After-the-fact Radiation dosimetry from Inanimate Objects (EPR)

Project Summary

In the event of a terrorist act or an accident releasing ionizing radiation, it is critical to rapidly and efficiently determine the radiation exposure experienced by individuals in the affected area. Recent research has found that long-lived radiation induced unpaired electrons occurs in biological materials; these electrons can be measured by a technique termed electron paramagnetic resonance (EPR). In hard and/or dry tissues, such as bone or teeth, these resonances have been shown to be able to provide accurate dosimetry at doses as low as 80 cGy using isolated teeth. It may thus be possible to use EPR under the conditions that are likely to be present in the event of a release of radiation. This approach has been usefully applied for people exposed at places such as Hiroshima and Chernobyl even years after the exposure. It now is being extended to make measurements with the teeth still in the mouth. In addition to those studies, there is another approach using EPR dosimetry that could provide excellent sensitivity and ease of measurement. This approach uses non-living material such as articles of clothing, and other materials likely to be in the immediate vicinity at the time that a radiation exposure would occur. A variety of such materials have long-lived radiation-induced signals that are proportionate to dose. In this project we will systematically evaluate these materials for their usefulness in determining the radiation dose in the event of a terrorist act or an accident.

• Project Lead: Harold Swartz