Answer to Question #12930 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:

Q

I received 504 MBq of 131I treatment for my thyroid. I was told to avoid certain things for three days. I did not understand before my treatment that it has serious consequences. I have two young grandchildren. Here are my questions:

  1. After taking the radioiodine pill, how long will it stay in my body to expose others? For example, when can I hug my grandchildren? How long will it take for my body to be 100% clear of the radiation and not harm others?  
  2. I am staying in a separate room at my home. How long will the radiation stay in the room in which I am sleeping? If I should not use bleach for cleaning, is there a special material I can use? How can I measure the radiation levels in my house?
A

The answer to your first question is as follows: The radiation in your body will not harm others and you can treat it as if it's a bad cold. I would say give it a week, before you hug or kiss the children, so to make sure they don't catch the "cold."

With regard to your second question having to do with sleep arrangements, the general instruction is to sleep alone for a week. As far as cleaning, radiation is not a type of bacteria or virus, so bleach won't help remove it. You can simply use the regular cleaning products you use for the various household cleaning goals and release the wastewater to the sewer system, where the 131I will be greatly diluted and will decay away in relatively short order.

As long as you follow the general personal hygiene instructions provided to you by your physician, such as double flush toilet and wash hands for 20 seconds, you should not need to worry about the radiation level in your house. Again, treat the situation as if you have a "bad cold" and there will be no need to measure the number of cold viruses in your house in order to make sure everyone in the house is safe.  

I hope my responses relieve your concerns regarding the 131I therapy you have received. 

Carol Wen, CHP

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 5 June 2019. 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.