[Biological effects in natural populations of small rodents in radiation contaminated areas. The frequency of bone marrow polyploid cells of bank voles in different years following Chernobyl accident].

On the basis of the metaphase analysis results, the peculiarities of dynamics of the genome mutation frequency (polyploid cells) were studied in bone marrow of bank voles inhabiting the areas with different radiocontamination level due to the Chernobyl accident (8-1526 kBq/m2 for 137Cs) in 1986-1991. Unexpectedly high frequencies of polypoid cells exceeding the pre-accidental level by a factor of 10(1)-10(3) were recorded in all populations studied. Relationship between the frequency of the parameter studied and the concentration of radionuclides incorporated in animal carcasses was proved. A statistically significant rise in the frequency of genome mutations with the time was revealed up to 1991, i.e. approximately to 12th post-accidental animal generation.