Committed Dose
When radionuclides are taken into the body, the resulting dose is received throughout the period of time during which they remain in the body. The total dose delivered during this period of time is referred to as the committed dose and is calculated as a specified time integral of the rate of receipt of the dose.
The committed equivalent dose is defined as:
\[ H_T(\tau) = \int_{t_0}^{t_0 + \tau} H_T(t) \, dt \]
Where:
- t0 is the time of intake,
- \( \tau \) is the integration time, which is 50 years for workers and adult members of the general public, and 70 years for children.
The committed effective dose is given by:
\[ E = \sum_T w_T H_T(\tau) \]
Where:
- HT(τ) is the committed equivalent dose in organ or tissue \( T \),
- wT is the tissue weighting factor for organ or tissue \( T \), and
- The sum is performed over all relevant organs or tissues that are sensitive to stochastic effects.
The committed dose quantities are essential in evaluating the long-term health risks associated with radionuclide exposure. These quantities help in assessing the total radiation dose over time from radionuclides that remain in the body.
Summary of Radiation Protection Quantities and Units
| Quantity | Unit | Description |
|---|---|---|
| Mean Organ Dose (DT) | Gray (Gy) = J/kg | Measures the energy imparted to a specific organ or tissue from radiation. |
| Equivalent Dose (HT) | Sievert (Sv) | Accounts for the biological effectiveness of different types of radiation. |
| Effective Dose (E) | Sievert (Sv) | Summation of the equivalent doses to various organs, weighted by tissue sensitivity. |
| Ambient Dose Equivalent (HA) | Sievert (Sv) | Measures the radiation dose in the environment. |
| Personal Dose Equivalent (HP) | Sievert (Sv) | Monitors the dose received by an individual from external radiation sources. |