Technetium in the Environment

ISBN-13: 9789401083614 / Angielski / Miękka / 2011 / 436 str.

G. Desmet; C. Myttenaere

Opis

Since the discovery of technetium (in 1937, by Perrier and Segre), technetium-99 and technetium-99m have become most familiar in the specialised literature, the behaviour of the former being of concern regarding its health impact, the latter having been used intensively in medical tests for many years. The knowledge of the characteristics and behaviour of this element in nature is currently increasing exponentially. It has become clear, however, that there is still a serious shortage of information needed to assess properly its burden and impact on man and his environment. Technetium may indeed be released from nuclear installations or as a waste product from medical applications. It is generally considered to be highly mobile as the anion TcOi, but it is also suspected to be readily reduced in soils and metabolised in living beings into lower oxidation states. The seminar was planned to analyse thoroughly the experimental results obtained up to now and to make recommendations of specific issues requiring further research. This book presents the papers of the different sessions in the order of presentation, and the conclusions drawn by three discussion groups which dealt separately with: problems of sources and distribution of man-made technetium and its radiological consequences; the chemical behaviour of technetium in different ecosystems; biochemical reactions and binding with macromolecules in various life systems. vi Preface The editors, together with the Programme Committee of the Seminar, wish to express their gratitude to the chairmen of the different sessions for their summary of the group discussions.

Spis treści

1. Source Terms for Technetium-99 from Nuclear Fuel Cycle Facilities.- 2. Technetium Discharges into the Environment.- 3. Radiochemical Determination of Tc-99 and Release of Tc-99 from Nuclear Facilities.- 4. Activités du Technétium 99 Mesurées dans les Eaux Résiduaires, l’Eau de Mer et Deux Bioindicateurs (Littoral de la Manche, 1983).- 5. Teehnetium-99 in Algae from Temperate and Arctic Waters of the North Atlantic.- 6. Technetium-99 in the Baltic Sea.- 7. Time Trend of 99Tc in Seaweed from Greenland Waters...- 8. Behaviour of Technetium in Freshwater Environments.- 9. Role of Organic Matter as a Geochemical Sink for Technetium in Soils and Sediments.- 10. Technetium Sorption in Surface Soils.- 11. Technetium Behaviour in Soils of the Canadian Preeambrian Shield.- 12. Soil—Humic Acid Complexes of Technetium: Synthesis and Characterisation.- 13. Measurement of the Complexation Capacity of Organic Matter in Dilute Extracts of Soils and Sediments.- 14. 99Tc in Environmental Waters.- 15. Properties and Solubility of Technetium Dioxide.- 16. Relevance of the Study of Technetium Accumulation and Speciation in Plants.- 17. A Review of the Biological and Geochemical Behaviour of Technetium in the Marine Environment.- 18. Accumulation and Loss of Technetium by Macrophytic Algae.- 19. Technetium in Micro-organisms.- 20. Technetium in Marine Animals.- 21. Le Technétium et l’Ormeau (Haliotis tuberculata): Données Expérimentales et ‘in situ’.- 22. Plant Root Absorption and Metabolic Fate of Technetium in Plants.- 23. Processus Biologiques Responsables de l’Accumulation du Tc-99 par les Végétaux.- 24. Accumulation of Tc—Bio-organic Complexes in Spinach Plants in Relation to Growth.- 25. Speciation of Technetium in Plants Grown on Substrates which Contained Different Chemical Forms of Technetium.- 26. Rétention par les Végétaux du Technétium Relaché dans l’Environnement en Association avec d’Autres Radiopolluants.- 27. Chemical Form of Technetium in Corn (Zea mays) and the Gastrointestinal Absorption of Plant-incorporated Tc by Laboratory Rats.- 28. Absorption and Retention in Sheep of Technetium Administered into the Rumen as Pertechnetate or Bound to Food.- 29. Transfer of 131I and 95mTc from Pasture to Goat Milk.- 30. Distribution of Orally Administered and Chronically Fed 95mTc in Japanese Quail Tissues and Eggs.- 31. The Significance of Environmental Exposure Pathways for Technetium.- 32. Estimations des Risques Radiologiques Liés à un Rejet Concerté de Technétium dans l’Environnement.- 33. Interaction entre Technétium et Molybdène dans l’Inhibition de la Nitrogénase d’Azotobacter Chroococcum.- 34. Toxicity of Long-term Application of Dietary Technetium to Rats and their Offspring.- Summary of the Oral Presentations.- Summaries of the Discussions of the Working Groups.- List of Participants.