Chromosomal dosimetry for some groups of evacuees from Prypiat and Ukranian liquidators at Chernobyl

Lymphocytes from some evacuees from Prypiat and clean-up workers (liquidators) have been studied for chromosomal aberrations. When dicentric yields from subjects are pooled in various ways, by date of evacuation, date of working at Chernobyl or delay in blood sampling, the resultant mean dose estimates are higher than have been generally assumed from dose reconstructions for Prypiat citizens or personal dosemeters worn by liquidators. Some of this difference may be due to the selection of subjects for study. However, dicentrics in one cohort of randomly selected evacuees, sampled very promptly, indicated a mean dose of ~ 300 mGy which is significantly in excess of mean dose reconstructions of ~ 10-20 mSv.