ANALYSIS OF RADIATION-DOSES RECEIVED BY THE PUBLIC FROM I-131 TREATMENT OF THYROTOXIC OUTPATIENTS

Radiation doses to the family and general public from I-131 therapy of outpatients were assessed for comparison with the 1990 International Commission on Radiation Protection (ICRP) dose limits. Doses to family members of such patients, measured by previous workers, were converte d to show that on average 5.6 +/- 3.7 muSv MBq-1 is received by the sp ouse and 1.5 +/- 0.87 muSv MBq-1 by other family members. It was deduc ed that the average dose to the spouse (D muSv MBq-1) when couples sle ep apart for T days after administration is given by: D = 2.528 + 3.07 2e-0.11T if an effective half-life, T(eff), of 6.35 days is used. The cumulative effect of repeated treatments should be considered and in v iew of ALARA it is recommended that couples sleep apart for at least 1 4 days after each administration, even if this is below limits permitt ed by authorities. The dose to a pregnant colleague or family member o ther than the wife should be below 2 mSv if the total administered act ivity is not more than 600 MBq. If the wife is pregnant, couples shoul d sleep apart for at least 30 days after administration.