[Age-related radiosensitivity of the crystalline lens in chronic experimental internal irradiation with 137Cs at low doses].

Internal whole-body irradiation of mice for 1 year with incorporated 137Cs at a dose of 0.5 eV was shown to make a significant cataractogenic effect on the lens. By annual rate this dose exceeded the existing maximum permissible dose only three times and was less than 10% of a cumulative dose for professionals having to do with ionizing radiation which they can accumulate at the maximum permissible dose level in annual irradiation for 50 years. The time of recorded lenticular opacity reduced and a degree of observed changes increased in the study groups as compared to the unirradiated control group indicating the involvement of a radiation factor in their development. More pronounced sensitivity of the mouse lens to chronic radiation exposure in the second half of the life than in the first half was noted.