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  2. Radiation exposure - Wikipedia

    en.wikipedia.org/wiki/Radiation_exposure

    Radiation exposure is a measure of the ionization of air due to ionizing radiation from photons. [1] It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. [1] As of 2007, "medical radiation exposure" was defined by the International Commission on Radiological Protection as ...

  3. Background radiation equivalent time - Wikipedia

    en.wikipedia.org/wiki/Background_radiation...

    Background radiation equivalent time (BRET) or background equivalent radiation time (BERT) is a unit of measurement of ionizing radiation dosage amounting to one day worth of average human exposure to background radiation. BRET units are used as a measure of low level radiation exposure. The health hazards of low doses of ionizing radiation are ...

  4. Orders of magnitude (radiation) - Wikipedia

    en.wikipedia.org/.../Orders_of_magnitude_(radiation)

    Light radiation sickness begins at about 50–100 rad (0.5–1 gray (Gy), 0.5–1 Sv, 50–100 rem, 50,000–100,000 mrem). The following table includes some dosages for comparison purposes, using millisieverts (mSv) (one thousandth of a sievert). The concept of radiation hormesis is relevant to this table – radiation hormesis is a hypothesis ...

  5. Roentgen equivalent man - Wikipedia

    en.wikipedia.org/wiki/Roentgen_equivalent_man

    0.01 Sv. The roentgen equivalent man (rem) [1][2] is a CGS unit of equivalent dose, effective dose, and committed dose, which are dose measures used to estimate potential health effects of low levels of ionizing radiation on the human body. Quantities measured in rem are designed to represent the stochastic biological risk of ionizing radiation ...

  6. Computed tomography dose index - Wikipedia

    en.wikipedia.org/wiki/Computed_tomography_dose_index

    The computed tomography dose index (CTDI) is a commonly used radiation exposure index in X-ray computed tomography (CT), first defined in 1981. [1][2] The unit of CTDI is the gray (Gy) and it can be used in conjunction with patient size to estimate the absorbed dose. The CTDI and absorbed dose may differ by more than a factor of two for small ...

  7. Deep-dose equivalent - Wikipedia

    en.wikipedia.org/wiki/Deep-dose_equivalent

    The Deep-dose equivalent (DDE) is a measure of external radiation exposure defined by US regulations. It is reported alongside eye and shallow dose equivalents on typical US dosimetry reports. It represents the dose equivalent at a tissue depth of 1 cm (1000 mg/cm2) due to external whole-body exposure to ionizing radiation.

  8. Roentgen (unit) - Wikipedia

    en.wikipedia.org/wiki/Roentgen_(unit)

    2.58 × 10−4 A ⋅ s / kg. The roentgen or röntgen (/ ˈrɛntɡən, - dʒən, ˈrʌnt -/; [2] symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays, and is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air (statcoulomb per kilogram).

  9. Radiant exposure - Wikipedia

    en.wikipedia.org/wiki/Radiant_exposure

    In radiometry, radiant exposure or fluence is the radiant energy received by a surface per unit area, or equivalently the irradiance of a surface, integrated over time of irradiation, and spectral exposure is the radiant exposure per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength.