Radiation Effects Physical and Chemical Effects of Ionizing Radiation Ionizing radiation is so named because its initial interaction with matter is the ejection of an orbital electron from an atom, forming a pair of ions with opposite charges. Radiation passing through living cells will ionize or excite atoms and molecules in the cell structure. When these radicals and ions interact with other cell materials, damage can result. Certain levels of cellular damage can be repaired by the cell.
Further levels can result in cell death.
May directly involve and damage biologically important molecules in the cell - Direct Effects . Damage to the DNA molecule or a chemical change in other cellular material are the primary results. Damage to the DNA molecule can result in somatic mutations that may show up years after the exposure or genetic mutations that require several life spans to appear. May initiate a chain of chemical reactions, mediated through cellular water, leading to ultimate biologic damage - Indirect Effects . An hydroxyl poisoning effect on the cell membrane results in a change in its permeability.