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 cancer, and death. Ionizing radiation is categorized by the nature of the particles or electromagnetic waves that create the ionizing effect. These have different ionization mechanisms, and may be grouped as directly or indirectly ionizing. Any charged massive particle can ionize atoms directly by fundamental interaction through the Coulomb force if it carries sufficient kinetic energy. This includes atomic nuclei, electrons, muons, charged pions, protons, and energetic charged nuclei stripped of their electrons. When moving at relativistic speeds these particles have enough kinetic energy to be ionizing, but relativistic speeds are not required. For example, a typical alpha particle is