WIDE-SCALE EPR RETROSPECTIVE DOSIMETRY - RESULTS AND PROBLEMS

The results of the first wide-scale application of electron paramagnet ic resonance (EPR) with tooth enamel for retrospective dosimetry for p ermanent residents of Borovskii and Zhukovskii districts (Kaluga regio n, Russia) are presented. Since these districts have never been radioa ctively contaminated, their population could be used for comparison st udies of the suitability of molars, premolars, canines and incisors fo r EPR dosimetry purposes. Altogether 136 samples have been investigate d. For molars and premolars (103 samples) a linear correlation between the dose absorbed in tooth enamel and the tooth age has been identifi ed. For incisors and canines no such correlation has been found; also, in this case, the doses absorbed in tooth enamel exceeded the dose va lues for molars and premolars. The data obtained may be connected with the exposure of front teeth to sunlight, which is supported by dedica ted EPR experiments with exposure to sunlight and laboratory ultraviol et (UV) radiation. The proposed interpretation and problem areas are d iscussed.