The internal doses for workers or members of the public exposed to the intake of radioactive particulates can be estimated using bioassay data such as lung and body counter measurements, urine or faecal radioisotope concentration, etc.
The ICRP defines Committed effective dose, E(t) as the sum of the products of the committed organ or tissue equivalent doses and the appropriate tissue weighting factors WT, where t is the integration time in years following the intake.
[2] The ICRP further states "For internal exposure, committed effective doses are generally determined from an assessment of the intakes of radionuclides from bioassay measurements or other quantities (e.g., activity retained in the body or in daily excreta).
A whole body counter[5] has a low background arrangement with counting systems HPGe detectors are replacing detectors for measuring the low energy and high energy photons with appropriate electronic systems.
All current ICRP models, compiled in the OIR (ICRP134/137) data viewer,[6] can be represented by compartmental systems with constant coefficients.
If a person inhales instantaneously a quantity I, it is deposited directly in some compartments of the HRTM.
It is a function of Activity Median Aerodynamic Diameter (AMAD), which includes size, shape, density, anatomical and physiological parameters as well as various conditions of exposure.
A few computer codes have been developed to estimate intake and calculate internal dose using biassay data.
[7] Biokinetic modeling is widely used in internal dosimetry and to evaluate bioassay data.