I have searched long and hard for information regarding safety after taking I-131 when around children. I finally looked hard enough to find some great recommendations, solidly based on science. And some mathematical formulas for calculating the dose of radiation I am emitting at any given moment after I receive my pill. I've received criticism from other cancer patients for choosing to stay away from home so long after my treatment and prior scans. That criticism makes it hard for me to stay away, because, believe me, I would prefer to be at home with my kids if I really believed it to be safe. I also think that criticism stems from the lackadaisical approach to nuclear safety our country has recently taken in order to eliminate in-patient management of patients post-radioactive iodine intake.
It is important that someone on this vast Internet speak out about what is truly safe for others. Because going home and holding your children 24 hours after you receive I-131 is most certainly, scientifically,
NOT safe.
For a treatment dose of 33 millicuries or greater, the recommendations are:
Try to minimize time spent with young children. Children under 12 must stay in a separate residence for the first 7 days. Maintain a 1 meter distance from children under 12 for 7 days. Eliminate holding children under 12 for 14 days. Minimize holding children under 12 for 21 days.
For scan doses 3-10 millicuries, the recommendations are:
Try to minimize time spent with young children. Children under 12 must stay in a separate residence for the first 3 days. Maintain a 1 meter distance from children under 12 for 5 days. Eliminate holding children under 12 for 5 days. Minimize holding children under 12 for 7-14 days.
These recommendation are culled from the
University Health Network and the
Health Physics Society. The
U.S. Nuclear Regulatory Commission puts the annual dose limit for minors (under 21 years of age) at 0.5 mrems of total effective dose. Adults in the general population can receive up to 1 mrem annually. Radioisotope sodium iodide 131 emits
2.3 mrem/hr/mCi at 30 cm, meaning my 5 mCi of I-131 is emitting 11.5 mrem/hr at 30 centimeters from my thyroid.
In plain English, this means that you hugging me for 1 minute means you receive 0.2 mrem of radiation. That's almost half of the
ANNUAL dose limit for a child. That holds true for 2-3 days after I receive a scan dose of 5 mCi (as I did today at 12:30 p.m.). 1/1,000th of my scan dose could mean thyroid cancer for my child. That means my scan dose must be divided in half many, many times by elimination through my urine before it is safe for me to hold my child. As a co-sleeping mother, that alarms me. Enough to keep me away from my children for days. To strictly adhere to the guidelines I've been given - guidelines that are specific to my living situation, my dose, and my known elimination rate of I-131 as calculated by prior uptake scans at specific time lapses from previous doses.
One last note:
the half-life (rate at which a substance is eliminated by half by the human body) of I-131 is 8.1 days. Not until two half-lives of I-131 will I be considered "safe" to have frequent, close contact with my children (holding them or sleeping with them). This means 24.3 days. So by mid-January, I can resume normal life. Until then, I do have to worry about exposing my children - and others - to dangerous radiation.
The last thing I want to do is cause one of my offspring to suffer in this same way.
