Background：In general, medical staff dealing with nuclear medicine should be entirely safe in their professional environment. Nevertheless, their exposure to radioactive iodine seems to be partially uncontrolled while they perform their duties, namely while administering iodine in the form of tablets or solutions or while taking care of the patients already treated with the isotope.
Purpose: To verify such a hypothesis, develop a simple method for internal exposure monitoring，131I activity measurements in the thyroids of the personnel employed at the three hospitals of Gansu province grade a hospital nuclear medicine. Mastered the internal exposure of nuclear medical personnel.
Methods: Choosing 20 employees of the department of three hospitals of gansu province grade a hospital nuclear medicine, which corresponds to circa 100% of all of the all the staff of the nuclear medicine department who carry out iodine therapy. Automatic packaging and drug delivery staffs were 6, manual packaging and drug delivery staffs were 14. According to the rules of the judgment principles proposed in IAEA safety guidelines, An InSpector 1000 portable spectrometer and its supporting software served as the basic research instrument. In four out of twenty examined staff members. The sitting position was adopted with NaI portable spectrometer. The measurement time was 120s.
Result: Among the manual packaging and drug delivery staffs was 4 (20.0%) detected 131I in the thyroid, with activity range of 27.6-1030.3Bq. Automatic packaging and drug delivery staffs were not detected.
Conclusions: The highest activities in thyroids were detected for the manual packaging and drug delivery staffs, Automatic packaging and drug delivery staffs were not detected. The dose of some workers is high, so the prevention and control of pollution in nuclear medicine discipline needs to be strengthened urgently.