RETROSPECTIVE DOSE ESTIMATES IN ESTONIAN CHERNOBYL CLEANUP WORKERS BYMEANS OF FISH

The present study deals with retrospective estimation of radiation dos es, among Estonian Chernobyl clean-up workers, by means of scoring sta ble translocations using the FISH technique. All persons investigated in this study were sent to the area in 1986 and the majority of them w ere selected to be among those with the presumably highest exposure do ses. In spite of the selection the estimated average dose is between 0 .2-0.3 Gy, thus not clearly above the officially permitted dose level of 0.25 Gy. Due to unforseen conditions during transport of the blood samples, both the number of persons available for analysis and the num ber of metaphases available for scoring were substantially reduced. Ho wever, unless this selection is linked with the potential aberration f requency of the cells involved, no bias is expected.