Ionizing radiation fields. Natural sources include the sun, lightning and supernova explosions. Artificial sources include nuclear reactors, particle accelerators, and x-ray tubes. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) itemized types of human exposures. The International Commission on Radiological Protection manages the International System of Radiological Protection, which sets recommended limits for dose uptake. Background radiation comes from both natural and man-made sources. The global average exposure of humans to ionizing radiation is about 3 mSv (0.3 rem) per year, 80% of which comes from nature. The remaining 20% results from exposure to man-made radiation sources, primarily
Ionizing radiation found in space can also cause single-event upsets in digital circuits. The electrical effects of ionizing radiation are exploited in gas-filled radiation detectors, e.g. the Geiger-Muller counter or the ion chamber. In general, ionizing radiation is harmful and potentially lethal to living beings but some types have medical applications in radiation therapy for the treatment of cancer and thyrotoxicosis. Most adverse health effects of exposure to ionizing radiation may be grouped in two general categories: The most common impact is stochastic induction of cancer with a latent period of years or decades after exposure. For example, ionizing radiation is the