Re: "Normal" concentration of tritium in urine

["Schoenhofer" <schoenho@via.at>]

Schoenhofer
Habichergasse 31/7
A-1160 Wien
AUSTRIA
Tel./Fax: +43-1-4955308
Mobiltel.: +43-664-3380333
e-mail: schoenho@via.at

You wrote:

-Andy Hull <hull@mail.sep.bnl.gov>
> An: Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Betreff: Re: "Normal" concentration of tritium in urine
> Datum: Montag, 20. Oktober 1997 21:46
> 
> Rick,
> While I'm not sure what you are looking for, I assume that the "normal"
> concentration of tritium in urine should be comparable to that of
> precipitation(unless influenced by some proximate local source.
> since the recent concentrations of tritium in precipitation are much less
> than 100 pCi/l, they are not detectable by straightforward LSC analysis.
The
> current "normal" concentration would be far lower than could be detected
by
> standard LSC analysis, but would require prior enrichment.

The concentration should be close to the concentration in precipitation,
concentration in drinking water (which normally is about the same) amd in
food. In the northern hemisphere the tritium concentration in precipitation
is in the range of 2 Bq/l (54 pCi/l), in the southern hemisphere it is much
lower. There have much more nuclear atmospheric tests with much higher
yields been conducted in the northern hemisphere and there is very little
exchange between the southern and the northern atmosphere. We measure the
current environmental levels of tritium in precipitation, surface and
ground waters straightforward without enrichment with our ultra low-level
liquid scintillation spectrometers ("Quantulus" from EG and G Ortec -
Wallac) which gives a LLD of about 0.7 Bq/l (based on 500 min count and 3
sigma of the background), without enrichment. 

The last atmospheric nuclear bomb tests have been conducted in China in the
beginning of the eighties. France finished 1974 (by the way in the Southern
hemisphere), USA and Sovjetunion in 1962. Since 1964 the tritium (and the
C-14) concentrations in the atmosphere and in precipitation have declined
steadily.

In areas where groundwater is affected by tritium discharges concentration
will be much higher, but this I do not regard as "background" values.

People wearing wrist watches with tritium containing luminous dials will
certainly show highly elevated levels. We have done systematic tests with
plastic case watches and the volunteer wearing such a watch (it was me)
showed after about three weeks an equilibrium concentration of 3 000 Bq/l
urine. But also titanium and steel encased watches with tritium containing
luminous dials will give elevated values of tritium in urine. For more
detailed information please contact me directly by e-mail.

Franz