Peculiarities of Hematopoiesis in small rodents from the Chornobyl Exclusion Zone on the background of extreme environment.

Radiobiological investigations of natural populations of Myodes glareolus (bank vole) from the Chornobyl Exclusion Zone, namely within a highly radioactive site of the Red Forest were carried out. The complex of hematological and cytogenetic parameters of the bank voles inhabiting the contaminated site was studied before the site was flooded, in 2012, and after it drained, in 2015. A significant increase in micronucleated polychromatic erythrocytes, alterations in bone marrow and peripheral blood cell counts were observed in the population of 2015 in comparison with the group of 2012 and animals from the reference site. It is supposed that prolonged flooding has affected the features of radionuclide contamination of the experimental site as well as population characteristics and resulted in the increase of the genotoxic effects observed in the renewed population of bank voles exposed to chronic radiation.