[Hereditary chromosome instability in the common vole (Microtus arvalis) from the region of the Kyshtym nuclear accident--fact or hypothesis?].

In bone marrow cells of common voles living within the Eastern Urals radioactive track (EURT) and adjacent area, the frequency of chromosomal aberrations was higher than in cells of control animals. In several animals, the proportion of aberrant cells was significantly higher; cells with multiple chromosomal lesions prevailed among the aberrant cells. Frequency of chromosomal aberrations did not depend on the absorbed dose of beta-radiation. Taking into account the radiation background in trapping sites, the level of cytogenetic damage in the animals studies should be considered unexpectedly high. Outside the EURT, two voles with mutant karyotypes were caught. It was hypothesized that carriers of hereditary chromosome instability appeared in the population studies as a result of exposure to ionizing radiation.