Background radiation equivalent time BRET value corresponding to a dose of radiation is the number of days of average background dose it is equivalent to. It is calculated from the equivalent dose in sieverts by dividing by the average annual background radiation dose in Sv, and multiplying by 365: The definition of the BRET unit is apparently unstandardized, and depends on what value is used for the average annual background radiation dose, which varies greatly across time and location. The 2000 UNSCEAR estimate for worldwide average natural background radiation dose is 2.4 mSv (240 mrem), with a range from 1 to 13 mSv. A
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