Chromosome aberrations induced in human lymphocytes by U-235 fission neutrons. Part III: Evaluation of the effect of the induced alpha and beta activity on the chromosomal aberration yield.

AIM

Further experiments were performed to explain a difference in chromosomal aberration yield found between samples cultivated immediately after fission neutron irradiation and samples which were cultivated with 96 h delay after irradiation.

MATERIAL AND METHOD

Human peripheral blood samples were irradiated in mixed fission neutron/gamma field (1800 s) and biological effect assessed in the mean of analysis of unstable chromosome aberrations with a time delay in culturing cells of 12, 24, 48, and 96 h. Additional measurements were performed on irradiated and blank blood samples with the aim to detect any increase in alpha and beta activity after fission neutron irradiation. No difference was found. Results were compared to theoretically calculated values of the alpha and beta activity released from natural radioactive isotopes.

RESULT AND CONCLUSION

As a conclusion it is shown that in our experimental conditions the secondary effects resulting from nuclear transformations of natural or induced radioactive isotopes, recoil reactions and accompanying alpha, beta, and gamma radiation are not the reason for the increase observed in chromosomal aberration yield in blood samples cultured with a time delay of at least 24 hours.