THE PHYSICAL BASIS OF THE EFFECTS OF IONIZING RADIATION (X-RAY AND GAMMA RAYS) ON THE ORGANISM

Abstract

X‑rays and gamma rays are forms of high‑energy electromagnetic radiation. They belong to the category of indirectly ionizing radiation because the photons themselves carry no electric charge and do not produce ionization directly as they traverse matter. Instead, they transfer energy to atomic electrons, setting them in motion. These secondary charged particles, primarily electrons, are responsible for the vast majority of ionizations and excitations that occur in biological tissues. This fundamental two‑step process—photon interaction followed by electron‑mediated energy deposition—determines the entire chain of events that leads to radiation‑induced biological effects.