[Cytogenetic effect in lymphocytes in astronauts after 2 lengthy flights on board MIR orbital station].

The cytogenetic analysis of peripheric blood of cosmonauts who participated in the 196- and 194-day Mir missions evidenced increases in the number of aberrant cells and the rate of chromosomal aberrations. However, in most cases these were not statistically significant as compared to control values. Nonetheless, the lesions in cell chromosomal apparatus can amplify the risk of delayed consequences of exposure to ionizing radiation.