Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels?
Abstract Background In the Arctic, polar bears ( Ursus maritimus ) bio-accumulate mercury as they prey on polluted ringed seals ( Phoca hispida ) and bearded seals ( Erignathus barbatus ). Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arct...
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BioMed Central Ltd.
2007
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ftbiomed:oai:biomedcentral.com:1476-069X-6-11 2023-05-15T14:52:00+02:00 Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? Sonne, Christian Dietz, Rune Leifsson, Pall S Asmund, Gert Born, Erik W Kirkegaard, Maja 2007-04-17 http://www.ehjournal.net/content/6/1/11 en eng BioMed Central Ltd. http://www.ehjournal.net/content/6/1/11 Copyright 2007 Sonne et al; licensee BioMed Central Ltd. Research 2007 ftbiomed 2007-11-11T15:25:46Z Abstract Background In the Arctic, polar bears ( Ursus maritimus ) bio-accumulate mercury as they prey on polluted ringed seals ( Phoca hispida ) and bearded seals ( Erignathus barbatus ). Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. Methods We investigated the histopathological impact from anthropogenic long-range transported mercury on East Greenland polar bear liver (n = 59) and kidney (n = 57) tissues. Results Liver mercury levels ranged from 1.1–35.6 μg/g wet weight and renal levels ranged from 1–50 μg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 μg/g wet weight in terrestrial mammals. Evaluated from age-correcting ANCOVA analyses, liver mercury levels were significantly higher in individuals with visible Ito cells (p < 0.02) and a similar trend was found for lipid granulomas (p = 0.07). Liver mercury levels were significantly lower in individuals with portal bile duct proliferation/fibrosis (p = 0.007) and a similar trend was found for proximal convoluted tubular hyalinisation in renal tissue (p = 0.07). Conclusion Based on these relationships and the nature of the chronic inflammation we conclude that the lesions were likely a result of recurrent infections and ageing but that long-term exposure to mercury could not be excluded as a co-factor. The information is important as it is likely that tropospheric mercury depletion events will continue to increase the concentrations of this toxic heavy metal in the Sub Arctic and Arctic marine food webs. Other/Unknown Material Arctic East Greenland Erignathus barbatus Greenland Phoca hispida Ursus maritimus BioMed Central Arctic Greenland |
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BioMed Central |
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ftbiomed |
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English |
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Abstract Background In the Arctic, polar bears ( Ursus maritimus ) bio-accumulate mercury as they prey on polluted ringed seals ( Phoca hispida ) and bearded seals ( Erignathus barbatus ). Studies have shown that polar bears from East Greenland are among the most mercury polluted species in the Arctic. It is unknown whether these levels are toxic to liver and kidney tissue. Methods We investigated the histopathological impact from anthropogenic long-range transported mercury on East Greenland polar bear liver (n = 59) and kidney (n = 57) tissues. Results Liver mercury levels ranged from 1.1–35.6 μg/g wet weight and renal levels ranged from 1–50 μg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 μg/g wet weight in terrestrial mammals. Evaluated from age-correcting ANCOVA analyses, liver mercury levels were significantly higher in individuals with visible Ito cells (p < 0.02) and a similar trend was found for lipid granulomas (p = 0.07). Liver mercury levels were significantly lower in individuals with portal bile duct proliferation/fibrosis (p = 0.007) and a similar trend was found for proximal convoluted tubular hyalinisation in renal tissue (p = 0.07). Conclusion Based on these relationships and the nature of the chronic inflammation we conclude that the lesions were likely a result of recurrent infections and ageing but that long-term exposure to mercury could not be excluded as a co-factor. The information is important as it is likely that tropospheric mercury depletion events will continue to increase the concentrations of this toxic heavy metal in the Sub Arctic and Arctic marine food webs. |
format |
Other/Unknown Material |
author |
Sonne, Christian Dietz, Rune Leifsson, Pall S Asmund, Gert Born, Erik W Kirkegaard, Maja |
spellingShingle |
Sonne, Christian Dietz, Rune Leifsson, Pall S Asmund, Gert Born, Erik W Kirkegaard, Maja Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
author_facet |
Sonne, Christian Dietz, Rune Leifsson, Pall S Asmund, Gert Born, Erik W Kirkegaard, Maja |
author_sort |
Sonne, Christian |
title |
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
title_short |
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
title_full |
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
title_fullStr |
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
title_full_unstemmed |
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels? |
title_sort |
are liver and renal lesions in east greenland polar bears (ursus maritimus) associated with high mercury levels? |
publisher |
BioMed Central Ltd. |
publishDate |
2007 |
url |
http://www.ehjournal.net/content/6/1/11 |
geographic |
Arctic Greenland |
geographic_facet |
Arctic Greenland |
genre |
Arctic East Greenland Erignathus barbatus Greenland Phoca hispida Ursus maritimus |
genre_facet |
Arctic East Greenland Erignathus barbatus Greenland Phoca hispida Ursus maritimus |
op_relation |
http://www.ehjournal.net/content/6/1/11 |
op_rights |
Copyright 2007 Sonne et al; licensee BioMed Central Ltd. |
_version_ |
1766323134085988352 |