During radiological and radionuclide diagnostic tests, the patient and staff may be affected by harmful factors of radiation nature: X-ray, γ- and β-radiation from external and internal (in case of incorporation of radionuclides) sources. Compliance with radiation safety requirements is a compulsory condition for radiological X-ray studies. In order to ensure radiation safety during such diagnostic tests, radiation protection measures for patients and staff included in the radiation safety system are carried out.
Radiation safety system in the use of ionizing radiation sources is a set of scientific approaches and practical measures aimed at ensuring sufficient protection of people from man-made radiation exposure, including its limitation by the established limits.
The administration of the institution is responsible for ensuring the safety of the use of radiation sources subordinated to it during medical exposures of patients, industrial exposures of staff and technogenic exposures of the population. Uncontrolled exposures from the natural background, nuclear tests, consequences of the Chernobyl accident, etc., are considered as external risks similar to transport, epidemic, household, etc. That is why their doses are not considered in the radiation protection of staff and the population, and if necessary are considered separately by the relevant state authorities.
19.1. INITIAL PREREQUISITES 19.1.1. Physical concepts and dosimetric quantities
Ionizing radiation is a stream of quanta or particles causing ionization of atoms and molecules of a substance, breaks of chemical bonds and formation of active free radicals. This leads to direct damage to biomolecules by radiation and indirect-chemical action of free radicals. Single-strand and double-strand breaks of deoxyribonucleic acid (DNA) are critical molecular damages to an organism.