[Radiotoxicology].

Radiotoxicology is a science aiming firstly to estimate the biological effects induced by radiation in workers and general population after internal contamination of radionuclides, secondly evaluate the risk on health. After internal contamination, the analysis of biokinetics of radioactive compounds allow to understand their behaviour in the body. Those complex processes describe routes of radionuclide intake, direct blood uptake or transfer of soluble form to blood from deposit area, urine and fecal excretions, distribution and retention of radionuclides in different target organs. These processes are modelled to establish mathematical calculations. Data obtained are important to the interpretation of bioassay measurement for initial activity deposit expressed in becquerel (Bq: transformation.s-1) and committed effective dose calculation, expressed in sievert (Sv). This committed effective dose corresponds to the absorbed dose expressed in gray (Gy), weighted by a radiation weighting factor related to the quality of radiation and a tissue weighting factor which represents the contribution of the target organ to the total detriment due to effects induced by uniform irradiation of the whole body. This committed effective dose is a specific parameter for risk assessment which characterizes the radiotoxicology as a special part of toxicology.