This document provides an introduction to radiation safety. It defines radiation as energy emitted as particles or waves, and describes the electromagnetic spectrum. There are two types of radiation: non-ionizing and ionizing. Naturally occurring sources of radiation include bananas, the sun, and radioactive elements in the ground. Man-made sources include nuclear power plants, atomic bombs, medical equipment, and smoke detectors. Radiation contamination occurs when radioactive material is somewhere it shouldn't be. Exposure to radiation can increase cancer risks depending on the dose received. The Nigerian Nuclear Regulatory Authority regulates radiation exposure and safety in Nigeria.