23 research outputs found
Are liver and renal lesions in East Greenland polar bears (Ursus maritimus) associated with high mercury levels?
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 1.1â35.6 ÎŒg/g wet weight and renal levels ranged from 1â50 ÎŒg/g wet weight, of which 2 liver values and 9 kidney values were above known toxic threshold level of 30 ÎŒg/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
Success factors and future prospects of PontoâCaspian peracarid (Crustacea: Malacostraca) invasions: Is âthe worst overâ?
Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients
The embryoid development of Strigamia maritimaand its bearing on post-embryonic segmentation of geophilomorph centipedes
Pfesiomorphie and apomorphic characters states in the class Chilopoda
Volume: 169Start Page: 299End Page: 30
Preliminary data on the anatomy of the genital systems In Craterostigmus tosmanianus (Craterostigmomorpha) and Esastigmatobius longitarsis (Henicopidae, Lithobiomorpha) (Chilopoda)
Volume: 169Start Page: 341End Page: 34