DOE program - Developing a scientific basis for responses to low-dose exposures: Impact on dose-response relationships

Abstract

The DOE Low Dose Radiation Research Program focuses on the biological mechanisms involved in the response of molecules, cells and tissues to low doses of both low and high-LET radiation (< 0.1 Gy). This research program represents a merging of new technologies with cutting edge biological techniques associated with genomics. This merger makes it possible to observe radiation-induced cellular and molecular changes previously undetectable. These observed low-dose responses not only define mechanisms of interaction of radiation with living systems, but are helping characterize the shape of dose-response relationships in the low-dose region. The research from this program is suggesting a new set of radiation paradigms regarding the involvement of radiation in the carcinogenic process. This manuscript will discuss the biological phenomena observed at low doses and speculate on how these may impact the shape of dose-response relationships in the low dose region. The phenomena include initial radiation-induced DNA damage and repair, changes in gene expression, adaptive responses and bystander effects. However, this information from the cellular-molecular level cannot be directly extrapolated to risks in human populations. This extrapolation must carefully take into consideration all levels of biological organization. Links must be developed between dose-response relationships at the cell and tissue levels and risk to human populations. The challenge and the ultimate goal of the Program is to determine if basic scientific data can be combined with more traditional epidemiological methods to improve the estimation of radiation risk from low level radiation exposures.