ABSTRACT
This study aimed at assessing the incorporation of radionuclides in animals in the proximity of the uranium mine in Caetité, Brazil. In 2014, samples of bovine and equine teeth and skull bones were collected and their contents of natural and artificial isotopes were assessed using nuclear spectrometry techniques. Gamma ray emission from 226,228Ra and 40K isotopes was determined using high-purity germanium (HPGe) spectrometry, 90Sr radioactivity was measured with liquid scintillation, and 234,238U, 232,230,228Th, 210Po and 239+240Pu radioactivity was assessed with alpha-spectrometry. Prior to the measurements, sample dissolutions and isotope separations were performed. Our results indicate a high 228Th isotope content in the skull bones and the teeth of animals, up to 179 Bq per kg of ash. The 226Ra and 228Ra concentrations were slightly lower. Activity concentrations of other isotopes were significantly lower or below the detection limit. We could not identify sources of technologically enhanced levels of 228Ra in the area we investigated; therefore we suggest that their origin is natural.