Background radiation equivalent time small area in India as high as 30 mSv (3 rem). Using the 2.4 mSv value each BRET unit equals 6.6 μSv. BRET values for diagnostic radiography procedures range from 2 BRET for a dental x-ray to around 400 for a barium enema study. 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
Ionizing radiation radiation is always ionizing, but only extreme-ultraviolet radiation can be considered ionizing under all definitions. As noted, the biological effect of ionizing radiation on cells somewhat resembles that of a broader spectrum of molecularly damaging radiation, which overlaps ionizing radiation and extends beyond, to somewhat lower energies into all regions of UV and sometimes visible light in some systems (such as photosynthetic systems in leaves). Although DNA is always susceptible to damage by ionizing radiation, the DNA molecule may also be damaged by radiation with enough energy to excite certain molecular bonds to form thymine dimers. This energy may be