Radiation exposure refers to the amount of ionizing radiation that a person comes into contact with. This can occur from natural sources, such as cosmic rays and radon gas, or from man-made sources, including medical imaging procedures like X-rays and nuclear power plants. The effects of radiation exposure depend on the dose and duration of exposure. Low levels may not cause immediate harm, while high levels can lead to serious health issues, including radiation sickness and an increased risk of cancer. Safety measures are important to minimize unnecessary exposure in various environments.