Some estimate of radiation dose is critical in the initial stages of triage after a terrorist nuclear event; this proposal will focus on the demonstration of a fast, portable, non-invasive instrument that will measure radiation dose to intact teeth by optical stimulation of luminescence (OSL). Our goal is to develop the necessary information on teeth: (a) to enable optimization of OSL measurement parameters; (b) to determine the range of person-to-person variability of OSL characteristics to gamma radiation, and (c) to demonstrate portable instrumentation capable of making measurements on teeth in the critical zone of 0.5 to 10 Gy. This demonstration will facilitate commercialization of an instrument that will enable medical personnel, in a radiation emergency situation, to distinguish people with low or no exposures from those requiring medical attention. There is currently no rapid method to make this identification. 1. Determine the uncertainty in whole body dose based on a unit dose to a molar, and for the different radiation types that are expected in RDDs. This set of calculations will provide the translation between OSL signals from the tooth and radiation impact to the individual. 2. Optimize signal-to-noise in OSL of irradiated porcine molars. At each of our three laboratories, we will use a variety of techniques, including the investigation of different excitation wavelengths, stimulation modes, and minor surface preparations on fresh porcine molars to optimize signal recovery. We will evaluate conditions of signal bleaching and determine the similarity of human teeth to porcine teeth. 3. Modify equipment at Oklahoma State University to optimize signal recovery at the tooth-fiber optic interface and optimize other components based on Aim # 2. 4. Characterize the age, gender and racial differences in OSL of teeth to radiation. Perform OSL dose response measurements in teeth.