Made with Xara Talk to us and ask the expert  Welcome to Operational Radiation Safety “Πάν μέτρον άριστον” The doses received by persons from artificial sources of radiation compared with those of natural sources are summarized below: What are the effects of exposure to radiation?  When radiation passes through material, it causes ionization which can damage chemical structures. If the material in question is biological material (such as  the cells that make up human organs and tissues) and if the damage occurs to critical chemicals within the cells (such as the DNA molecules making up the  chromosomes within the cell nucleus), the cell itself can be damaged. It should be noted that the cell and the DNA are undergoing physical and chemical  damage all the time (e.g. from temperature fluctuations and oxidation processes). However the cell and DNA have mechanisms to repair damage. The radiation  damage will usually be repaired by these normal cell repair processes; or the cell may be sacrificed. This is of not significance if the repair is successful or if  the number of cells killed is not large. However it is possible also that the DNA may be misrepaired; in the majority of cases, such mutated cells will also die.  However there is a small possibility that the cell survives and the mutation in the DNA is replicated as the cell divides. This can be the start of a multi-step  process that could eventually lead to formation of a cancer.