Intercomparison exercise for the determination of 241Am in the human skeleton

241Am is known to be a bone-seeking isotope. In the long term it enters the human skeleton. In this paper, the case of a now 62 year old male subject who incorporated 241Am in the early seventies, is used in order to compare state-of-the-art techniques for the detection of 241Am in the human skeleton. The individual was measured using either partial (4 laboratories) or whole-body counters (1 laboratory). The results of each laboratory are discussed separately. The skull measurements, performed by four laboratories, are in good agreement when using the same skull calibration phantom. Based on these results, the estimated total skeleton activity is in reasonable agreement with the result of a whole-body measurement performed by the fifth laboratory. A preliminary 241Am skeleton burden of about 3.5 kBq is estimated for 1996. (author)