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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 small area in ...
Displayed background gamma radiation level is 9.8 μR/h (0.82 mSv/a) This is very close to the world average background radiation of 0.87 mSv/a from cosmic and terrestrial sources. Cloud chambers used by early researchers first detected cosmic rays and other background radiation. They can be used to visualize the background radiation
Background radiation is from naturally radioactive materials and cosmic radiation from space. [5] People are exposed to this radiation from the environment continuously, with an annual dose of about 3 mSv. [5] Radon gas is a radioactive chemical element that is the largest source of background radiation, about 2mSv per year. [17]
The worldwide average background dose for a human being is about 3.5 mSv per year , mostly from cosmic radiation and natural isotopes in the earth. The largest single source of radiation exposure to the general public is naturally occurring radon gas, which comprises approximately 55% of the annual background dose.
Recognized effects of higher acute radiation doses are described in more detail in the article on radiation poisoning.Although the International System of Units (SI) defines the sievert (Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of millirems (mrem), where 1 mrem equals 1/1,000 of a rem and 1 rem equals 0.01 Sv.
Therapeutic doses of radiation therapy are often given and tolerated well even at higher doses to treat discrete, well-defined anatomical structures. The same dose given over a longer period of time is less likely to cause ARS. Dose thresholds are about 50% higher for dose rates of 20 rad/h, and even higher for lower dose rates. [4]
(for another definition of background radiation see Cosmic background radiation) Pages in category "Background radiation" The following 6 pages are in this category, out of 6 total.
Radiophobia refers only to a display of anxiety disproportionate to the actual quantity of radiation one is exposed to, with, in many cases, radiation exposure values equal to, or not much higher than, what individuals are naturally exposed to every day from background radiation. Anxiety following a response to an actual life-threatening level ...