. [PMID: 27704187 DOI: 10.1007/s00128-016-1942-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 09/29/2016] [Indexed: 06/06/2023]
Abstract
Cadmium and lead were measured in liver and kidney samples of 242 Japanese black bears (Ursus thibetanus japonicus) captured from 1999 to 2014 from two local populations in Japan. The median concentration of cadmium was 0.54 (mean: 0.80) mg/kg-w.w. in liver and 7.7 (mean: 11.8) mg/kg-w.w. in kidney. The median concentration of lead was 0.24 (mean: 0.40) and 0.21 (mean: 0.32) mg/kg-w.w. in liver and kidney, respectively. Bears in the Kita-ou local population had higher concentrations of cadmium and lead than those in the Kitakami Highlands local population. No chronological change was observed in cadmium levels in tissues, but the percentage of bears whose lead levels exceeded 0.5 mg/kg-w.w. has been decreasing in recent years. Countermeasures against lead poisoning in wildlife, which were instituted in 2002, may have contributed to the decrease in lead contamination of the Japanese black bear.
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Affiliation(s)
- Itaru Sato
- Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, 020-8550, Japan.
| | - Kiyoshi Yamauchi
- Research Institute for Environmental Science and Public Health of Iwate Prefecture, Kita-iioka 1-11-16, Morioka, 020-0857, Japan
| | - Shuji Tsuda
- Faculty of Agriculture, Iwate University, Ueda 3-18-8, Morioka, 020-8550, Japan
- Research Institute for Environmental Science and Public Health of Iwate Prefecture, Kita-iioka 1-11-16, Morioka, 020-0857, Japan
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Evers DC, Keane SE, Basu N, Buck D. Evaluating the effectiveness of the Minamata Convention on Mercury: Principles and recommendations for next steps. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:888-903. [PMID: 27425440 DOI: 10.1016/j.scitotenv.2016.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/01/2016] [Accepted: 05/01/2016] [Indexed: 05/04/2023]
Abstract
The Minamata Convention on Mercury is a multilateral environmental agreement that obligates Parties to reduce or control sources of mercury pollution in order to protect human health and the environment. The Convention includes provisions on providing technical assistance and capacity building, particularly for developing countries and countries with economies in transition, to promote its effective implementation. Evaluating the effectiveness of the Convention (as required by Article 22) is a crucial component to ensure that it meets this objective. We describe an approach to measure effectiveness, which includes a suite of short-, medium-, and long-term metrics related to five major mercury control Articles in the Convention, as well as metrics derived from monitoring of mercury in the environment using select bioindicators, including people. The use of existing biotic Hg data will define spatial gradients (e.g., biological mercury hotspots), baselines to develop relevant temporal trends, and an ability to assess risk to taxa and human communities of greatest concern. We also recommend the development of a technical document that describes monitoring options for the Conference of Parties, to provide science-based standardized guidelines for collecting relevant monitoring information, as guided by Article 19.
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Affiliation(s)
- David C Evers
- Biodiversity Research Institute, Portland, Maine, USA.
| | | | | | - David Buck
- Biodiversity Research Institute, Portland, Maine, USA
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McMeans BC, Arts MT, Fisk AT. Impacts of food web structure and feeding behavior on mercury exposure in Greenland Sharks (Somniosus microcephalus). THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 509-510:216-225. [PMID: 24630590 DOI: 10.1016/j.scitotenv.2014.01.128] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/21/2014] [Accepted: 01/30/2014] [Indexed: 06/03/2023]
Abstract
Benthic and pelagic food web components in Cumberland Sound, Canada were explored as sources of total mercury (THg) to Greenland Sharks (Somniosus microcephalus) via both bottom-up food web transfer and top-down shark feeding behavior. Log10THg increased significantly with δ(15)N and trophic position from invertebrates (0.01 ± 0.01 μg · g(-1) [113 ± 1 ng · g(-1)] dw in copepods) to Greenland Sharks (3.54 ± 1.02 μg · g(-1)). The slope of the log10THg vs. δ(15)N linear regression was higher for pelagic compared to benthic food web components (excluding Greenland Sharks, which could not be assigned to either food web), which resulted from THg concentrations being higher at the base of the benthic food web (i.e., in benthic than pelagic primary consumers). However, feeding habitat is unlikely to consistently influence shark THg exposure in Cumberland Sound because THg concentrations did not consistently differ between benthic and pelagic shark prey. Further, size, gender and feeding behavior (inferred from stable isotopes and fatty acids) were unable to significantly explain THg variability among individual Greenland Sharks. Possible reasons for this result include: 1) individual sharks feeding as generalists, 2) high overlap in THg among shark prey, and 3) differences in turnover time between ecological tracers and THg. This first assessment of Greenland Shark THg within an Arctic food web revealed high concentrations consistent with biomagnification, but low ability to explain intra-specific THg variability. Our findings of high THg levels and consumption of multiple prey types, however, suggest that Greenland Sharks acquire THg through a variety of trophic pathways and are a significant contributor to the total biotic THg pool in northern seas.
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Affiliation(s)
- Bailey C McMeans
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4, Canada.
| | - Michael T Arts
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4, Canada; National Water Research Institute, Environment Canada, 867 Lakeshore Road, PO Box 5050, Burlington, Ontario L7R 4A6, Canada
| | - Aaron T Fisk
- Great Lakes Institute for Environmental Research, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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Braune B, Chételat J, Amyot M, Brown T, Clayden M, Evans M, Fisk A, Gaden A, Girard C, Hare A, Kirk J, Lehnherr I, Letcher R, Loseto L, Macdonald R, Mann E, McMeans B, Muir D, O'Driscoll N, Poulain A, Reimer K, Stern G. Mercury in the marine environment of the Canadian Arctic: review of recent findings. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 509-510:67-90. [PMID: 24953756 DOI: 10.1016/j.scitotenv.2014.05.133] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 05/09/2014] [Accepted: 05/27/2014] [Indexed: 06/03/2023]
Abstract
This review summarizes data and information which have been generated on mercury (Hg) in the marine environment of the Canadian Arctic since the previous Canadian Arctic Contaminants Assessment Report (CACAR) was released in 2003. Much new information has been collected on Hg concentrations in marine water, snow and ice in the Canadian Arctic. The first measurements of methylation rates in Arctic seawater indicate that the water column is an important site for Hg methylation. Arctic marine waters were also found to be a substantial source of gaseous Hg to the atmosphere during the ice-free season. High Hg concentrations have been found in marine snow as a result of deposition following atmospheric mercury depletion events, although much of this Hg is photoreduced and re-emitted back to the atmosphere. The most extensive sampling of marine sediments in the Canadian Arctic was carried out in Hudson Bay where sediment total Hg (THg) concentrations were low compared with other marine regions in the circumpolar Arctic. Mass balance models have been developed to provide quantitative estimates of THg fluxes into and out of the Arctic Ocean and Hudson Bay. Several recent studies on Hg biomagnification have improved our understanding of trophic transfer of Hg through marine food webs. Over the past several decades, Hg concentrations have increased in some marine biota, while other populations showed no temporal change. Marine biota also exhibited considerable geographic variation in Hg concentrations with ringed seals, beluga and polar bears from the Beaufort Sea region having higher Hg concentrations compared with other parts of the Canadian Arctic. The drivers of these variable patterns of Hg bioaccumulation, both regionally and temporally, within the Canadian Arctic remain unclear. Further research is needed to identify the underlying processes including the interplay between biogeochemical and food web processes and climate change.
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Affiliation(s)
- Birgit Braune
- Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3.
| | - John Chételat
- Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3
| | - Marc Amyot
- Département de sciences biologiques, Université de Montréal, CP 6128, Succ. Centre-Ville Pavillon Marie-Victorin, Montreal, Quebec, Canada H3C 3 J7
| | - Tanya Brown
- Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, PO Box 6000, Sidney, British Columbia, Canada V8L 4B2; Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, Ontario, Canada K7K 7B4
| | - Meredith Clayden
- Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
| | - Marlene Evans
- Environment Canada, National Water Research Institute, 11 Innovation Blvd., Saskatoon, Saskatchewan, Canada S7N 3H5
| | - Aaron Fisk
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario, Canada N9B 3P4
| | - Ashley Gaden
- Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Catherine Girard
- Département de sciences biologiques, Université de Montréal, CP 6128, Succ. Centre-Ville Pavillon Marie-Victorin, Montreal, Quebec, Canada H3C 3 J7
| | - Alex Hare
- Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Jane Kirk
- Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, Canada L7R 4A6
| | - Igor Lehnherr
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9
| | - Robert Letcher
- Environment Canada, National Wildlife Research Centre, Carleton University, Raven Road, Ottawa, Ontario, Canada K1A 0H3
| | - Lisa Loseto
- Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
| | - Robie Macdonald
- Fisheries and Oceans Canada, Institute of Ocean Sciences, 9860 West Saanich Road, PO Box 6000, Sidney, British Columbia, Canada V8L 4B2
| | - Erin Mann
- Department of Environmental Science, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6
| | - Bailey McMeans
- Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, Ontario, Canada N9B 3P4
| | - Derek Muir
- Environment Canada, Canada Centre for Inland Waters, 867 Lakeshore Road, Burlington, Ontario, Canada L7R 4A6
| | - Nelson O'Driscoll
- Department of Environmental Science, Acadia University, Wolfville, Nova Scotia, Canada B4P 2R6
| | - Alexandre Poulain
- Department of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada K1N 6N5
| | - Ken Reimer
- Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, Ontario, Canada K7K 7B4
| | - Gary Stern
- Centre for Earth Observation Science, 497 Wallace Bldg., University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2; Fisheries and Oceans Canada, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada R3T 2N6
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14
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Scheuhammer A, Braune B, Chan HM, Frouin H, Krey A, Letcher R, Loseto L, Noël M, Ostertag S, Ross P, Wayland M. Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 509-510:91-103. [PMID: 24935263 DOI: 10.1016/j.scitotenv.2014.05.142] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 05/29/2014] [Accepted: 05/29/2014] [Indexed: 05/24/2023]
Abstract
This review summarizes our current state of knowledge regarding the potential biological effects of mercury (Hg) exposure on fish and wildlife in the Canadian Arctic. Although Hg in most freshwater fish from northern Canada was not sufficiently elevated to be of concern, a few lakes in the Northwest Territories and Nunavut contained fish of certain species (e.g. northern pike, Arctic char) whose muscle Hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within which adverse biological effects begin to occur. Marine fish species generally had substantially lower Hg concentrations than freshwater fish; but the Greenland shark, a long-lived predatory species, had mean muscle Hg concentrations exceeding the threshold range for possible effects on health or reproduction. An examination of recent egg Hg concentrations for marine birds from the Canadian Arctic indicated that mean Hg concentration in ivory gulls from Seymour Island fell within the threshold range associated with adverse effects on reproduction in birds. Mercury concentrations in brain tissue of beluga whales and polar bears were generally lower than levels associated with neurotoxicity in mammals, but were sometimes high enough to cause subtle neurochemical changes that can precede overt neurotoxicity. Harbour seals from western Hudson Bay had elevated mean liver Hg concentrations along with comparatively high muscle Hg concentrations indicating potential health effects from methylmercury (MeHg) exposure on this subpopulation. Because current information is generally insufficient to determine with confidence whether Hg exposure is impacting the health of specific fish or wildlife populations in the Canadian Arctic, biological effects studies should comprise a major focus of future Hg research in the Canadian Arctic. Additionally, studies on cellular interactions between Hg and selenium (Se) are required to better account for potential protective effects of Se on Hg toxicity, especially in large predatory Arctic fish, birds, and mammals.
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Affiliation(s)
- Anton Scheuhammer
- Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Birgit Braune
- Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada.
| | - Hing Man Chan
- Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Héloïse Frouin
- Jasco Research, 4464 Markam St., Victoria, BC V8Z 7X8, Canada
| | - Anke Krey
- Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada
| | - Robert Letcher
- Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, ON K1A 0H3, Canada
| | - Lisa Loseto
- Fisheries and Oceans Canada, National Centre for Arctic Aquatic Research Excellence, 501 University Crescent, Winnipeg, MB R3T 2N6, Canada
| | - Marie Noël
- School of Earth and Ocean Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
| | - Sonja Ostertag
- Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada
| | - Peter Ross
- Fisheries and Oceans Canada, Institute of Ocean Sciences, Sidney, BC V8L 4B2, Canada
| | - Mark Wayland
- Environment Canada, Canadian Wildlife Service, 115 Perimeter Rd., Saskatoon, Saskatchewan S7N 0X4, Canada
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Krey A, Kwan M, Chan HM. In vivo and in vitro changes in neurochemical parameters related to mercury concentrations from specific brain regions of polar bears (Ursus maritimus). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2014; 33:2463-2471. [PMID: 25264143 DOI: 10.1002/etc.2685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/27/2014] [Accepted: 07/11/2014] [Indexed: 06/03/2023]
Abstract
Mercury (Hg) has been detected in polar bear brain tissue, but its biological effects are not well known. Relationships between Hg concentrations and neurochemical enzyme activities and receptor binding were assessed in the cerebellum, frontal lobes, and occipital lobes of 24 polar bears collected from Nunavik (Northern Quebec), Canada. The concentration-response relationship was further studied with in vitro experiments using pooled brain homogenate of 12 randomly chosen bears. In environmentally exposed brain samples, there was no correlative relationship between Hg concentration and cholinesterase (ChE) activity or muscarinic acetylcholine receptor (mAChR) binding in any of the 3 brain regions. Monoamine oxidase (MAO) activity in the occipital lobe showed a negative correlative relationship with total Hg concentration. In vitro experiments, however, demonstrated that Hg (mercuric chloride and methylmercury chloride) can inhibit ChE and MAO activities and muscarinic mAChR binding. These results show that Hg can alter neurobiochemical parameters but the current environmental Hg exposure level does have an effect on the neurochemistry of polar bears from northern Canada.
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Affiliation(s)
- Anke Krey
- Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, British Columbia, Canada
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16
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Lazarus M, Sekovanić A, Reljić S, Kusak J, Kovačić J, Orct T, Jurasović J, Huber Đ. Selenium in brown bears (Ursus arctos) from Croatia: Relation to cadmium and mercury. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2014; 49:1392-1401. [PMID: 25072771 DOI: 10.1080/10934529.2014.928497] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Muscle (n = 111), liver (n = 111), and kidney cortex (n = 101) samples from brown bears (Ursus arctos) were collected in the 2009 and 2010 hunting seasons in Croatia and analysed for selenium (Se), cadmium (Cd), and total mercury (Hg). The aim was to assess the levels of these elements according to age, sex, and season of collection, and to investigate possible Se/Cd and Se/Hg interactions. Median Se concentrations were 0.139 μg/g in muscle, 0.409 μg/g in liver and 1.75 μg/g wet mass in kidney cortex. Median Cd and Hg were 0.0078 and 0.0018 μg/g in muscle, 1.09 and 0.031 μg/g in liver, and 16.5 and 0.206 μg/g wet mass in the renal cortex, respectively. Se/Cd molar ratios were less than 1 in the kidney cortex, and close to or above 1 in liver and muscle, respectively. Toxic Cd and Hg correlated with Se in all of the studied tissues. Sex differences were found for all three elements (except Se in liver), with females having higher tissue concentration than males. Only Cd showed age-dependence. Bear samples collected in fall had higher Se in muscles, and Hg in muscles and liver compared to samples collected in spring. Element concentrations in brown bear tissues were within the range of previously reported studies. Bear meat is considered a rich source of Se, safe for consumption with regard to its Cd and Hg content. According to the molar ratio and correlation results, we assume that Se binding is not the primary detoxification pathway for Cd and Hg in brown bears.
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Affiliation(s)
- Maja Lazarus
- a Analytical Toxicology and Mineral Metabolism Unit, Institute for Medical Research and Occupational Health , Zagreb , Croatia
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17
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Ostertag SK, Stern GA, Wang F, Lemes M, Chan HM. Mercury distribution and speciation in different brain regions of beluga whales (Delphinapterus leucas). THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 456-457:278-286. [PMID: 23624002 DOI: 10.1016/j.scitotenv.2013.03.106] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 03/29/2013] [Accepted: 03/30/2013] [Indexed: 06/02/2023]
Abstract
The toxicokinetics of mercury (Hg) in key species of Arctic ecosystem are poorly understood. We sampled five brain regions (frontal lobe, temporal lobe, cerebellum, brain stem and spinal cord) from beluga whales (Delphinapterus leucas) harvested in 2006, 2008, and 2010 from the eastern Beaufort Sea, Canada, and measured total Hg (HgT) and total selenium (SeT) by inductively coupled plasma mass spectrometry (ICP-MS), mercury analyzer or cold vapor atomic absorption spectrometry, and the chemical forms using a high performance liquid chromatography ICP-MS. At least 14% of the beluga whales had HgT concentrations higher than the levels of observable adverse effect (6.0 mg kg(-1) wet weight (ww)) in primates. The concentrations of HgT differed between brain regions; median concentrations (mgkg(-1) ww) were 2.34 (0.06 to 22.6, 81) (range, n) in temporal lobe, 1.84 (0.12 to 21.9, 77) in frontal lobe, 1.84 (0.05 to 16.9, 83) in cerebellum, 1.25 (0.02 to 11.1, 77) in spinal cord and 1.32 (0.13 to 15.2, 39) in brain stem. Total Hg concentrations in the cerebellum increased with age (p<0.05). Between 35 and 45% of HgT was water-soluble, of which, 32 to 41% was methyl mercury (MeHg) and 59 to 68% was labile inorganic Hg. The concentration of MeHg (range: 0.03 to 1.05 mg kg(-1) ww) was positively associated with HgT concentration, and the percent MeHg (4 to 109%) decreased exponentially with increasing HgT concentration in the spinal cord, cerebellum, frontal lobe and temporal lobe. There was a positive association between SeT and HgT in all brain regions (p<0.05) suggesting that Se may play a role in the detoxification of Hg in the brain. The concentration of HgT in the cerebellum was significantly associated with HgT in other organs. Therefore, HgT concentrations in organs that are frequently sampled in bio-monitoring studies could be used to estimate HgT concentrations in the cerebellum, which is the target organ of MeHg toxicity.
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Affiliation(s)
- Sonja K Ostertag
- Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, British Columbia, V2N 4Z9, Canada.
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18
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Routti H, Letcher RJ, Born EW, Branigan M, Dietz R, Evans TJ, McKinney MA, Peacock E, Sonne C. Influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (Ursus maritimus). ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2012; 31:2739-2747. [PMID: 22987581 DOI: 10.1002/etc.2005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/13/2012] [Accepted: 07/01/2012] [Indexed: 06/01/2023]
Abstract
In the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (As, Cd, Cu, total Hg, Mn, Pb, Rb, Se, and Zn) concentrations measured in polar bears (Ursus maritimus) (n = 121) from 10 Alaskan, Canadian Arctic, and East Greenland subpopulations. Carbon and lipid sources were assessed using δ(13) C in muscle tissue and fatty acid (FA) profiles in subcutaneous adipose tissue as chemical tracers. A negative relationship between total Hg and δ(13) C suggested that polar bears feeding in areas with higher riverine inputs of terrestrial carbon accumulate more Hg than bears feeding in areas with lower freshwater input. Mercury concentrations were also positively related to the FA 20:1n-9, which is biosynthesized in large amounts in Calanus copepods. This result raises the hypothesis that Calanus glacialis are an important link in the uptake of Hg in the marine food web and ultimately in polar bears. Unadjusted total Hg, Se, and As concentrations showed greater geographical variation among polar bear subpopulations compared with concentrations adjusted for carbon and lipid sources. The Hg concentrations adjusted for carbon and lipid sources in Bering-Chukchi Sea polar bear liver tissue remained the lowest among subpopulations. Based on these findings, the authors suggest that carbon and lipid sources for polar bears should be taken into account when one is assessing spatial and temporal trends of long-range transported trace elements.
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Affiliation(s)
- Heli Routti
- Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment Canada, National Wildlife Research Centre, Carleton University, Ottawa, Ontario
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Kirk JL, Lehnherr I, Andersson M, Braune BM, Chan L, Dastoor AP, Durnford D, Gleason AL, Loseto LL, Steffen A, St Louis VL. Mercury in Arctic marine ecosystems: sources, pathways and exposure. ENVIRONMENTAL RESEARCH 2012; 119:64-87. [PMID: 23102902 PMCID: PMC4142812 DOI: 10.1016/j.envres.2012.08.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 08/02/2012] [Accepted: 08/13/2012] [Indexed: 05/20/2023]
Abstract
Mercury in the Arctic is an important environmental and human health issue. The reliance of Northern Peoples on traditional foods, such as marine mammals, for subsistence means that they are particularly at risk from mercury exposure. The cycling of mercury in Arctic marine systems is reviewed here, with emphasis placed on the key sources, pathways and processes which regulate mercury levels in marine food webs and ultimately the exposure of human populations to this contaminant. While many knowledge gaps exist limiting our ability to make strong conclusions, it appears that the long-range transport of mercury from Asian emissions is an important source of atmospheric Hg to the Arctic and that mercury methylation resulting in monomethylmercury production (an organic form of mercury which is both toxic and bioaccumulated) in Arctic marine waters is the principal source of mercury incorporated into food webs. Mercury concentrations in biological organisms have increased since the onset of the industrial age and are controlled by a combination of abiotic factors (e.g., monomethylmercury supply), food web dynamics and structure, and animal behavior (e.g., habitat selection and feeding behavior). Finally, although some Northern Peoples have high mercury concentrations of mercury in their blood and hair, harvesting and consuming traditional foods have many nutritional, social, cultural and physical health benefits which must be considered in risk management and communication.
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Affiliation(s)
- Jane L Kirk
- Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Dr, Burlington, ON L7R 4A6, Canada.
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20
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Krey A, Kwan M, Chan HM. Mercury speciation in brain tissue of polar bears (Ursus maritimus) from the Canadian Arctic. ENVIRONMENTAL RESEARCH 2012; 114:24-30. [PMID: 22406289 DOI: 10.1016/j.envres.2012.01.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2011] [Revised: 01/03/2012] [Accepted: 01/31/2012] [Indexed: 05/31/2023]
Abstract
Methylmercury (MeHg) is a neurotoxicant that has been found at elevated concentrations in the Arctic ecosystem. Little is known about its internal dose in wildlife such as polar bears. We measured concentrations of mercury (Hg) in three different brain regions (cerebellum, frontal lobe and brain stem) of 24 polar bears collected from the Nunavik, Canada between 2000 and 2003. Speciation of Hg was measured by High Performance Liquid Chromatography coupled to Inductively Coupled Plasma Mass Spectroscopy (HPLC-ICP-MS). Concentrations of mean total Hg in brain tissue were up to 625 times lower (0.28 ± 0.07 mg kg(-1) dry weight (dw) in frontal lobe, 0.23 ± 0.07 mg kg(-1) dw in cerebellum and 0.12 ± 0.0 3mg kg(-1) dw in brain stem) than the mean total Hg concentration previously reported in polar bear liver collected from Eastern Baffin Island. Methylmercury (MeHg) accounted for 100% of the Hg found in all three brain regions analyzed. These results suggest that polar bear might reduce the toxic effects of Hg by limiting the uptake into the brain and/or decrease the rate of demethylation so that Hg can be excreted from the brain more easily. The toxicokinetics and the blood-brain-barrier mechanisms of polar bears are still unknown and further research is required.
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Affiliation(s)
- Anke Krey
- Natural Resources and Environmental Studies, University of Northern British Columbia, Prince George, BC, Canada
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21
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Aubail A, Dietz R, Rigét F, Sonne C, Wiig Ø, Caurant F. Temporal trend of mercury in polar bears (Ursus maritimus) from Svalbard using teeth as a biomonitoring tissue. ACTA ACUST UNITED AC 2012; 14:56-63. [DOI: 10.1039/c1em10681c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Pilarczyk B, Drozd R, Pilarczyk R, Tomza-Marciniak A, Jankowiak D, Hendzel D, Kuba J, Kowalska J. Glutathione peroxidase (GSHPx) activity in the liver of red deer in relation to hepatic selenium concentrations, sex, body weight and season of the year. Biol Trace Elem Res 2011; 144:560-9. [PMID: 21416340 DOI: 10.1007/s12011-011-9022-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 03/02/2011] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to determine glutathione peroxidase (GSHPx) activity in the liver of red deer in relation to selenium concentrations in the liver, as well as to evaluate changes in GSHPx activity according to sex, body weight and season of the year. Total selenium concentration in the liver of red deer averaged 0.095 ± 0.018 μg/g of wet weight. GSHPx activity in the liver of red deer ranged widely from 4.4 to 45.8 U/g of protein. Females were characterized by higher GSHPx activity compared to males (21.2 vs. 17.0 U/g protein). The highest GSHPx activity was recorded in autumn and the lowest in summer. The lowest GSHPx activity in the liver was found in the heaviest animals (>100 kg body weight), averaging 14.0 U/g protein. Animals weighing <66 kg and 66-100 kg were characterized by similar activity of 25.1 and 24.5 U/g, respectively. Despite the differences in GSHPx activity according to sex, body weight and season of the year, these factors had no significant effect on the activity of this enzyme. The main factor regulating GSHPx activity in the liver of examined red deer was selenium concentration.
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Affiliation(s)
- Bogumiła Pilarczyk
- Department of Animal Reproduction Biotechnology and Environmental Hygiene, West Pomeranian University of Technology in Szczecin, Judyma 6 Street, 71-466, Szczecin, Poland.
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Rigét F, Braune B, Bignert A, Wilson S, Aars J, Born E, Dam M, Dietz R, Evans M, Evans T, Gamberg M, Gantner N, Green N, Gunnlaugsdóttir H, Kannan K, Letcher R, Muir D, Roach P, Sonne C, Stern G, Wiig O. Temporal trends of Hg in Arctic biota, an update. THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 409:3520-6. [PMID: 21684574 DOI: 10.1016/j.scitotenv.2011.05.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 04/27/2011] [Accepted: 05/03/2011] [Indexed: 05/26/2023]
Abstract
A statistically robust method was applied to 83 time-series of mercury in Arctic biota from marine, freshwater and terrestrial ecosystems with the purpose of generating a 'meta-analysis' of temporal trend data collected over the past two to three decades, mostly under the auspices of the Arctic Monitoring and Assessment Program (AMAP). Sampling locations ranged from Alaska in the west to northern Scandinavia in the east. Information from recently published temporal trend studies was tabulated to supplement the results of the statistical analyses. No generally consistent trend was evident across tissues and species from the circumpolar Arctic during the last 30years or so. However, there was a clear west-to-east gradient in the occurrence of recent increasing Hg trends, with larger numbers and a higher proportion of biotic datasets in the Canadian and Greenland region of the Arctic showing significant increases than in the North Atlantic Arctic. Most of the increasing datasets were for marine species, especially marine mammals. A total of 16 (19%) out of the 83 time-series could be classified as "adequate", where adequate is defined as the number of actual monitoring years in a time-series being equal to or greater than the number of years of sampling required to detect a 5% annual change in Hg concentrations, with a significance level of P<0.05 and 80% statistical power. At the time of the previous AMAP Assessment, only 10% of the Hg time-series were deemed adequate. If an additional 5years of data were to be added to the current set of time-series, it is predicted that 53% of time-series would become adequate.
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Affiliation(s)
- Frank Rigét
- National Environmental Research Institute (NERI), Aarhus University (AAU), Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark.
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St Louis VL, Derocher AE, Stirling I, Graydon JA, Lee C, Jocksch E, Richardson E, Ghorpade S, Kwan AK, Kirk JL, Lehnherr I, Swanson HK. Differences in mercury bioaccumulation between polar bears (Ursus maritimus) from the Canadian high- and sub-Arctic. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:5922-5928. [PMID: 21678897 DOI: 10.1021/es2000672] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Polar bears (Ursus maritimus) are being impacted by climate change and increased exposure to pollutants throughout their northern circumpolar range. In this study, we quantified concentrations of total mercury (THg) in the hair of polar bears from Canadian high- (southern Beaufort Sea, SBS) and sub- (western Hudson Bay, WHB) Arctic populations. Concentrations of THg in polar bears from the SBS population (14.8 ± 6.6 μg g(-1)) were significantly higher than in polar bears from WHB (4.1 ± 1.0 μg g(-1)). On the basis of δ(15)N signatures in hair, in conjunction with published δ(15)N signatures in particulate organic matter and sediments, we estimated that the pelagic and benthic food webs in the SBS are ∼ 4.7 and ∼ 4.0 trophic levels long, whereas in WHB they are only ∼ 3.6 and ∼ 3.3 trophic levels long. Furthermore, the more depleted δ(13)C ratios in hair from SBS polar bears relative to those from WHB suggests that SBS polar bears feed on food webs that are relatively more pelagic (and longer), whereas polar bears from WHB feed on those that are relatively more benthic (and shorter). Food web length and structure accounted for ∼ 67% of the variation we found in THg concentrations among all polar bears across both populations. The regional difference in polar bear hair THg concentrations was also likely due to regional differences in water-column concentrations of methyl Hg (the toxic form of Hg that biomagnifies through food webs) available for bioaccumulation at the base of the food webs. For example, concentrations of methylated Hg at mid-depths in the marine water column of the northern Canadian Arctic Archipelago were 79.8 ± 37.3 pg L(-1), whereas, in HB, they averaged only 38.3 ± 16.6 pg L(-1). We conclude that a longer food web and higher pelagic concentrations of methylated Hg available to initiate bioaccumulation in the BS resulted in higher concentrations of THg in polar bears from the SBS region compared to those inhabiting the western coast of HB.
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Affiliation(s)
- Vincent L St Louis
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Routti H, Letcher RJ, Born EW, Branigan M, Dietz R, Evans TJ, Fisk AT, Peacock E, Sonne C. Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland. ACTA ACUST UNITED AC 2011; 13:2260-7. [DOI: 10.1039/c1em10088b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Liver and kidney concentrations of selenium in wild boars (Sus scrofa) from northwestern Poland. EUR J WILDLIFE RES 2010. [DOI: 10.1007/s10344-010-0380-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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RICHARD PILSNER J, LAZARUS ALICIAL, NAM DONGHA, LETCHER ROBERTJ, SONNE CHRISTIAN, DIETZ RUNE, BASU NILADRI. Mercury-associated DNA hypomethylation in polar bear brains via the LUminometric Methylation Assay: a sensitive method to study epigenetics in wildlife. Mol Ecol 2009; 19:307-14. [DOI: 10.1111/j.1365-294x.2009.04452.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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