Speaker
Description
The United States Transuranium and Uranium Registries (USTUR) was established in 1968 by the U.S. Atomic Energy Commission. The Registries collect post-mortem tissue and organ samples, including teeth, from occupationally exposed individuals who voluntarily donate their bodies. By maintaining comprehensive dosimetry records and bioassay data, the USTUR serves as a unique resource for verifying historical occupational dose records.
Electron paramagnetic resonance (EPR) dosimetry in tooth enamel and bone is a well-established method for measuring lifetime doses of external radiation. Recent EPR measurements conducted on tooth and bone samples from USTUR donors revealed a significant discrepancy between the EPR-measured doses and the official personal doses recorded at worksites.
Furthermore, we observed significant variation in EPR-measured doses among multiple samples collected from the same individual. These variations may indicate additional exposure to the head and neck region relative to other parts of the body, such as the torso, where personal dosimeters are typically worn. This localized exposure could explain the significant differences between the doses derived from EPR measurements and those reported by the worksites.