Tritium in plants: A review of current knowledge

The aim of this paper is to provide an overview of the literature regarding the fate of tritium in plants. At first, some prerequisites about the sources, chemical and physical characteristics, biological effects and potential risks associated to tritium are presented. The general scheme of tritium transport and cycling in the environment, the different tritium fractions in biological organisms and the corresponding techniques for sampling and measurement are discussed. Then, the main processes of uptake, incorporation and conversion of tritium into plants are described, based on experimental data. As tritium incorporated into the organic fraction may be the major contributor to the dose of radiation received following its ingestion by man, the biological mechanisms and kinetics of organically bound tritium (OBT) production are a major focus. Some predictive models of short-term or chronic exposure are described. Finally, the pending questions, concerning the fate of tritium in plants, are tackled.