Radiation Exposure of the Populations in the USSR Due to Medical Diagnostic Procedures

The levels of radiation exposure arising from X ray and radionuclide diagnostic examinations and received by patients at present attract much attention from specialists in radiation safety since medical radiation exposure is one of the most important man-made factors in the irradiation of the population. The estimation of radiation exposure of the population in the USSR presented in this paper was made on the basis of data on the frequency of 12 main types of X ray examination and the results obtained by absorbed dose measurement in a tissue-equivalent anthropomorphic phantom with simulation of real examination conditions. The estimation of irradiation due to radiopharmaceuticals was based on the use of 26 types of compounds in 320 laboratories. It was performed by the methods developed within the framework of the MIRD Committee (USA). The dose equivalents were determined in the active bone marrow, lungs, breast, thyroid, gonads and other organs (stomach, liver, spleen, etc.) and the effective dose equivalents were determined on this basis. The mean effective dose equivalent due to X ray diagnostic examinations is 1.4 mSv.y-1 (140 mrem.y-1) of which 26.9%, 55.4% and 17.7% are due to roentgenography, fluoroscopy and mass screening using photofluorography, respectively. The radionuclide diagnostic examinations add 3.2 x 10-2 mSv.y-1 (3.2 mrem.y-1). Irradiation for medical purposes approximately doubles the natural background, is comparable with the indoor irradiation and exceeds the radiation levels from other sources, such as the nuclear power industry, by a factor of tens of thousands.