Plutonium in the Ozyorsk population.

Results of the long-term autopsy studies on plutonium body burden in the population of Ozyorsk situated in the vicinity of the radiochemical plant of the Mayak Production Association (Russia) have been presented. The data were obtained from radiochemical analysis of the soft tissue and bone samples collected at the autopsy of 239 non-occupational individuals for the period 1975-2003. The dynamics of plutonium accumulation in the Ozyorsk population is associated with the environmental contamination due to radioactive releases from the Mayak Production Association. Plutonium body burden and its distribution between the respiratory tract and extrapulmonary organs depend on the residence time of individuals in the city. Since the early 1950s, plutonium body burden in the Ozyorsk population was linearly increasing at the almost constant rate of accumulation and amounted to 5.8 Bq at 35 y after the beginning of residence in the city that was several tens of times higher than background levels of fallout plutonium. Distribution of plutonium in the body was also studied in Ozyorsk population. Plutonium deposition fraction in the respiratory tract did not exceed 11% of the body burden in individuals with short residence times (1-9 y) and is halved for increasing residence times more than 10 y. The average skeleton:liver ratio was 65:20 = 3.25.