A SURVEY OF CHROMOSOMAL-ABERRATIONS IN LYMPHOCYTES OF CHERNOBYL LIQUIDATORS

Chromosomal aberrations in lymphocytes of 875 Chernobyl liquidators ha ve been scored and by comparison with control subjects the dicentric p lus ring and excess acentric fragment frequencies are higher for perso ns who worked in the exclusion zone in 1986-1988 but not in 1989. Aber ration yields are too low for individual biological dosimetry but, aft er taking account of the time interval between irradiation and blood s ampling, the dicentric plus ring frequencies indicate average doses fo r 1986, 1987 and 1989 in good agreement with the annual averages in th e Obninsk Registry. For 1988 the cytogenetic data indicate a significa nt higher average dose than the Registry. Liquidators who were not iss ued with a personal film badge tend to have higher aberration yields t han those for whom badge data are recorded. This is particularly evide nt for those persons who worked in the first three months after the ac cident where physical dosimetry data are less complete or reliable. Th ese persons probably experienced the highest exposures of all liquidat ors and the chromosomal data suggest an average value of about 300 mGy .