Keywords: intervals, small doses, radionuclide, plateau, blood lymphocytes, genetic damage, DNA repair, ionising radiation, low radiation, human health, dose response, dependence curves, cytogenetic indices, in vitro irradiation
Peculiarities of dose-response dependence curves for cytogenetic indices after in vitro irradiation of human peripheral blood lymphocytes with ionising radiation of different types
For the purpose of investigating how ionising radiation of different types (α-, β- and γ-) affects human peripheral blood lymphocytes the latter were irradiated in vitro using 60Co, 3H and 239Pu as radiation sources. Investigated cytogenetic indices were as follows: frequency of aberrant cells, sum of chromosome aberrations, frequency of chromosome exchanges – dicentrics. For all of them dose-response curves tend to the formation of a plateau at doses 0.05–30 sGy, thus correlating with the results of Pohl-Ruling et al. and Luchnik and Sevankajev. Based on the results reported, the relative biological efficiency (RBE) was estimated for β-irradiation of tritium and made up 1, 2–3 in comparison with that of γ-irradiation. The RBE for α-irradiation was about 16 times greater than that of γ-irradiation. These data correlate with earlier received by Edward et al. (1980). Results found after α-irradiation are less statistically significant than for γ- and for β-irradiation due to small amount of analysed metaphases, it could be connected with toxic effect of plutonium, oppressing cell division.