European roe deer antlers as an environmental archive for fallout 236U and 239PU

Anthropogenic U-236 and Pu-239 were measured in European roe deer antlers hunted between 1955 and 1977 which covers and extends beyond the period of intensive nuclear weapons testing (1954-1962). The antlers were hunting trophies, and hence the hunting area, the year of shooting and the approximate age of each animal is given. Uranium and plutonium are known to deposit in skeletal tissue. Since antler histology is similar to bone, both elements were expected in antlers. Furthermore, roe deer shed their antlers annually, and hence antlers may provide a time-resolved environmental archive for fallout radionuclides. The radiochemical procedure is based on a Pu separation step by anion exchange (Dowex 1 x 8) and a subsequent U purification by extraction chromatography using UTEVA((R)). The samples were measured by Accelerator Mass Spectrometry at the VERA facility (University of Vienna). In addition to the U-236 and Pu-239 concentrations, the Pu-240/Pu-239 isotopic ratios were determined with a mean value of 0.172 +/- 0.023 which is in agreement with the ratio of global fallout (similar to 0.18). Rather high U-236/U-238 ratios of the order of 10(-6) were observed. These measured ratios, where the U-236 arises only from global fallout, have implications for the use of the U-236/U-238 ratio as a fingerprint for nuclear accidents or releases from nuclear facilities. Our investigations have shown the potential to use antlers as a temporally resolved archive for the uptake of actinides from the environment. (C) 2015 Elsevier Ltd. All rights reserved.