Retrospective Dosimetry of Some Populations Exposed After Chernobyl. Vadim V.Chumak, Ph.D., Head of Laboratory of External Exposure Dosimetry, Scientific Center for Radiation Medicine AMS Ukraine, Kiev, Ukraine, 254050, Melnikova 53, Kiev, Ukraine, e-mail chumak@leed1.kiev.ua
Chernobyl accident brought to life a number of epidemiological studies of effects caused by exposure to ionizing radiation. Among those, the most notable are follow-ups of leukemia and eye-cataract in Chernobyl liquidators. These studies critically depend on reliable dosimetry. Unfortunately, poor dosimetric monitoring at time of accident caused the need for extensive work on retrospective dose assessment. In case of liquidators, external exposure played dominant role and, therefore, external gamma and beta doses should be evaluated on individual basis. This task is being approached using variety of instrumental, biological and analytical methods. Official dose records, which are known to contain a fraction of low quality or even falsified information, need to be verified in order to filter reliable dose records. In addition, uncertainty of different methods of dosimetric monitoring needs to be evaluated retrospectively. When possible, individual doses of liquidators should be assessed using behavior and migration histories together with dose rate records. A screening procedure based on account of dose determining factors might be developed and utilized for evaluation of possible ranges of doses received by liquidators. Instrumental retrospective dosimetry is based on EPR spectroscopy of tooth enamel. Application this high precision technique requires, however, collection of teeth from exposed individuals; this task is being administered in Ukraine now. Applicability of FISH biodosimetry in the dose range below 250 mGy is being tested on respective cohort of liquidators now. Another challenging task is evaluation of beta dose to eye lenses of liquidators. This task would be approached by utility beta to gamma ratios specific for assumed conditions of exposure. At the later stages of retrospective dosimetry, organ (i.e. red bone marrow and eye lens) doses should be assessed with respect to the conditions of exposure (particularly in case of wearing shielding led aprons by some liquidators).
Go to . . .
1999 SRA-Europe Table of Contents
1999 SRA-Europe Author Index
Main Abstracts Menu Page
RiskWorld Home Page