UK letter on " Australian radiation victims "

["Franta, Jaroslav" <frantaj@aecl.ca>]

....from the current issue of New Scientist :

http://www.newscientist.com/letters/letters_224810.html
Australian radiation victims
Your Newswire item on the Australian soldiers who died of cancer following
exposure to radiation in Hiroshima was misleading (10 June, p 19).
The Federal Court of Australia did not rule "that two soldiers died of
cancer because they were exposed to low levels of radiation while occupying
Hiroshima in 1945". The court upheld an earlier decision of the
Administrative Appeals Tribunal (AAT) that a possible link existed between
the soldiers' cancers and their exposures to radiation. The court dismissed
an appeal by the Repatriation Commission against the AAT's decision that the
soldiers' widows were entitled to war widow's pensions.
I did not actually tell the federal court anything and I did not participate
in its proceedings. In 1997, I had provided evidence to the AAT. Some of
this evidence was quoted in the court's decision in 2000. Your item
misrepresented my evidence by quoting my words "Even extremely low doses
have an associated risk" out of context. The court's decision quoted me
correctly as follows:
"The estimation of risks at low levels of radiation involves an assumption
that all doses of radiation, even extremely low doses, have an associated
risk which increases with increase in dose."
I believe that the above assumption leads to the substantial overestimation
of risks from low doses. Nevertheless, on the basis of this assumption, I
provided the AAT with an estimate that the presumed exposures to about 1
millisievert of radiation at Hiroshima would have caused a fatal cancer risk
of about one chance in 20 000 for each of the soldiers. This estimate was
quoted in the court's decision.
I also told the AAT that another possible effect of a low dose of radiation
is to stimulate the immune system and thus to provide protection against
cancers, including cancers not caused by radiation. Like the possible
carcinogenic effect, this may vary from person to person. The net effect of
radiation on the incidence of cancer in an exposed group depends on the
balance between the damaging effects on DNA molecules and the protective
effects of stimulating the cellular DNA repair functions.
However, for an individual who is not suffering from cancer, it is clear
that far and away the most likely health effect of exposure to low radiation
doses (up to at least 200 millisieverts) is no effect at all.
Shortly after giving evidence to the AAT, I was exposed to about 20
millisieverts in a period of less than 6 months. I assure you that I am not
losing any sleep over this.
D. J. Higson 
Paddington 
New South Wales 
higsond@bigpond.com 

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