Answer to Question #8690 Submitted to "Ask the Experts"

Category: Nuclear Medicine Patient Issues — Therapeutic Nuclear Medicine

The following question was answered by an expert in the appropriate field:


I was treated with 444 MBq of 131I for hyperthyroidism two days ago. I have followed the safety precautions to minimize exposure to others. However, I have two sons: 12 months and five years old. I'm afraid to touch any surface they may come in contact with, like door knobs, chairs, refrigerator door, and even the floor since the baby crawls. I'm supposed to maintain a distance for three days. What happens after the three days? I understand that the half-life is eight days and I'll be "radioactive" until after 80 days. Are there any other precautions that I need to take?


I can understand your concern regarding keeping the exposure to your children as low as possible.

My facility has done surveys in people's homes after radioiodine therapy and mainly found contamination (1) on the person's pillow case—because your head sweats and there is iodine in the sweat, (2) on the telephone from the sweat from people's hands, and (3) on the bathroom sink. People also lose hair when they brush it or just through the day, so daily vacuuming for the first week or so will keep the floor clean for the children.

Frequent hand washing is another good practice to keep your house free of contamination. Washing your hands before preparing food is especially important for at least two weeks. I would recommend not sharing food or drink with the children for the first two weeks.

I would also recommend not letting the children sleep with you for two months.

I think if you follow these suggestions, you will keep their exposure low and do not have to be concerned about their possibly ingesting any radioactive iodine.

Marcia Hartman, MS

Answer posted on 8 December 2009. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.