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AW: Radiometric forensics







Franz Schoenhofer

PhD, MR iR

Habicherg. 31/7

A-1160 Vienna

AUSTRIA

phone -43-0699-1168-1319



Emiel,



I do not think, that in the year 2004 a proof is possible, that somebody

lived in the Chernobyl area - whether before or now. 



The reasons are the following:



Contamination was very different in different parts of the Ukraine. The

only really extremely contaminated area is in the 30 km exclusion zone -

and even there irregularily distributed. 



Cs-137 is accumulated in muscle tissue and not in bone, as well not in

fatty tissue. I do not know the actual concentration of Cs-137 in

nowadays food from the vicinity of Chernobyl, but am rather sure, that

it is very low already. If this person had lived there some time ago

only, when there were elevated Cs-137 concentrations in food, then he

will have excreted all Cs-137 - biological half-life is approx. 70 to

120 days. This means that Cs-137 would not be found in muscle tissue. 



Actinides were almost exclusively emitted as part of hot particles -

mostly nuclear fuel, but also graphite particles - which contained the

actinides and are more or less insoluble. It turned out, that they

weather now, but I can give you no information by heart. Most of the

actinides (as well as Sr-90) were deposited in the vicinity of the

reactor and in the 30 km exclusion zone nobody is allowed to live, so in

principle nobody could take them up since a few days after the accident.

I do not know, whether they accumulate in bone. 



Sr-90 might be worth to consider, but I am very pessimistic. Most of

Sr-90 was deposited also in the 30 km exclusion zone. There exist maps

of both Cs-137 and Sr-90 contamination distribution, but I do not have

them at hand, because I retired last December and still have not found

time to organize the tons of reports, books and papers I took home. The

distributions look very similar - not surprising. I can give you a

comparison: We found Sr-90  in Austria for instance in milk, cheese,

precipitation and soil. The values for instance in soil or milk were

about twice the values before the accident, since Sr-90 still is present

from the atmospheric nuclear bomb tests. After one year the values were

at the same levels as in 1985. We conducted a big research programme to

use Sr-90 in red deer antlers as a bioindicator as a tool to

retrospectively investigate Sr-90 contamination of the environment in

Austria back to 1955. The values we found - and you know, that antlers

consist of bone matter! - were as well a hardly recognizable  small rise

just for 1986, which came back the following year to the levels of 1985.

Of course the Sr-90 contamination will have been much higher in the

vicinity of Chernobyl, but I guess that the overall pattern of behaviour

in the ecosystems must have been similar. 



I do not know of any recent investigation of Sr-90 in human bones, but

you can be sure that no Cs-137 would be present. 



The only strategy to make sure might be to do an analysis for Sr-90 in

bone and if there would be really high values found, you could go deeper

into the radioecological circumstances which sure would not be easy.





Sorry for the negative answer, but it might save you a lot of time and

effort!



Best regards,



Franz



-----------------------------------------------------------------------







-----Ursprüngliche Nachricht-----

Von: owner-radsafe@list.vanderbilt.edu

[mailto:owner-radsafe@list.vanderbilt.edu] Im Auftrag von E. van der

Graaf

Gesendet: Dienstag, 31. August 2004 16:43

An: radsafe@list.vanderbilt.edu

Betreff: Radiometric forensics



A torso of the body (estimated 20-40 years old) of an unidentified male

has been found in the Netherlands last year. Stable isotopes (H, C, N,

Sr and Pb)seem to indicate that this man has lived in the Ukraine,

Russia. Considering

his age he probably lived in that area during Chernobyl. In that case he

most likely has radionuclides originating from the accident in his

bones? 



Does anyone have a suggestion if it is possible to prove by measurement

of

any (which?) of these radionuclides if the man really lived in the

Chernobyl area?



Also what would be the best reference for normal activity concentrations

in

human bones of likely 'Chernobyl' radionuclides (137Cs, 90Sr,

actinides?).





Emiel R. van der Graaf

Nuclear Geophysics Division

Kernfysisch Versneller Instituut

Zernikelaan 25

9747 AA Groningen

The Netherlands

tel:  +31-50-3633562

fax: +31-50-3634003









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