MEASUREMENT OF EXTREMITY DOSES OF NUCLEAR ENERGY WORKER BY USING RING DOSIMETER

Finger doses can serve as a guide to suggest any needed modification in work practice to minimise radiation doses to the extremities. In the present study, radiation doses at the base of the middle finger of both hands of 20 nuclear energy workers handling Tc-99m-labelled compounds,I-125 and(131)I during various diagnostic and therapeutic procedures in nuclear medicine were measured. The laboratory assessments were carried out by means of thermoluminescence ring dosimetry in Health Physics Division, Atomic Energy Center, Dhaka. The recorded extremity doses were then compared to their routinely monitored whole-body doses. The average annual finger doses recorded in this study were found to be 10.7 +/- 8.2 and 12.7 +/- 12.9 mSv, respectively, for the left- and right-hand fingers, which are at least 12-fold higher than the average whole-body dose. There was, however, no extreme case found of health hazard to the workers' hand, which exceeds maximum dose limit 500 mSv/year given by the International Commission on Radiological Protection. On comparing the average annual finger doses at different labs, significantly higher average dose was recorded at isotope-dispensing lab (19.6 +/- 12.6 mSv/year) and then followed by gamma camera lab (13.2 +/- 12.1 mSv/year) and radioimmunoassay lab (7.0 +/- 5.5 mSv/year). These observations are fairly in good agreement with the reported results. The observations of the present study, therefore, may be implemented for the betterment of safety for the occupational workers in nuclear medicine facilities.