Hair as an indicator of the body content of polonium in humans: preliminary results from study of five male volunteers

摘要

The radionuclide Po-210 is of importance from a radiation protection view and has properties that cause special problems when attempting to determine the body content in humans. Estimates have traditionally been made from either urine and/or fecal samples, which require a time-consuming radiochemical preparation before alpha spectrometric determination. In order to find a more simple and less labor intensive method hair has been used as a bioindicator and investigated in this study. The relationship between intake and excretion in hair has been estimated in five volunteers who ingested radioactive polonium (Po-209 as a bio-tracer for Po-210) in well determined quantities. Four of the volunteers were given 5-10 Bq Po-209 in a single intake (acute intake) and one volunteer has ingested a daily intake of 58.7 mBq Po-209 for a period of 180 d. Human hair was found to reflect the daily clearance of ingested polonium peaking at 0.001-0.01% d(-1) of the ingested amount, thereafter decreasing monoexponentially, corresponding to a biological half-time of 10-20 days. For the case of protracted intake a mono-exponential build-up was observed with a half-time of 40 +/- 5 d. In addition, after cessation of intake, a short-term component (74%) with a biological half-time of 16 +/- 4 d, and a long-term component (26%) with a half-time of 93 +/- 53 d were observed. It is concluded that hair can be used to detect not only the amount of ingested polonium but also whether the intake was protracted or acute. (C) 2014 Elsevier Ltd. All rights reserved.