(548c) An Evaluation of Organically Bound Tritium (OBT) Research

Tritium (³H) is radioactive isotope of hydrogen which decays via beta emission. Tritium incorporated into the tissues of plants and animals is referred to as organically bound tritium (OBT). Tritium ingested as tritiated water or water vapor (HTO) provides a limited dose that is subject to rapid turnover in animals. OBT, largely formed through photosynthesis, represents a more sustained dose when ingested. Elevated radiation exposure to DNA in cells can cause mutation that alter cell function and a serious may result, e.g., cancer. That is, just as water containing ordinary hydrogen and oxygen is a component of all living cells, HTO can also be incorporated into the cells of the body. Recent evidence demonstrates incorporation of OBT into plant cells so consumption by animals through the food chain is also possible. Research indicates that a fraction of ingested tritium can remain in the human body for more than ten years. However, dose standards for OBT do not exist and the literature highlights this gap.

The objective of this study is to assess organically bound tritium (OBT) research with a focus on impacts on organisms, including plants and animals. A thorough literature review of OBT was performed using various databases and reports from federal agencies. Research findings offer measures and influences of OBT however, standard protocols for assessing OBT is suggested.