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
International Commission on Non-Ionizing Radiation Protection medicine, physics and dosimetry and optical radiation. Its members are scientists employed typically by universities or radiation protection agencies. They do not represent their country of origin, nor their institute and can not be employed by commercial companies. ICNIRP is widely connected to a large community working on non-ionizing radiation protection around the world. Its conferences and workshops are widely attended. ICNIRP presents its draft guidelines online for public review and comment before publication. It has ties to IRPA and is formally recognized by the World Health Organization (WHO) and the International Labour Office (ILO) as partners in the field