Natural α-Radioactivity Concentrations in Bone and Liver from Various Animal Species

Abstract

THE radiation dose received by man as a result of exposure to naturally occurring nuclear radiation has been investigated thoroughly in recent years, and critical summaries of the data are available^1–4. The natural radiation dose received by other animal species has received less attention. The principal source of interspecies variation in the dose is likely to be the contribution from internally deposited alpha-emitting nuclides⁵. Mayneord⁶ has referred to this “almost untouched field of research”, and he and his co-workers^7,8 have tabulated total alpha-activities in bone ash from about a dozen different animal species. Although data on specific isotopes in certain species have been reported^9–16, there is to our knowledge no other comparative interspecies study. We report here the preliminary results of a similar but more extensive study. The data have been obtained using the total alpha-counting technique developed by Turner et al.¹⁷ and used previously in this laboratory^18–21. We have prepared our samples for counting by cleaning, steaming, drying and grinding (bones) or by freeze-drying and grinding (soft tissues).