Plutonium and Uranium in Human Bones from Areas surrounding the Semipalatinsk Nuclear Test Site

摘要

To evaluate the present levels of 239,240Pu and U in residents living near the Semipalatinsk nuclear test site, more than 70 bone samples were obtained at autopsy. The subjects ranged in age from 30 to 86 years (mean 59.3±12.9). Most of the samples consisted of victims who died of various diseases. Plutonium and U were radiochemically separated and determined by α-ray spectrometry. The mean concentrations of 239,240Pu and 238U observed were 0.050±0.041 mBq/g-ash (vertebrae 71, long-bones 18) and 0.28±0.13 mBq/g-ash (22.8±10.6 μg U/kg-ash) (vertebrae 58, long bones 16), respectively. The present 239,240Pu levels were within the range found for human bone samples from other countries due solely to global fallout in the early 1980s. The average U concentration was close to the estimate (mean 22.5 μg U/kg-ash) for the UK, and about 10 times higher than those estimated for residents in New York City and Japan. By assuming that the average concentration of 239,240Pu in bone samples is the value at 45 years after instantaneous inhalation in 1955, the initial total intake and the effective dose for 45 years were estimated as 10 Bq and 0.2 mSv, respectively. The annual intake of total U (234,235,238U) and its effective dose for 60 years were estimated as 30 Bq for adult and 0.1 mSv, respectively, for chronic ingestion.