Mercury Levels and Health in East Greenland Polar Bears
Author Information
Author(s): Christian Sonne, Rune Dietz, Pall S. Leifsson, Asmund Gert, Erik W. Born, Maja Kirkegaard
Primary Institution: National Environmental Research Institute, University of Aarhus
Hypothesis
Are liver and renal lesions in East Greenland polar bears associated with high mercury levels?
Conclusion
The study found that while liver and kidney lesions in polar bears were likely due to age and infections, long-term mercury exposure could not be ruled out as a contributing factor.
Supporting Evidence
- Liver mercury levels ranged from 1.1–35.6 μg/g wet weight.
- Renal mercury levels ranged from 1–50 μg/g wet weight.
- 2 liver values and 9 kidney values were above the known toxic threshold level of 30 μg/g wet weight.
- Liver mercury levels were significantly higher in individuals with visible Ito cells (p < 0.02).
- Liver mercury levels were significantly lower in individuals with portal bile duct proliferation/fibrosis (p = 0.007).
Takeaway
Scientists looked at polar bears in Greenland to see if their health problems were caused by mercury. They found that while age and infections were big reasons for the problems, mercury might also play a role.
Methodology
The study analyzed liver and kidney tissues from polar bears for histopathological changes and mercury levels using statistical analyses.
Potential Biases
Potential biases may arise from the sampling method and the reliance on local hunters for tissue collection.
Limitations
The study could not definitively establish a causal relationship between mercury levels and health issues due to confounding factors like age and infections.
Participant Demographics
The sample included 32 subadult bears (10 females and 22 males), 15 adult females, and 12 adult males.
Statistical Information
P-Value
p < 0.02 for significant findings
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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