Airborne concentration of I-131 in a nuclear medicine laboratory.

This study measures the airborne radioactivity during the handling of millicurie quantities of I-131 in the liquid and capsule form. The data indicate there is significant airborne activity when bottles containing 100--145 mCi of liquid I-131 are opened, and that the Nuclear Regulatory Commission level for airborne activity of I-131 in restricted areas (9 X 10(-9) muCi/ml) is exceeded. However, the airborne activity of I-131 is below the Nuclear Regulatory Commission level for restricted areas when 100-mCi quantities of I-131 in the capsule form are used, or during handling of liquid I-131 in the 20- to 30-mCi range. Thyroid counting is a better method than film badge for monitoring the personnel.