[Biological effects in natural populations of small rodents in radiation-polluted territories. Description of sites. Dynamics of concentration of gamma-emitting radionuclides in populations of two species of small mammals].

It has been revealed that dynamics of gamma-emitting radionuclide concentration in consecutive generations of two species of wild rodents (European bank vole and yellow-necked mouse) is characterised by the phases of an increase, a maximum content (peaks) and a decrease over 10 years after the Chernobyl accident. The peaks of specific activity of gamma-emitting radionuclides in populations in the areas with different densities of radio-contamination falls not on the first year but on the next ones (1987-1989) after the catastrophe, i.e. are observed in the subsequent (3-8) generations of animals. The revealed shift of maximum of radionuclide concentration in comparison with the maximum of their fallout is likely caused by an increase in radionuclide biological availability.