Concentration of heavy metals in hair and skin of silver and red foxes (Vulpes vulpes)

The structure of hair and levels of main chemical elements (C, N, O, S, Cl, Ca, P, Al, Na) in the external layer of hair of silver and red foxes (Vulpes vulpes) in a non-industrialised, typically agricultural region of middle-west Poland was assessed using a scanning microscope. Additionally, analysis of the accumulation of certain heavy metals (Cr, Cu, Ni, Pb and Zn) in hair (washed) and skin (non-tanned) of those foxes was conducted. Heavy metal levels were determined using a spectrophotometric method (ICP-OES), and correlations between these levels in hair and skin were calculated. The microscopic external (morphological) and internal structures (histological) of the hair of farm and wild foxes were not differentiated; however, the hair of farm foxes (external layer) contained higher amounts of C, Na, Al and P. A significantly higher Pb content was noted in non-tanned skin of wild foxes in comparison to farm ones. In the case of farm foxes, a significantly higher Zn content in hair and Zn and Cu in skin was observed in comparison to wild ones. Positive significant correlations between Cr and Ni content (r = 0.622) and Zn and Cu (r = 0.721) in fox skin were noted. A similar relationship between Cr content in hair and Ni in skin (r = 0.643) and between Zn in hair and skin (r = 0.595) was also observed.