The radiation environment and its effect on the spectral response requirements of environmental dosemeters.

The determination of dose equivalents from environmental radiation is most frequently performed on a TLD basis. As a matter of common language between authorities, customers and manufacturers of TLD systems, recommendations and standards are being set up by international and national bodies. Here, comments are made on the present state of standardisation by focussing attention on the energy range required. The different lower energy limits found are reviewed and discussed in terms of the metrologically feasible and with reference to a dose equivalent quantity as stated in ICRU 39

Alanine dosimetry - a versatile dosimetric tool.

ESR spectroscopy using amino acid alanine as sensor material has developed ability, in the recent past, for outstanding and versatile dosimetry. Physically the method makes use of the radiation induced generation of free radicals in alanine: ESR spectroscopy serves for identification of the free radical type and for quantification of its concentration which corresponds linearly to the given radiation dose, in a wide dose range. Alanine/ESR dosimetry has reached acceptance as a leading technology in high-dose standardisation, world-wide. Currently it is high-ranking in therapy level dosimetry for clinical applications and used for reference metrology in postal dose intercomparisons aiming at both high energy photon and electron radiation. Alanine/ESR dosimetry has qualified to compete Fricke dosimetry and complement ionization chamber dosimetry, with respect to high reliability, low uncertainty, small size and easy handling. The present review reports on the evolution of alanine/ESR dosimetry and on its established dosimetric properties up to the current state-of-the-art. The review has an eye also on international reports and recommendations dealing with alanine/ESR dosimetry, e.g. published by ICRU, ISO, IAEA

ESR: Global player in dosimetry.

Sixty-five years of research have substantiated ESR spectrometry to encompass reliably major key sector areas in quantifying radiation, e.g. transfer and secondary standard dosimetry, cancer treatment and radiation processing, dosimetry control of food irradiation and retrospective dosimetry of accidentally exposed humans or animals using their tooth tissues. Quantifiable ESR signals have also been obtained from bricks, wood, soil and other environmental materials, after radiation accidents. The ESR based individual dosimetry was recognized early on as an excellent tool for studying potential long-term health effects as a precursor for epidemiological risk estimates concerning, e.g., Chernobyl population and liquidators, South Ural population and Mayak nuclear workers, Hiroshima A-bomb survivors, residents near the Semipalatinsk nuclear test site and some other cases of radiation accidents, e.g. Toka-mura, Japan and Goiania, Brasil. Detailed methods are now summarized in IAEA-TECDOC-1331 and ICRU Report 68. In addition ESR has provided a successful tool for identifying irradiated food and for archeological and geological dating of hominid sites from the paleolithic through to more recent times. The potential and diversity of ESR physical and biophysical dosimetry appears unrivalled, world-wide, by any of the other established traditional dosimetry methods. While ESR dosimetry methods are already used routinely for invasive accident dose reconstructions, there is a strong need for evaluating its metrological potential as a non-invasive biophysical dosimetry with human tissues in situ and thereby using ESR dosimetry in situations of life threatening incidents for individuals who do not wear special physical dosimeters.   Recognizing the global impact of security concerns, a fast-processing biophysical dosimetry strategy and standardization deserves urgent attention and innovative methods development. In vivo dosimetry measurements on teeth and bones for rapid response triage, in order to identify casualties who could develop acute clinical effects, is the subject of a novel ESR retrospective dosimetry method presently under fast development using L-band (1.2 GHz). Any new ESR technology should complement biological dosimetry by cytogenetics and hopefully plug the time gap caused by the need for processing of blood and cell scoring.   Apart from some mutual agreements in the world on assistance networking using cytogenetics, no international standard currently exists for large-scale emergency measurements. Yet, unexpected disasters ranging from potential nuclear accidents to radiological terrorism underscore the importance of metrological consensus, e.g., on biological and biophysical dosimetry, and international coordination in emergency cases. Radiological preparedness, anticipating situations of population triage, is a vital part of a country’s infrastructure

ESR spectrometry: A future-oriented tool for dosimetry and dating.

  ESR spectroscopy is currently taking root as a key technology in dosimetry, dating and imaging. In dosimetry, it competes with cytometry in the fields of biological dosimetry and retrospective dosimetry, leads in high-level reference and routine dosimetry, is high-ranking among the methods to identify radiation preserved foods, represents a method of choice to date geological, archaeological and paleontological materials back millions of years, and has demonstrated capacity for imaging. Further scientific and technological progress as predicted in the recent past (Appl. Radiat. Isot. 52 (2000) 1023) is reviewed here. Additionally, the review is expanded to include international reports and recommendations on ESR dosimetry and dose reconstruction, under way at the American Society for Testing and Materials (ASTM), the International Organisation of Standards (ISO), the International Atomic Energy Agency (IAEA) and the International Commission on Radiation Units and Measurements (ICRU). Emphasis is placed on interpretation of tooth enamel doses in terms of organ and effective doses, using CT-based virtual humans. The future of EPR spectroscopy for in situ dose measurements is noted, depicting a non-destructive in vivo dosimetry applicable directly to individuals, but also to hominid and animal fossils for direct dating. &nbsp