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The increase in background radiation due to these tests peaked in 1963 at about 0.15 mSv per year worldwide, or about 7% of average background dose from all sources. The Limited Test Ban Treaty of 1963 prohibited above-ground tests, thus by the year 2000 the worldwide dose from these tests has decreased to only 0.005 mSv per year.
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 ...
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 magnitude of the energy of cosmic ray flux in interstellar space is very comparable to that of other deep space energies: cosmic ray energy density averages about one electron-volt per cubic centimetre of interstellar space, or ≈1 eV/cm 3, which is comparable to the energy density of visible starlight at 0.3 eV/cm 3, the galactic magnetic ...
For purposes of comparison, the world average dose rate from naturally occurring sources of background radiation is 2.4 mSv per year, equal for practical purposes in this application to 2.4 mGy per year. [182] While there is some variation, most people (99%) received less than 7 mSv per year as background radiation. [186]
The background rate for natural radiation varies considerably with location, being as low as 1.5 mSv/a (1.5 mSv per year) in some areas and over 100 mSv/a in others. The highest level of purely natural radiation recorded on the Earth's surface is 90 μGy/h (0.8 Gy/a) on a Brazilian black beach composed of monazite . [ 28 ]
For comparison, the average 'background' dose of natural radiation received by a person per day, based on 2000 UNSCEAR estimate, makes BRET 6.6 μSv (660 μrem). However local exposures vary, with the yearly average in the US being around 3.6 mSv (360 mrem), [ 6 ] and in a small area in India as high as 30 mSv (3 rem).
(for another definition of background radiation see Cosmic background radiation) Pages in category "Background radiation"