Radiation biology. Radioecology
ISSN: 0869-8031

Archives → 2020 → V. 60. №3. → pp. 249–264

Article

Cytogenetic Effects in Crested Hairgrass Populations from the Technical Site “4A” of the Semipalatinsk Nuclear Test Site where Combat Radioactive Substances Were Tested

K. S. Minkenova^a, Z. A. Baigazinov^a, S. A. Geras’kin, a^bnd A. N. Perevolotsky^b

^aInstitute of Radiation Safety and Ecology, NNC, Kurchatov, Kazakhstan. ^bRussian Institute of Radiology and Agroecology, Obninsk, Russia

Abstract

An assessment of cytogenetic effects in the crested hairgrass was performed in 38 experimental points of the 4A site of the Semipalatinsk test site (Kazakhstan), which did not differ in soil characteristics and heavy metal contamination, but contrasted in level of radioactive contamination. At the «4A» site in 1954–1957 military
radioactive substances were tested. Absorbed by plants doses at this site vary in the range of 0.00014–15 Gy, ⁹⁰Sr makes the main contribution. It was shown that the dose dependence splits into two sections, within which the nature of the change in the frequency of cytogenetic disorders with the dose is fundamentally different.
In the range of 0.05–250 mGy, cytogenetic alterations frequency does not statistically significantly differ from the control level. The results obtained suggest the presence of a threshold dose below which the frequency of cytogenetic effects in natural plant populations remains at a spontaneous level. Increasing the dose above this limit leads to a linear increase in the frequency of cytogenetic abnormalities. The main contribution to the formation of cytogenetic effects is made by double bridges, which serves as additional evidence of the radiation nature of changes observed in the crested hairgrass populations.

Keywords

the Semipalatinsk test site, radioactive contamination, 90Sr, cytogenetic abnormalities, crested hairgrass