The Follow-up Study of Chromosomal aberrations in Chernobyl Clean-up Workers

A cytogenetic study was carried out on 359 clean-up workers who worked at the Chernobyl station in 1986-1989. The investigation was performed 6-12 years after irradiation. Chromosome type damages, i.e. double fragments, dicentrics and rings were significantly increased in the clean-up workers compared to the control. Chromatid exchanges were found only in the clean-up workers. A temporal change of radiation makers was also investigated based on the data of 243 persons who worked at Chernobyl in 1986. The temporal variation of dicentric frequency shows an inexplicable tendency towards the increase of dicentrics rate for the period of 8-12 years after irradiation. The association between the frequency of different types of chromosomal aberrations and such variables as smoking habits, coffee, tea, alcohol consumption, etc. was also analysed using a stepwise multiple regression analysis. A statistically significant association was only observed between smoking and chromatid exchanges. This type of aberrations was significantly higher in the smoking subgroup than in the non-smoking subgroup of the clean-up workers. The fact of an increased level of unstable chromosomal aberrations in a remote period after irradiation allows us to suppose that other pathways of genomic burden may exist in addition to straight radiation action at the time of irradiation