RESUMEN
The aim of the present study was to investigate the relationships and effects of oral POP exposure on retinol (vitamin A), α-tocopherol (vitamin E), thyroid hormones and testosterone in emaciated adult farmed Arctic foxes. Eight brother-pairs were exposed to either a diet containing naturally POP-contaminated minke whale blubber (Balaenoptera acutorostrata) (n=8), or a control diet containing pig (Sus scrofa) fat as the primary fat source (n=8) for 22 months. In the whale blubber containing feed the ∑POPs concentration was 802ng/g w.w. and it was 24ng/g w.w. in control feed. The liver mass was significantly higher and the ratio of FT4 (free thyroxine):FT3 (free triiodothyronine) was significantly lower in the POP exposed group as compared to the control group given feed with pig fat (both p<0.05). The exposed group revealed lower plasma and liver concentrations of α-tocopherol compared to the control group (both p<0.05). These results indicate that plasma FT4:FT3 ratio and plasma and liver α-tocopherol are valuable biomarker endpoints for chronic oral POP exposure in wild Arctic foxes. Based on this we suggest that plasma FT4:FT3 ratio and plasma and liver α-tocopherol are valuable biomarker endpoints for chronic POP exposure in wildlife Arctic foxes and that these perturbations may affect their health status.