Ionizing radiation a cancer per dose model to assert that such activities cause several hundred cases of cancer per year, an application of the widely accepted Linear no-threshold model (LNT). The International Commission on Radiological Protection recommends limiting artificial irradiation to the public to an average of 1 mSv (0.001 Sv) of effective dose per year, not including medical and occupational exposures. In a nuclear war, gamma rays from both the initial weapon explosion and fallout would be the sources of radiation exposure. Massive particles are a concern for astronauts outside the earth's magnetic field who would receive solar particles from solar
Ionizing radiation ionizing, but moves at about 5% c, and an electron with 33 eV (enough to ionize) moves at about 1% c. The first two ionizing sources to be recognized were given special names used today: Helium nuclei ejected from atomic nuclei are called alpha particles, and electrons ejected usually (but not always) at relativistic speeds, are called beta particles. Natural cosmic rays are made up primarily of relativistic protons but also include heavier atomic nuclei like helium ions and HZE ions. In the atmosphere such particles are often stopped by air molecules, and this produces short-lived charged pions, which soon