AW: [ RadSafe ] lethal amount of Po-210

[Franz Schönhofer]

Dear Laszlo,

By chance I have been in London during the days when it became known, that a
person had been poisoned by Po-210. TV showed clearly a chemist, who was
using a beaker, which was stirred - with other words, this was without any
doubt the well known plating of Polonium to a disc of whatever suitable
metal (Ag, Cu,....). Knowing the expertise of our collegues from England
very well I cannot assume that they intended to measure traces of Po-210 by
gamma-spectrometry. 

You did not specify, which method you used for your survey on childrens
urine in the 80's. Not really being an expert in dose calculation from
intake I still have a feeling, that the concentrations of Po-210 in urine
are by orders of magnitude to high. Values of up to 3 Bq/l urine are
scaring. Compare that to the recommendation of the European Union on Pb-210
and Po-210 concentrations in drinking water!

Please give me further information - I hope I am wrong.

Best regards,

Franz  

Franz Schoenhofer
PhD, MR iR
Habicherg. 31/7
A-1160 Vienna
AUSTRIA
phone -43-0699-1168-1319


> -----Ursprüngliche Nachricht-----
> Von: radsafe-bounces at radlab.nl [mailto:radsafe-bounces at radlab.nl] Im
> Auftrag von Toro Laszlo
> Gesendet: Donnerstag, 14. Dezember 2006 14:19
> An: radsafe at radlab.nl
> Betreff: [ RadSafe ] lethal amount of Po-210
> 
> Dear Collegues,
> 
> In the absence of quantitative information related to
> the amount of Po-210, I made some calculations started
> from ther information:
> "How do we know it is Polonium-210?
> Analysis of samples taken from the deceased person
> identified Polonium-210 through its characteristic but
> weak emission of gamma rays. This and further tests
> are consistent with the deceased person having had a
> large intake of Polonium-210. "
> (http://www.nhsdirect.nhs.uk/articles/article.aspx?articleId=2086)
> Assuming:
> - they used a 30-40% relative efficiency well type
> HPGe based gamma spectrometer
> - a minimal value of a peak area (at 803keV) to be
> considered by a skilled gamma spectrometrist "as peak"
> about 2-3 E-3 ips (about 400-500 impulses in the whole
> peak in 2E5 seconds)
> -the measured sample is an urine sample taken after
> 7days from the ingestion (some source give 8 of
> November the admitance in the hospital)
> Results:
> - the minimal activity measured in the sample is about
> 4000Bq
> -the total ingested activity at 1 of November is
> between 4-21MBq (0.1-0.6mCi; some tens-hundred ngram)
> -the dose (according ICRP 67 dose factors) is 5-25 Sv
> If somebody is interested in the whole calculations
> and assumtions I can send it privatelly (it was a good
> exercice for dose reconstruction).
> Regarding the "mass tests" for Po-210, I found some
> old results in our files:
> Po-210 in urine
> 1983(samples from 70 subjects, children between
> 10-15y, from three rural communities) 304 mBq/l
> (extreme values 222-518 mBq/l)
> 1983(samples from 77 subjects, children between
> 10-15y, from other three rural communities but
> fundamentally different habits) 1.88 Bq/l (extreme
> values 148-2930 mBq/l)
> 1988 (collective sample from 20 subjects, children
> between 10-15y, from a school from Timisoara) 82mBq/l
> with no significant difference femal/male.
> It seems everybody of us should be found "positive"
> against a Po-210 test.
>  Sorry for this long message.
> 
> Laszlo Toro
> 
> ======================================================================
> Laszlo Toro PhD
> senior scientist
> 
> Institute of Public Health Timisoara
> Radiation Hygiene Dept.
> 
> RO 300226 Timisoara
> Bd. V. Babes 16-18
> Romania
> ph. +40 256 492101 ext 34
> fax +40 256 492101
> e-mail toro at ispt.ro
>        torolaszlo at yahoo.com
> ======================================================================
> 
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