<unk> , or BRET, is a unit of measurement of ionizing radiation dosage. One BRET is the<unk>  of one day worth of average human exposure to<unk>  radiation. The unit is also referred to as BERT<unk><unk>  Radiation<unk> . 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 causes of these diseases. The purpose of the BRET measure is to allow a low level dose to be easily compared with a universal yardstick: the average dose of<unk>  radiation, mostly from natural sources, that every human unavoidably receives during daily life.<unk>  radiation level is widely used in radiological health fields as a standard for setting exposure limits. Presumably, a dose of radiation which is<unk>  to what a person would receive in a few days of ordinary life will not increase his rate of disease measurably.
Background radiation equivalent time
Epidemiology data for low-linear energy transfer radiation
Deemed status
Safety of electronic cigarettes
Dose profile
Reference dose
Risk of mortality
Survival rate