[Evaluation of the risk of internal contamination of persons working in isotope laboratories].

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 through certain changes. Those were tritium contaminations (application of tritium radioluminiscence dyes) and 125--and 131-iodine radioisotopes (in nuclear medicine laboratories) the highest levels of which were 20 mSv and 0.25% ALI respectively. The results of 238Pu air contamination measurements have indicates that the dust arising during the production of smoke detectors (with 238PuO2 sources) probably has no respirable fraction properties, which confines its absorption in lower segments of the respiratory tract. It has been demonstrated that in Poland there is no need of constructing a permanent central system of internal contamination control.