Results of long-term genetic monitoring of animal populations chronically irradiated in the radiocontaminated areas

The artificial geochemical land where all organisms lived and will live under the conditions of increased level of radiation was set up due to the Chernobyl disaster in 1986. An urgent necessity for studying the various biological effects of chronic influence of low intensity radiation on both individual organisms and populations arose. Combined cytogenetic and radioecological investigations in wild populations of terrestrial small mammals (bank vole = Clethrionomys glareolus, Schreber and yellow-necked mouse = Apodemus flavicollus, Melchior) and in laboratory mice have been carried out by our laboratory since 1986. Our test organisms have contacted closely with low intensity radiation in the radiocontaminated areas of Belarus and absorbed low whole-body dose. We study the following problems: dynamics of radionuclide concentration in wild populations of small rodents; dynamics of mutation process in somatic and germ cells over many generations as well as embryonal lethality; dynamics of population density, age and sex structure of mammalian populations. The large part of results obtained are presented here. (J.P.N.)