Radiation exposure refers to the amount of ionizing radiation that a person or object receives. This can come from natural sources such as the sun, or man-made sources like medical imaging equipment or nuclear accidents. The amount and type of radiation received can vary greatly depending on factors such as distance from the source, shielding materials used, and duration of exposure. Exposure to high levels of ionizing radiation can increase the risk of developing cancer and other health problems, which is why it's important for individuals in occupations with higher radiation exposure risks (such as radiologists or nuclear power plant workers) to take precautions to minimize their exposure.