Radiation biology. Radioecology
ISSN: 0869-8031

Archives → 2021 → V. 61. № 4 → pp. 353-366

Article

Cytogenetic Anomalies Blood Lymphocytes in Siberian Group of Chemical Enterprises Exposed to Occupational Irradiation

D. S. Isubakova^a, M. V. Khalyuzova^a, N. V. Litviakov^a,b, E. V. Bronikovskaya^a, T. V. Usova^a, A. B. Karpov^a, R. M. Takhauov^a

^aSeversk Biophysical Research Center, Seversk, Russia ^bTomsk Cancer Research Institute, Tomsk, Russia

Abstract

We have previously published data on cytogenetic anomalies in 657 employees of the Siberian Group of Chemical Enterprises. In this work, using a similar design, we studied the spectrum and frequency of cytogenetic anomalies in 1,047 healthy workers of the Siberian Group of Chemical Enterprises, depending on age, gender, type of radiation and external radiation dose. In a larger sample, it was confirmed that the frequency of cytogenetic anomalies does not correlate with the gender of workers. There is a correlation with age for aber-rations of the chromosomal type, dicentric and ring chromosomes. For the induction of cytogenetic anomalies, the determining factor was chronic external exposure to γ-radiation. With an additional radiation load due to the incorporated 239Pu in the blood of workers with combined irradiation, in comparison with workers exposed only to external irradiation, the frequency of cytogenetic anomalies was reduced. For aberrant cells, chromosomal aberrations, dicentric chromosomes, chromosomal (paired) and chromatid (unpaired) fragments, as well as chromatid exchanges, the dose dependence had a nonlinear S-shaped character. Hormesis has been shown for aberrant cells, chromosomal aberrations, and chromosomal fragments, and has not been confirmed for chromatid fragments. The threshold level of ionizing radiation for increasing the frequency of cytogenetic anomalies depends on their type and was realized in the range of 10–200 mSv. A expressed plateau was observed in the dose range 100–800 mSv. The frequency of cytogenetic anomalies increased in direct proportion to the dose of external irradiation: after 500 mSv for dicentric chromosomes and after 800 mSv for other types. For ring chromosomes, abnormal monocentric chromosomes, multi-aberrant cells, and polyploid cells, dose dependence has not been established.

Keywords

Cytogenetic anomalies, ionizing radiation, external and internal exposure, dose dependence