FW: Tritium Therapy & Beer Drinking

["Carbaugh, Eugene H" <gene.carbaugh@pnl.gov>]

Sorry guys, I fell into the trap of starting a paragraph with "from" and the
server chopped off the last half of my message - which was actually the most
practical part.  Thanks to Vince King for reading it and noting that something
seemed missing (he knows me too well!)  The modified-for-completeness message is
shown below (I hope).
	Gene Carbaugh
	pnl.gov


OK.  I wasn't going to enter into this discussion but it's taken enough twists
and turns that I decided I'd add some valid science to all the anecdotal stuff
going on.  The therapy for dose reduction for a tritium intake is basically to
accelerate the body water turnover but diuretics and forced fluid consumption.
I think we all agree on this, but you can check NCRP-65, Management of Persons
Accidentally Contaminated with Radionuclides, or the "Guidebook for the
Treatment of Accidental Internal Radionuclide Contamination of Workers,"
(Radiation Protection Dosimetry, Vol 41:1, 1992) - both of which I recommend to
be on your bookshelf if you deal with this issue.  BTW, both also deal with
sodium bicarbonate as applied to uranium - it's intravenous infusion to form a
uranium carbonate complex which is rapidly excreted in urine.  Neither of these
have anything to do with chelation which is also addressed in these two
publications.

So if forced fluids accomplishes dilution (which it does), most any fluid would
work - water, juices, beer, tea, coffee, etc.  Some work better than others,
some have side effects.  The real issue is how much and how long.  If you're
going to half the dose from a tritium intake by forcing fluids you are going to
have to double the clearance rate - not just for one day but sustain it for at
least a 3 or 4 weeks (remember the 10 day effective half-life).  That is the
hard part.  Drinking a few beers, etc, for a couple of days just isn't going to
accomplish much, other than giving the drinker a psychological idea that doing
something is better than nothing.

Now a practical standpoint, sustained forced fluids or diuretics is a medical
therapy that requires monitoring of the electrolytic balance.  Thus, get your
medical people involved.  A very nice case study can be found in "Accidental
Intake of Tritiated Water:  A Report of Two Cases," by DC Lloyd, AA Edwards, and
JS Prosser of the British NRPB (Radiation Protection Dosimetry, 15:3 pp 191-196,
1986).  The principal case showed that in the first 4 days following the intake,
when the advice was "to drink more," the worker accelerated the effective
half-life to 6.4 days.  Under hospitalization and diuresis therapy (days 4 to 8)
the  half-life accelerated to 2.7 days.  After discharge from the hospital it
slowed to 10 days.  The net effect?  If no therapy had been administered, the
estimated dose was 80 rem (half-life of 10 days).  If a sustained drinking
regime resulted in 6.4 day half-life, the dose would have been 55 rem.  Had
hospital diuresis therapy been started immediately the dose could have been
reduced to 41 rem.   The final dose estimate for the actual case was 47 rem and
the case was considered at the borderline of justified forced diuresis (in view
of the hazards of electrolye imbalance).  The key point for me in this was that
a practical dose reduction of maybe 30% might be accomplished by an individual
truly committed to fluid consumption, whereas a 50% or better reduction might be
accomplished by prompt medical therapy.  

Sorry to interject the serious response amid all the fluff.  Now I'll retire to
my wine cellar and deal with my own dilution issues.

Gene Carbaugh, CHP
Internal Dosimetry
Pacific Northwest National Laboratory
Richland, WA 

gene.carbaugh@pnl.gov

************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html