Study of the Individual Radiosensitivity in Humans Based on the Assessment of the Frequency of Chromosome Aberrations and Micronuclei in Peripheral Blood T Lymphocytes

The influence of low-dose ionizing radiation on a human being is increasing in the modern world (medical diagnostics etc.). The issue of the effect of low-doses on human health is topical and controversial. It is known that in the population up to 15% of people react to radiation exposure differently from what has been expected, which, according to the published data, happens owing to their genome peculiarities. The objective of the current study was to investigate the influence of chronic lowdose rate exposure (doses to red bone marrow varied within the range 3—4600 mGy) of the Techa River residents (South Urals) on the radiosensitivity of T cells in vivo and in vitro under additional gamma exposure of peripheral blood T lymphocytes (0.5, 1, and 2 Gy). Such cytogenetic parameters as frequency of unstable chromosome aberrations and micronuclei were used as irradiation markers. Persons were considered radiosensitive if the obtained values of the analyzed parameters for them exceeded the 90% percentile. On the basis of the findings of the performed study, the following conclusions were drawn: about 10% of donors demonstrated increased radiosensitivity; moreover, the effect did not depend on the dose of chronic exposure; no age dependence of radiosensitivity in the studied age range (49–89 years) of the donors was revealed. In most cases, we did not detect a reproducible radiosensitivity effect in the same donor under different irradiation regimes.