The latter half of the last century has been witness to a variety of release of radioactive materials from industrial and military activities or to overexposure of persons due to the improper use or disposal of ionizing radiation sources.
During the last thirty years, CW-EPR dosimetry has been established as a powerful method for retrospective assessment of ionizing radiation exposure of persons in the field of epidemiological studies or in the management of radiation accident [1,2]. This dosimetry technique based on the measurement and quantification of radio-induced radicals in materials such as tooth enamel, bone tissue, sugar, glass for example is of particular of relevance for past exposure (Hiroshima and Nagasaki survivors, witness of nuclear test) , for people chronically exposed (inhabitants of contaminated territory around Tchernobyl, Semipalatinsk, Techa river) , or in accidental circumstances when data from conventional personal dosimetry do not exist (persons from public exposed to orphan or lost radiation source, absence of wear of dosemeters, radiotherapy accident
In this presentation, a description of the different methodologies and material properties used for EPR retrospective dosimetry and the recent technical developments in L-band for tooth enamel in vivo measurements, as well as an overview of recent application cases both for prolonged and acute exposure will be presented.
 International Atomic Energy Agency, IAEA-TECDOC-1331 2002
 International Commission on Radiation Units and Measurements, ICRU Report 68, J. ICRU 2002, 2 (2)
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 Wieser, A., Vasilenko, E., Fattibene, P., Bayankin, S., El-Faramawy, N., Ivanov, D., Jacob, P., Knyazev, V., Onori, S., Pressello, M.C., Romanyukha, A.A., Smetanin, M., Ulanovsky, A., Radiat Environ. Biophys. 2006, 44, 279288
 I. Clairand, F. Trompier, J-F. Bottollier-Depois and P. Gourmelon, Rad. Prot. Dosim. 2006, 120, 500-505