The linear, no-threshold hypothesis linking health effects to tissue absorbed dose appears principally inapplicable at low doses

The probability of detrimental effects (R), such as cancer induction in irradiated multicellular tissue, from low-dose exposure to ionizing radiation is conventionally related to absorbed dose (D) to tissue by the proportionality constant {alpha} for a given type of radiation: R = {alpha}{center_dot}D This expression formalizes the linear no-threshold hypothesis stating that radiation exposure may be harmful at all dose levels. This paper challenges the validity of this hypothesis by examining tissue responses as an integral consequence of multiple- and various-cell responses especially at low dose levels.