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 1cm (1000mg/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 1cm 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

• Radioactivity

• Radiation poisoning

• Ionizing radiation

• Dosimetry

• Absorbed dose

• Total effective dose equivalent

• Collective dose

• Cumulative dose

• Committed dose equivalent

• Committed effective dose equivalent

References

• USNRC glossary

External links

• https://web.archive.org/web/20161221205248/http://www.wmsym.org/archives/2009/pdfs/9444.pdf - "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.