The use of chromosomal aberration analysis to asses radiation doses at long periods of time elapsed after exposure

"Radiation and Risk", 1992, vol. 2, pp. 110-118


Sevan'kaev A.V., Moiseenko V.V., Zhloba A.A.
Medical Rediologica! Research Center RAMS, Obninsk


The paper presents the results of radiation dose assessment based on study of unstable chromosome aberrations in peripheral blood lymphocytes at long terms after exposure. Cytogenetic data on nearly 700 liquidators (2 of them were heavily exposed to radiation field of high intensity) were used, 200 cells were scored for each person whenever possible. The dose assessment has been performed with the Qdr method considering the yield of dicentrics and centric rings only from cells containing unstable chromosomal aberrations and due to this being independent of the period of time elapsed from the moment of radiation exposure to cytogenetic examination. For the 2 persons exposed to intensive fields of radiation the dose estimates obtained by means of chromosome aberration dose assessment closely correspond to those provided by both physical dosimetry and ESR-analysis of tooth enamel. Apart from these 2 persons, other liquidators from the studied cohort have shown a lower level of chromosome damage Since not less than 20 cells containing unstable chromosome aberrations should be registered for each person to make the Qdr method applicable, individual doses could not be estimated, taking into account the current average level of cytogenetic damage. However, the Qdr method is applicable to the collective dose assessment. Collective dose estimates obtained for the above mentioned cohort of liquidators are presented.

A small proportion of liquidators (5 out of 705) have shown single metaphases (one metaphase each) containing a large number of chromosomal abnormalities. These "multidamaged" cells might significantly affect the collective dose estimate. Taking into account that the origin of these cells is unknown, but hardly could be attributed to radiation from the Chernobyl accident, the data on these 5 liquidators were ignored when assessing the collective dose. Estimates obtained for collective doses in the studied cohorts of liquidators correspond closely to the data of Epidemiologic Registry.

Generally it may be concluded that the level of chromosome damage observed in liquidators is much higher than that observed in controls. The cytogenetic data could be used to form the "risk groups" in the studied cohorts. However, because of time elapsed and consequent decline of aberration frequency, as well as the relatively low levels of exposure, individual dose assessment based on unstable aberration scoring could be hardly carried out. Collective doses could be estimated with satisfactory precision. Individual doses could be assessed for persons exposed to high doses.

Key words
Verifications, absorbed doses, radiation, frequency, chromosomal aberrations, lymphocytes, peripheral blood, liquidators, cytogenetic examination, dose assessment, Qdr method, collective doses.


1. Sevankayev A.V., Kozlov V.M., Guzeev G.G., Izmaylova N.N. The frequency of spontaneous chromosomal aberrations in the culture of human leukocytes. Genetics. 1974, vol. 10. PP. 11-120.

2. Sevankayev A.V. Radiosensitivity of human lymphocyte chromosomes in the mitotic cycle. M: Energoatomizdat Publ. 1987.

3. Awa А.А., Neel J.V. Cytogenetic "rogue" cells: what is their frequency, origin, and evolutionary significance?. Proc. Natl. Acad. Sci. USA. 1986. Vol. 83. PP.1021-1025.

4. Bauchinger M., Schmid E., Braselmann H. at al Time-effect Relationship of Chromosomal Aberrations in Peripheral Lymphocytes after Radiation Therapy for Seminoma. Mutation Research. 1989. Vol. 211. PP. 265-272.

5. Biological Dosimetry: Chrromosomal Aberration Analysis for Dose Assessment. Vienna:IAEA. 1986, Technical Report Series No. 260.

6. Buckton K.E., Court Brown W.M., Smith P.G. Lymphocyte Survival in Men treated with X-rays for Ankylosing Spondilytis. Nature. 1967. Vol. 214. PP. 470-473.

7. Lloyd D.C., Edwards A.A. Chromosome Aberrations in Human Lymphocytes: Effect of Radiation Quality, Dose, and Dose Rate// Radiation-Induced Chromosome Damage in Man. New York: Alan R. Liss, Inc. 1983. PP. 23-49.

8. Lloyd D.C., Edwards A.A., Natarajan A.T., Darrudi F. Biological Dosimetry Applied to in- vitro Simulated Partial Body Irradiation,. Treatment and Biological Dosimetry of Exposed Persons. Post-Chernobyl Action. K. Chadwick and G. Gerbert Eds. Report No. 12558. Luxembourg: CEC. 1991.

9. Neel J.V., Awa A.A., Kodama Y., Nakano M., Mabuchi K. "Rogue" Lymphocytes among Ukranians not Exposed to Radioactive Fall-out from the Chernobyl Accident: The Possible Role of this Phenomenon in Oncogenesis, Teratogenesis, and Mutagenesis. Proc. Natl. Acad. Sci. USA. 1992. Vol. 89. PP. 6973-6977.

10. Ramalho A.T., Nascimento A.C.H. The Fate of Chromosomal Aberrations in 137Cs-Exposed Individuals in the Goiania Radiation Accident. Health Physics. Vol. 60. PP. 67-70.

11. Sevan'kaev A.V., Tsyb A.F., Lloyd D.C. at all "Rogue" Cells Observed in Children Exposed to Radiation from the Chernobyl Accident. Int. J. Radiat. Biol. 1992 (in print).

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