Effective doses from diagnostic medical exposures in Romania

The main objectives of this national study were to update the annual exposure of patients from diagnostic medical exposures ( X-ray examinations and nuclear medicine procedures) and to estimate the associated carcinogenic risk. Effective doses to about 3000 patients undergoing 20 most important types of X-ray examinations were derived from entrance surface dose or dose-area product measurements, carried out in 27 X-ray departments, and the appropriate conversion coefficients elaborated by the NRPB. The annual average effective dose per patient from all X-ray examinations performed in Romania was 1.37 mSv with the corresponding annual collective effective dose of 13,820 man Sv and the per capita annual effective dose of 0.55 mSv. Effective doses from diagnostic nuclear medicine procedures were calculated from the mean administered activities of the most frequently used radionuclides, multiplied by the appropriate dose conversion factors adopted by the ICRP. The annual average effective dose per patient from diagnostic nuclear medicine procedures was 16.2 mSv with 1124 man Sv as the annual collective effective dose and 0.05 mSv as the per capita annual effective dose. Diagnostic medical exposures, the highest man-made source of ionizing radiation, account for 16% of overall annual collective effective dose in Romania. The lifetime risk of radiation induced fatal cancers associated to the diagnostic medical exposures performed annually in Romania, assessed by applying the age- and sex-dependent nominal probability coefficients for individual organs and tissues to the collective equivalent organ doses, was of 611 cases from diagnostic radiology and of 44 cases from diagnostic nuclear medicine procedures. (authors)