ABSTRACT
Radiation enters organisms in different ways depending on its energy. The radiation displaces peripheral electrons from stable atoms creating ‘cations’ or else generates one or more atoms with ‘free’ electrons – such atoms are called ‘free radicals’. Nuclear incidents have contributed to better understanding of the effects of radiation and their impact on the environment. The clinical picture is typically consistent with the known ‘acute irradiation syndrome’. The haematological signs develop during this phase and can result in medullary aplasia. The body surface irradiated must be assessed: irradiation of more than 18% of the total body surface is considered as ‘whole-body irradiation’. Internal irradiation following internal contamination is the result of the ingestion of or the penetration into the body by radionuclides. External irradiation is often associated with internal irradiation. Irradiation of small volumes of tissue is better tolerated than irradiation of the entire human body. Distribution of the dose within the body is also important.
