Health effects of radiation incidents in the southern Urals.
This article discusses the most important information on health effects in the Urals region (Russia) of residents exposed to radiation from activities of a weapon plutonium separation plant. The population residing on the contaminated territory was exposed to chronic combined irradiation (external gamma-irradiation and internal irradiation due to Sr-90 and Cs-137). The red bone marrow (RBM) was the critical organ affected as a result of radiation events in the Urals. In the early period, after the discharges of radioactive wastes into the river Techa (about 3 M Ci) started, cases of chronic radiation sickness (CRS; 940 cases, in total), postirradiation reactions manifested by changes in blood parameters (e.g., leukopenia, thrombocytopenia, granulocytopenia), nervous system disorders, immunity changes and ostealgic syndrome were registered in a portion of those riverside village residents who had received the highest doses. Increased leukemia and cancer mortality and morbidity rates were noted among this population in later periods. No late effects were observed in residents exposed to an explosion in a radioactive waste depot in September, 1957 when radioactive wastes with about 20 M Ci of activity were released into the environment. Similarly, the offspring of the residents exposed on the Techa also did not display any late effects. The data about the possibilities of long-term (43-45 years after the start of exposure) biological indication of chronic internal exposure are presented. The methods used in the study include in situ fluorescent hybridization, analysis of mutations in the TCR gene of peripheral blood lymphocytes and erythrocyte mutations in the glycophorine A system. No dependence of genomic translocations and mutations in glycophorine A on cumulative exposure dose to RBM was traced.