Incorporation risks for workers in pet centres

The incorporation risks for workers in PET centres were assessed in order to determine whether incorporation monitoring on a regular basis is necessary. The procedures involving radioactive substances were recorded and tested for the risk of incorporation by workers. For 20 workers involved in these procedures, a total of 108 measurements of whole-body activity were performed. From these, incorporated activities and resulting effective doses were computed conservatively. Whole-body activity above the detection limit (50 Bq) was measured in 38 of 79 cases, above 1500 Bq in only 4 cases. Estimated yearly doses exceeded 50 mu Sv in only 10 of 79 cases and never exceeded 1500 mu Sv. internal exposure from routine procedures in a PET centre is rather low. The estimated doses do not warrant the necessity of incorporation monitoring on a regular basis. However, availability of a whole-body measurement facility within 24 h of an incident is recommended as well as monitoring of airborne activity during transport and handling of gaseous radioactivity.