Answer to Question #11199 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:


Four days ago I had 131I radioiodine ablation post thyroidectomy. My dose was 1.9 GBq. I have five children ages 8 months to 16 years.

How much longer is it not safe for me to hold my baby for long periods of time? Am I truly contaminating everything I touch? There are so many conflicting things I've read.

I stayed away from home for the first two days, have kept my distance, and stayed in a separate bed, but I am paranoid as to when I can feel safe around my children again. Please help!


Thank you for your questions. I'm sorry this has been so confusing for you, and I certainly understand how critical it is for you to know what you can and can't do and how to protect your children. You've done everything right so far.

There are two things that need to be considered in answering your question—one is the contamination issue and one is radiation exposure received by someone who comes close to you. Let's start with contamination.

You received some radioactive iodine (131I) and it actually does come out in sweat. Not a lot comes out, but items you touch could become contaminated. Where I work, we recommend precautions for contamination for the first two days after release from the hospital. This includes things like not sharing silverware, wiping down a TV remote control if you have used it, not preparing food for others, etc.

But contamination isn't the bigger issue when it comes to holding your children. The issue is the amount of radiation exposure they will receive when they are close to you. If today is four days after administration, your children being about 0.3 m from you for an hour is about the same as them receiving two to three chest x rays. If they stay 1 m or more away from you, the radiation exposure is minimal. If they are closer, the radiation exposure is higher.

Here are the recommendations from my organization for contact with others. These are based on radiation exposure considerations:

Restriction 1: For two days after release from the hospital, stay at least 1 m away from all others and stay in another home if you have children under the age of five. (You are already past this.)
Restriction 2: In homes where there are children under the age of five, for five more days after restriction 1, stay at least 1 m from those children. (If you are at day four, you have three more days of this.)
Restriction 3: In homes where there are children under the age of five, from day 7 until day 21, do not hug or hold them for more than 10 minutes a day. (If you are at day 4, you have 17 more days of this.)

Kelly Classic
Certified Medical Health Physicist

Answer posted on 20 April 2015. 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.