The contribution of skin contamination dose to the total extremity dose of nuclear medicine staff: First results of an intensive survey

During nuclear medicine procedures technologists are exposed to high extremity doses as a result of manipulation of syringes and vials. These manipulations also involve a risk on contamination with liquids that have a relatively high specific activity. Even minor contaminations can lead to major extremity doses especially in the case of beta-emitters. This means that contamination survey followed by decontamination, where appropriate, is needed in routine practise. In this study contaminations were monitored during a long-term survey with a protocol based on fast identification, localisation and quantification. During the first 5 months of the survey 300 inspections were carried out among 10 technologists. Contamination was found in 28 (9%) cases (23 99mTc-labelled radiopharmaceuticals, 5 18FDG). All detected contaminations were highly localised with values ranging from 185Bq to 440 kBq. The skin dose rates were calculated using different reference data and methods. The use of the effective half-lives, the estimated exposure time and the reference data for dose rates resulted in a wide range of cumulated skin doses from 8 mSv to 33 mSv. The first results of this survey indicate that extremity doses resulting from contaminations can have a large contribution to the total extremity dose of nuclear medicine technologists.