RE: Compensation of survivors -- bomb test exercises -- uptake of radionuclides

[andrew_mcewan@nrl.moh.govt.nz]

Dukelow, James S Jr wrote:



If I am remembering correctly, soldiers who participated in bomb test

exercises

were never monitored for internal uptake of radionuclides.  How can you know

that exposures were small?

__________________________________________________________

Both Jaroslav and Franz have commented on this.  Some further remarks on Franz's response to Jaroslav.  In planned troop involvements in fallout zones

external radiation doses were either individually measured (as in the Buffalo test in Australia) or estimated with a representative number of troops

individually monitored.  The primary route of exposure was external radiation, particularly where entry to zones was after deposition of local fallout

and respiratory protection was used.  The respiratory protection was to minimise inhalation of resuspended material, and assessments carried out at

the time (at least in the case of the Buffalo indoctrinees) demonstrated that there was no significant intake via inhalation.  For people exposed

directly in a fallout zone without any precautions the major route of intake is generally ingestion, rather than inhalation.  In the case of troops

appropriate precautions were taken against ingestion and skin contamination as well as inhalation.  In the case of the Rongelap Islanders, while

inhalation of iodines during the passage of the cloud was a contributor to internal dose, the dominant route of thyroid exposure was ingestion.

External radiation was the dominant contributor to whole body dose, and material deposited directly on skin gave high beta doses to skin.



In the case of troops stationed on Christmas Island during the UK atmospheric tests, most of the tests and all the Mt yield tests were conducted away

from the island and at altitudes where the fireball remained well above sea level.  This led to there being very little local fallout.  The point

about the 1981 measurements of Cs-137 on Christmas Island is that the levels were so low (consistent with global fallout for an equatorial region)

that it was evident there had been no local fallout enhancement of deposition.  Since Cs-137 and shortlived fallout nuclides are deposited in roughly

fixed ratios this demonstrated that there could not have been any significant deposition of fallout on the island at the time, or during the US series

of tests conducted from Christmas Is in 1962.



Andrew McEwan



_________________________

Andrew C McEwan PhD

National Radiation Laboratory

PO Box 25-099

Christchurch, New Zealand



Ph 64 3 366 5059

Fax 64 3 366 1156

Andrew_McEwan@nrl.moh.govt.nz