Red Fox Vulpes vulpes (L., 1758) as a Bioindicator of Mercury Contamination in Terrestrial Ecosystems of North-Western Poland

In this study, we determined the concentrations of total mercury (Hg) in samples of liver, kidney and skeletal muscle of 27 red foxes Vulpes vulpes (L., 1758) from north-western Poland, and examined the morphometric characteristics of the collected specimens. The analysis also included the relationship between Hg concentration and the fox size, and the suitability of individual organs as bioindicators in indirect evaluation of environmental mercury contamination. Determination of Hg concentration was performed by atomic absorption spectroscopy. In the analysed samples, the Hg concentration was low and the maximum value did not exceed 0.85 mgHg/kg dry weight (dw). There were no significant differences in Hg concentrations in the analysed material between males and females or between immature and adult groups. The median concentrations of Hg in the liver, kidney and skeletal muscle were 0.22, 0.11 and 0.05 mgHg/kg dw, respectively. The correlation coefficients were significant between the concentrations of mercury in the liver, kidney and skeletal muscle (positive) and between the kidney Hg concentration and kidney mass (negative). Taking into account our results and findings of other authors, it may be argued that the red fox exhibits a measurable response to mercury environmental pollution and meets the requirements of a bioindicator

Fluoride in the Bones of Foxes (Vulpes vulpes Linneaus, 1758) and Raccoon Dogs (Nyctereutes procyonoides Gray, 1834) from North-Western Poland

Assessment of exposure to fluoride (F(−)) is increasingly focused on mineralized tissues, mainly bones. Their periodic growth and continuous reconstruction make them a good material for studying long-term F(−) accumulation. In this study, F(−)concentrations were determined in the bones of foxes and raccoon dogs from north-western Poland and relationships between bone F(−) and the age categories of the animals were attempted to be identified. Bone samples were collected from femurs of 32 foxes (15 males and 17 females) and 18 raccoon dogs (10 males and 8 females) from polluted, medium-polluted, and unpolluted by F(−) areas. Bone F(−) was determined by potentiometric method, and results were expressed per dry weight (dw); they ranged from 176 to 3,668 mg/kg dw in foxes and from 84 to 1,190 mg/kg dw in raccoon dogs. Foxes from north-western Poland accumulated much more F(−) in their bones than raccoon dogs. Our study shows that the assessment of hazards created by industrial emitters can be conducted conveniently by the measurements of fluorine content in hard tissues of wild animals. Due to availability of such type of material for studies, it seems that the analysis of fluoride content in bones can be a good tool in the development of ecotoxicology