Evaluation of the internal contamination risk for isotope laboratory workers

The investigation covered 484 workers. Altogether 1787 determinations have been made, in this - 1648 internal contaminations and 139 contaminations of air, hand skin and working surfaces. The internal contaminations (22% of results) resulted mainly from deviation from radiological protection rules and were reduced by certain changes. Those were tritium contaminations (application of tritium radioluminescence dyes) and 125,131J. The highest levels of which were 20 mSv and 0.25% ALI respectively. The results of 238Pu air contamination measurements indicates that the dust arising during the production of smoke detectors (with 238PuO2 sources) probably has no respirable fraction properties, what confines its absorption in lower parts of the respiratory tract. It has been demonstrated that in Poland is no need of a central system of permanent internal contamination control. (author)