The International Commission on Radiological Protection has recently recommended a supplementary dose limit of 2 mSv to the abdominal surface of a pregnant member of staff in order to provide protection to her fetus comparable to that in members of the public, whose annual limit is recommended to be 1 mSv.
In order to determine whether this apparent attenuation factor of 50% is appropriate for nursing and imaging staff exposed to nuclear medicine patients, estimates were made of the ratios of the maternal abdominal surface to fetal dose appropriately weighted for time, distance and dose rate.
Thermoluminescent dosimeter (TLD) measurements were made at various depths in an anthropomorphic phantom irradiated at different distances by a distributed source of either technetium-99m or iodine-131 in order to determine the corresponding attenuation factors at the average fetal midline depth.
Dose estimates were based on these factors and on published values of dose rate and exposure times for nursing and imaging staff at these distances from the patient.
Fetal doses to nursing staff caring for an adult 99mTc patient were estimated to vary from 86 muSv to 1.6 muSv, with the corresponding ratio of the abdominal surface to fetal dose varying from about 1.8 : 1 to 1.5 : 1 as the patient became less dependent on nursing care and the mean distance from the patient increased.
Mots-clés Pascal : Dosimétrie, Maladie professionnelle, Radiologue, Femelle, Homme, Gestation, Estimation, Foetus, Exploration radioisotopique, Technétium, Iode, Médecine travail
Mots-clés Pascal anglais : Dosimetry, Occupational disease, Radiologist, Female, Human, Pregnancy, Estimation, Fetus, Radionuclide study, Technetium, Iodine, Occupational medicine
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0555545
Code Inist : 002B30B01B. Création : 01/03/1996.