Total Effective Dose Equivalent (TEDE)

Total Effective Dose Equivalent (TEDE)

The Total Effective Dose Equivalent (TEDE) is a measure used in radiation protection to quantify the risk of exposure to ionizing radiation. It is a comprehensive dose quantity that accounts for both external and internal sources of radiation exposure. TEDE is expressed in sieverts (Sv), which is the SI unit for dose equivalent.

Definition

TEDE is defined as the sum of the effective dose equivalent from external radiation sources and the committed effective dose equivalent from internal sources. Mathematically, it can be expressed as:

\[ \text{TEDE} = \text{E}_{\text{external}} + \text{E}_{\text{internal}} \]

where: - \(\text{E}_{\text{external}}\) is the effective dose equivalent from external radiation sources. - \(\text{E}_{\text{internal}}\) is the committed effective dose equivalent from internal radiation sources.

Components

External Dose

The external dose component of TEDE is the effective dose equivalent received from radiation sources outside the body. This includes exposure to gamma rays, X-rays, and other forms of ionizing radiation that penetrate the body from the environment.

Internal Dose

The internal dose component is the committed effective dose equivalent, which accounts for radioactive materials that have been ingested, inhaled, or otherwise entered the body. This dose is calculated over a period of 50 years for adults and up to age 70 for children, reflecting the long-term risk of internal contamination.

Calculation

The calculation of TEDE involves assessing both the external and internal doses using dosimetric models and measurements. For external doses, personal dosimeters such as thermoluminescent dosimeters (TLDs) or electronic personal dosimeters are commonly used. Internal doses are assessed using bioassay data, whole-body counting, and modeling of radionuclide intake.

Applications

TEDE is used in various fields, including:

- Radiation Protection: To ensure that occupational and public exposures to radiation are within safe limits. - Nuclear Medicine: To evaluate the doses received by patients undergoing diagnostic or therapeutic procedures involving radioactive materials. - Environmental Monitoring: To assess the impact of radioactive releases on the environment and public health.

Regulatory Standards

Regulatory bodies such as the International Commission on Radiological Protection (ICRP) and the United States Nuclear Regulatory Commission (NRC) provide guidelines and limits for TEDE to protect workers and the public from harmful effects of radiation.

Also see

- Radiation dose - Effective dose - Sievert - Radiation protection - Ionizing radiation