Transfer of plutonium, americium and curium from fallout into reindeer after the Chernobyl accident

Several reindeer tissue samples were analysed for transuranium elements following the Chernobyl accident in 1986. Pu, Am and Cm were separated using coprecipitation and anion exchange steps, and measured with alpha spectrometry. The activity concentrations of 239,240Pu in reindeer liver found in this study (0.0094–0.062 Bq kg–1 d.w. [= dry weight]) are low compared to the concentrations found in the 1960s and 1970s, even though most of the samples are from the areas with the heaviest Chernobyl-derived fallout of plutonium. On the other hand, the 241Pu concentrations in reindeer liver found in this study (0.7–3.9 Bq kg–1 d.w.) are comparable to earlier results. The calculated transfer factors, (0.31–1.61) x 10–5 m2 kg–1 for 239,240Pu and 7 x 10–3 m2 kg–1 for 241Am, show that 137Cs migrates from fallout to reindeer meat 100 times more efficiently than 241Am and 10000 times more efficiently than 239,240Pu. The transfer factor of 2 x 10–3 m2 kg–1 obtained for 242Cm does not take into account the physical decay of 242Cm. Several earlier results concerning plutonium and americium in reindeer could be verified in this study using the fallout from the Chernobyl accident. Americium and curium are accumulated more efficiently than plutonium in bone and lungs. The main pathway of Pu, Am and Cm into reindeer is the gastro-intestinal (GI) tract and not inhalation. The absorption coefficient of 239,240Pu obtained for the GI-tract, 3.0 x 10–5, is in agreement with earlier results. A GI-tract absorption coefficient of 7.5 x 10–4 for 241Am was obtained in this study.