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
Background radiation equivalent time Background radiation equivalent time Background Radiation Equivalent Time, or BRET, is a unit of measurement of ionizing radiation dosage. One BRET is the equivalent of one day worth of average human exposure to background radiation. The unit is also referred to as BERT (Background Equivalent Radiation Time). BRET units are used as a measure of low level radiation exposure. The health hazards of low doses of ionizing radiation are unknown and controversial, because the effects, mainly cancer and genetic damage, take many years to appear, and the incidence due to radiation exposure can't be statistically separated from the many other