Article

Complex experimental research on internal tooth dosimetry for the Techa River region: A model for 90Sr accumulation in human teeth formed by time of intakes

{ "0" : "Medical Radiological Research Center, Korolyov str., 4, Obninsk 249036, Russia" , "1" : "Urals Research Center for Radiation Medicine, Medgorodok, Chelyabinsk 454076, Russia" , "3" : "Internal dosimetry" , "4" : "External dosimetry" , "5" : "EPR/ESR" , "6" : "Tooth enamel"}
Radiation Measurements (Impact Factor: 0.86). 01/2006; http://dx.doi.org/10.1016/j.radmeas.2005.12.003,. DOI: 10.1016/j.radmeas.2005.12.003

ABSTRACT Samples of calcified tooth tissues (enamel, root and crown dentine) collected from the Techa riverside population exposed to radiation caused by radioactive releases from the nuclear weapon plant in South Ural were investigated. Accumulated absorbed dose in the samples was measured using the EPR-spectroscopy method. Beta activity of the samples containing radioactive 90Sr was measured by the method of low background anti-coincidence thin scintillating detection. High correlation between absorbed dose and beta activity was observed for enamel and root dentin but not for crown dentin. Otherwise, poor correlation was observed between absorbed doses as well as between beta activities for different tooth tissues of the same tooth. The results of dose measurement by EPR spectroscopy are analysed with the use of Monte Carlo simulation of dose formation due to 90Sr incorporated in tooth tissues taking into account biological elimination of 90Sr. Influence of 90Sr distribution in the tooth body on absorbed dose is discussed.

0 Bookmarks
 · 
70 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The requirements for biodosimetric techniques used at long times after exposure, i.e., 6 months to more than 50 years, are unique compared to the requirements for methods used for immediate dose estimation. In addition to the fundamental requirement that the assay measures a physical or biologic change that is proportional to the energy absorbed, the signal must be highly stable over time to enable reasonably precise determinations of the absorbed dose decades later. The primary uses of these biodosimetric methods have been to support long-term health risk (epidemiologic) studies or to support compensation (damage) claims. For these reasons, the methods must be capable of estimating individual doses, rather than group mean doses. Even when individual dose estimates can be obtained, inter-individual variability remains as one of the most difficult problems in using biodosimetry measurements to rigorously quantify individual exposures. Other important criteria for biodosimetry methods include obtaining samples with minimal invasiveness, low detection limits, and high precision. Cost and other practical limitations generally prohibit biodosimetry measurements on a large enough sample to replace analytical dose reconstruction in epidemiologic investigations. However, these measurements can be extremely valuable as a means to corroborate analytical or model-based dose estimates, to help reduce uncertainty in individual doses estimated by other methods and techniques, and to assess bias in dose reconstruction models. There has been extensive use of three biodosimetric techniques in irradiated populations: EPR (using tooth enamel), FISH (using blood lymphocytes), and GPA (also using blood); these methods have been supplemented with luminescent methods applied to building materials and artifacts. A large number of investigations have used biodosimetric methods many years after external and, to a lesser extent, internal exposure to reconstruct doses received from accidents, from occupational exposures, from environmental releases of radioactive materials, and from medical exposures. In most applications, the intent has been to either identify highly exposed persons or confirmed suspected exposures. Improvements in methodology, however, have led many investigators to attempt quantification of whole-body doses received, or in a few instances, to estimate organ doses. There will be a continued need for new and improved biodosimetric techniques not only to assist in future epidemiologic investigations but to help evaluate the long-term consequences following nuclear accidents or events of radiologic terrorism.
    Radiation Measurements. 01/2007;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Mounting a successful online training course takes a concerted effort by a team of experts in diverse fields. This paper describes the development of a program designed to teach business English and the concepts of business communication to an international audience via the Internet. This online business English course is being developed by a private corporation (Virtual Languages Inc.), with the cooperative efforts of a university (the Florida Institute of Technology). Content experts, ESL (English as a second language) professionals, Web page designers, graphic artists and sound technicians, plus corporate officers, bring together the expertise needed to mount this innovative online course
    Professional Communication Conference, 1999. IPCC 99. Communication Jazz: Improvising the New International Communication Culture. Proceedings. 1999 IEEE International; 02/1999
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: When tooth enamel is exposed to ionizing radiation, radicals are formed, which can be detected using electron paramagnetic resonance (EPR) techniques. EPR dosimetry using tooth enamel is based on the (presumed) correlation between the intensity or amplitude of some of the radiation-induced signals with the dose absorbed in the enamel. In the present paper a critical review is given of this widely applied dosimetric method. The first part of the paper is fairly fundamental and deals with the main properties of tooth enamel and some of its model systems (e.g., synthetic apatites). Considerable attention is also paid to the numerous radiation-induced and native EPR signals and the radicals responsible for them. The relevant methods for EPR detection, identification and spectrum analyzing are reviewed from a general point of view. Finally, the needs for solid-state modelling and studies of the linearity of the dose response are investigated. The second part is devoted to the practical implementation of EPR dosimetry using enamel. It concerns specific problems of preparation of samples, their irradiation and spectrum acquisition. It also describes how the dosimetric signal intensity and dose can be retrieved from the EPR spectra. Special attention is paid to the energy dependence of the EPR response and to sources of uncertainties. Results of and problems encountered in international intercomparisons and epidemiological studies are also dealt with. In the final section the future of EPR dosimetry with tooth enamel is analyzed.
    Applied radiation and isotopes: including data, instrumentation and methods for use in agriculture, industry and medicine 11/2010; 68(11):2033-116. · 1.09 Impact Factor

Full-text

View
22 Downloads
Available from
May 27, 2014