[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Volatility of I-131 NaI
Dear Gordon
Dr. Carol Marcus gave us a very interesting and important lesson on the
volatility of I-131 NaI.
However, for your specific scenario, the volatility is not the task of
first priority.
The first priority is to keep calm and cover the spill with absorbent pads
to contain liquid.
Close door and windows and notify everyone in the room that radioactive
liquid has been spilled;
Everyone in the room go the door and kick off their shoes with their feet,
steeping out of the room as their feet leave their shoes. Do not walk further!
Remove your gloves and shoes if they have been in contact with the spill and
leave them together with anything which could be contaminated by the spill.
Close the door.
Call for assistance. If no one can hear, one person only should walk no
further than is necessary to find someone to call a radiation expert and get
a Geiger counter. (The one left in the room may be contaminated.)
Using the Geiger counter, measure the radiation count rates all over the
bodies of those persons who were in the room, with particular attention to
the hands and feet.
Remove immediately any contaminated clothing and place it in a large plastic
bag or other container as dispose as radioactive waste.
Wash any contaminated skin with a mild soap and plenty of water; do not use
a hard brush, or abrasive soap. After washing, and measuring should be
repeated until no counts above background can be measured or until the
count rate does not change after three cycles off washing. Skin moisturizing
lotion should be applied
between washings, if available.
Ref.:
Practical Radiation Safety Manual - Manual on Therapeutic Uses of Iodine 131
IAEA PRSM, 1992
J. J. Rozental
josrozen@netmedia.net.il
Israel
At 01:53 PM 9/15/99 -0500, you wrote:
>At 11:13 AM 9/15/99 -0500, you wrote:
>>Does anyone have any information on the volatility of I-131 NaI. We are
>>updating our emergency response program and one scenario involves a spill
>>of an I-131 therapy dosage (100 - 200 mCi) in a patient room (either prior
>>to administration or by the patient vomiting
>>shortly after receiving the dose. Looking for an approximate % of the
>>original activity that would initially be airborne.
>>
>>Thanks for your help,
>>
>>Gordon Axt
>>University of Iowa - Health Protection Office
>>
>>It's not about doughs, its about crust. (sorry Bill, its the allergy
>>medication:)
>>
>>************************************************************************
>>The RADSAFE Frequently Asked Questions list, archives and subscription
>>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>>
>
>Dear Gordon:
>
>All commercially available preparations of NaI-131 are stabilized against
>volatility. If there was a spill and it was left untouched for 24 hours,
>the volatility factor over that time would be about 1x10exp-6. (They have
>been measured in multiple laboratories for all manufacturers and for Syncor,
>which stabilizes the CIS-US product, and they are roughly similar.) As a
>spill would be cleaned up within an hour, in all likelihood, the airborne
>emission would be much less than that.
>
>One of the ways in which the products are stabilized is by making the pH
>very basic. If the patient has swallowed the medicine and then vomits some
>of it up, volatility will depend, in part, on how much acid was in the
>stomach to neutralize the base. My own, rather extensive experience of
>patients vomiting is that they very, very rarely do this as soon as the dose
>is administered. They usually do it some hours later. At this point, all
>the I-131 has been absorbed and the I-131 concentrated by the stomach lining
>from the blood-borne I-131 is definitely acidic. However, how acidic
>varies. Hypothyroid patients (and thyroid cancer patients getting high
>doses of I-131 should all be hypothyroid) put out less acid that euthyroid
>ones, and so the short answer is that I don't know how much volatility there
>will be. Back in the years when NRC, for absurd reasons, forbid Syncor to
>stabilize its NaI-131, I measured the airborne losses from two such doses at
>10% and 16%. I then went on the warpath and demanded that Syncor be
>permitted to stabilize preparations, charging that NRC was a bigger danger
>to public health and safety than all of nuclear medicine combined. I
>finally threatened Admiral Carr (then Chairman) that I would go to the
>Washington Post and the wire services to expose him if he did not relent.
>He did relent, and this was one of the issues that led to the "Radiopharmacy
>Rule". It was incredible to me at the time that the NRC, charged with
>protecting public health and safety, could insist on continuing to forbid
>Syncor from stabilizing its I-131 EVEN AFTER IT FOUND OUT HOW DANGEROUS THIS
>WAS. This was one of the issues that indelibly defined to me the
>intellectual level at which the NRC performs. The people at NRC responsible
>for this are still very actively involved in the "Medical" Program. By the
>way, I-131 contamination at a very low level was measured in my
>technologist's thyroid after administration of an unstabilized dose of
>NaI-131. We never had a spill, and the patients, if they vomited at all,
>vomited in the toilet so that there was no problem with airborne emissions.
>My tech took perchlorate, to help decrease further I-131 uptake, and I did
>not use Syncor's I-131 again until the pharmacists were stabilizing it.
>
>When the EPA was working on the radionuclide NESHAPs, I got a call from its
>subcontractor asking about the volatility factors of I-131 from belching and
>farting! I didn't know then, don't know now, and one of the best coups I
>ever pulled was exempting I-131 after it had been administered to patients
>from the radionuclide NESHAPS, on the basis that it was uncontrollable by
>Authorized Users.
>
>In summary, I don't think that airborne emissions from NaI-131 use in
>patients is a problem. In the event of a spill, it would be prudent for
>those who clean it up to take some SSKI first, and I always keep some handy
>for emergencies. I also send over a fresh bottle of SSKI from time to time
>to my RSO, in case I am not around during an accident. NaI-131 used for
>radiolabeling is NOT stabilized, and so it could be more of an issue in
>research laboratories than on Nuclear Medicine services. If there are
>laboratories around that use significant quantities of NaI-131 or NaI-125,
>it would probably be enough to keep some SSKI around those labs. As it is
>available only by prescription, get one of your docs to write as many
>prescriptions as are necessary, and instruct that anyone using it after an
>accident should report to Nuclear Medicine for a thyroid uptake. As thyroid
>uptake probes are not calibrated for I-131 or I-125 for any clinical
>purpose, you might invest in some standards to do so in case of a worker
>contamination situation. At Harbor-UCLA, the RSO and Nuclear Medicine have
>uptake probes, and whenever the RSO calibrates his probe, he sends the
>sources over to Nuclear Medicine for a calibration as well.
>
>Ciao, Carol
>
><csmarcus@ucla.edu>
>
>************************************************************************
>The RADSAFE Frequently Asked Questions list, archives and subscription
>information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
>
>
jjrozental
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html