Plutonium and other alpha-emitters in bones of wild, herbivorous animals from north-eastern Poland

The results of the investigation of Pu239+240, Am-241 and thorium isotope a ctivity concentrations in bones of wild herbivorous animals (deer, roe-deer , boars, elks) from north-eastern Poland are presented. The area on which t he animals were living had relatively high Chernobyl plutonium fallout. Pos sible traces of plutonium were seen only in four samples, but only for one it was it 3 sigma above background, at 6.2 +/- 2.4 mBq/kg (ash). The Am-241 activity concentration was below the detection limits in all samples. The maximum Th-228 concentration in the samples was 7.81 +/- 0.44 Bq/kg (ash), calculated under the assumption of 100% thorium recovery. This isotope seem s to originate in bones not from direct incorporation but from the decay of Ra-228. Large variations in activity concentration wose observed, as well as some differences between boars and the chewing animals. (C) 2000 Elsevie r Science Ltd. All rights reserved.