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
Equivalent dose is a dose quantity '' H '' representing the stochastic health effects of low levels of ionizing radiation on the human body which represents the probability of radiation-induced cancer and genetic damage. It is derived from the ph ...
at a tissue depth of 1 cm (1000 mg/cm2) due to external whole-body exposure to
ionizing radiation.
Dose due to external radiation tends to decrease with depth because of the shielding effects of outer tissues. The reference depth of 1 cm essentially discounts alpha and beta radiation that are easily shielded by the skin, clothing, and bone surface, while taking minimal credit for any self-shielding from the more penetrating gamma rays. This makes the deep-dose equivalent a conservative measure of internal organ exposure to external radiation, while eye and skin exposure to external radiation must be accounted differently. Deep-dose equivalent does include any contribution from internal contamination.
See also
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Radioactivity
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Radiation poisoning
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Ionizing radiation
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Dosimetry Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested ...
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Absorbed dose
Absorbed dose is a dose quantity which is the measure of the energy deposited in matter by ionizing radiation per unit mass. Absorbed dose is used in the calculation of dose uptake in living tissue in both radiation protection (reduction of harmf ...
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Total effective dose equivalent
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Collective dose The collective effective dose, dose quantity S, is calculated as the sum of all individual effective doses over the time period or during the operation being considered due to ionizing radiation. It can be used to estimate the total health effects ...
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Cumulative dose
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Committed dose equivalent
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Committed effective dose equivalent
References
USNRC glossary
External links
- "The confusing world of radiation dosimetry" - M.A. Boyd, 2009, U.S. Environmental Protection Agency. An account of chronological differences between USA and ICRP dosimetry systems.
Radioactivity
Radiation health effects
Equivalent units
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