74th Northwest Regional Meeting of the American Chemical Society, Portland, OR, June 16-19, 2019
USTUR director, Sergei Tolmachev, gave a presentation about uranium in the human body at the Northwest Regional Meeting of the American Chemical Society.
Uranium content, distribution, and biokinetics in human body
Sergei Y. Tolmachev (USTUR), Maia Avtandilashvili (USTUR), Ronald L. Kathren (USTUR)
Since 1968, the U.S. Transuranium and Uranium Registries (USTUR) has followed up occupationally-exposed individuals (volunteer tissue donors) by studying biokinetic and dosimetry of actinide elements. The USTUR currently holds data and tissue samples from six whole- and 27 partial-body donors with occupational uranium intakes. In this study, uranium tissue concentrations, body distribution, and biokinetics were compared between a group of individuals with occupational exposure to uranium and a group with chronic environmental-only intakes. Of two occupationally-exposed individuals, one had chronic inhalation intake of uranium oxide with natural composition, and another had acute inhalation of slightly enriched uranium hexafluoride. For all five individuals, the skeleton was a major deposition site where 51 ± 20% of systemic uranium was retained at the time of death. Average concentration in the skeleton was 4.0 ± 0.5 µg kg-1 for all individuals except the uranium hexafluoride case, where concentration in the skeleton was two times higher. Uranium was well-distributed among soft tissues with concentrations mostly clustered about 1 µg kg−1, except the uranium hexafluoride case, where median concentration was three times lower. For the uranium hexafluoride case, 235U/238U atom ratio analysis 65 years post-intake indicated that 95% of uranium in the lungs originated from accidental inhalation. This fraction was estimated to be 40% for the brain, 26% for the liver, 21% for the skeleton, and 7% for the kidneys.