Polonium-210 and Caesium-137 in lynx (Lynx lynx), wolverine (Gulo gulo) and wolves (Canis lupus)

Wolves, lynx and wolverines are on the top of the food-chain in northern Scandinavia and Finland. ²¹⁰Po and ¹³⁷Cs have been analysed in samples of liver, kidney and muscle from 28 wolves from Sweden. In addition blood samples were taken from 27 wolves. In 9 of the wolves, samples of muscle, liver and blood were analysed for ²¹⁰Po. Samples of liver and muscle were collected from 16 lynx and 16 wolverines from Norway. The liver samples were analysed for ²¹⁰Po and ¹³⁷Cs. Only ¹³⁷Cs analyses were carried out for the muscle samples. The wolves were collected during the winter 2010 and 2011, while the samples for lynx and wolverines were all from 2011. The activity concentrations of ²¹⁰Po in wolves were higher for liver (range 20–523 Bq kg⁻¹ d.w.) and kidney (range 24–942 Bq kg⁻¹ d.w.) than muscle (range 1–43 Bq kg⁻¹ d.w.) and blood (range 2–54 Bq kg⁻¹ d.w.). Activity ratios, ²¹⁰Po/²¹⁰Pb, in wolf samples of muscle, liver and blood were in the ranges 2–77, 9–56 and 2–54. Using a wet weight ratio of 3.8 the maximal absorbed dose from ²¹⁰Po to wolf liver was estimated to 3500 μGy per year. Compared to wolf, the ranges of ²¹⁰Po in liver samples were lower in lynx (range 22–211 Bq kg⁻¹ d.w.) and wolverine (range16–160 Bq kg⁻¹ d.w.). Concentration of ¹³⁷Cs in wolf samples of muscle, liver, kidney and blood were in the ranges 70–8410 Bq kg⁻¹ d.w., 36–4050 Bq kg⁻¹ d.w., 31–3453 Bq kg⁻¹ d.w. and 4–959 Bq kg⁻¹ d.w., respectively. ¹³⁷Cs in lynx muscle and liver samples were in the ranges 44–13393 Bq kg⁻¹ d.w. and 125–10260 Bq kg⁻¹ d.w. The corresponding values for ¹³⁷Cs in wolverine were 22–3405 Bq kg⁻¹ d.w. for liver and 53–4780 Bq kg⁻¹ d.w. for muscle. The maximal absorbed dose from ¹³⁷Cs to lynx was estimated to 3000 μGy per year. - Highlights: • Annual doses from ²¹⁰Po are 1.4, 1.0 and 3.4 mGy for lynx, wolverine, and wolf. • Annual doses from ¹³⁷Cs are 3.3, 1.5 and 3.6 mGy for lynx, wolverine and wolf. • ²¹⁰Po/¹³⁷Cs ratios in wolf liver ranges from 0.01 to 4.0 and 0.002 to 0.05 in muscle. • The large spread in the data is due to the distribution of ¹³⁷Cs from Chernobyl. • The accumulation of ²¹⁰Po in liver and kidney is higher than for ¹³⁷Cs