[ RadSafe ] Low-level radiation benefits

[parthasarathy k s]

'Dear Dr.Muckerheide,
 
Thank you very much for the comments on my article "Is low level radiation beneficial?" in todays Hindu Newspaper. The  quotation from ICRP  refers to para 47 from ICRP publication No 60. Frankly, I could not locate any error in the quotation.
 
There were some omissions. I had included the full title of Dr Cameron's paper.I referred to Marshall Brucer's comments which also got omitted during editing. 
 
I made a mistake in typing my e-mail ID in the article. The correct ID is ksparth at yahoo.co.uk
Because of the lapse I have not received any feedback om my article so far!
 
Regards,
 
K.S.Parthasarathy

"Muckerheide, James" <jimm at WPI.EDU> wrote:
Friends,

This article is by our friend Dr. Parthasarathy in India, quoting our friends
Don Luckey and John Cameron. Note the error in the quote from ICRP: "In
particular radiation may be able to stimulate the repair of prior radiation
damage, thus decreasing its consequences or may be able to improve
immunological surveillance, thus strengthening the body's natural
mechanisms." This should delete "radiation," to correctly reflect that
radiation is shown to "stimulate repair of (all) prior damage," which is
overwhelmingly caused by the much greater sources of normal metabolic damage
to DNA and cells, especially from food and exercise. This successfully
reduces pre-cancerous lesions and cells, resulting in lower cancer rates in
LDR-exposed organisms. Of course, this is not expressed in most cellular
studies, which do not have the essential cellular and DNA repair mechanisms,
including stimulation of cell removal through necrosis and apoptosis, that
exist in immunologically-whole organisms and animals.

Regards, Jim Muckerheide



http://www.hindu.com/seta/2005/09/29/stories/2005092900601600.htm 

Is low-level radiation beneficial? 

________________________________

* Effects observed included increase in life span of invertebrates 

* Mainstream scientists have questioned the results of the studies 

* Data insufficient to take them into account in radiological protection 

________________________________

IN THE early 80's if anyone claimed that low-level exposure to ionising
radiation has a beneficial effect, the response would have been a bland smile
followed by a smirk! But currently many scientists are pursuing the concept
with evangelic zeal. Hormesis is defined as the stimulating effect of small
doses of substances, which in larger doses are inhibitory. 

In 1981, T.D. Luckey revived `hormesis' with reference to ionising radiation
backing it up with 1250 articles. The effects observed included the growth of
algae under X-irradiation, growth of peas, increase in life span of
invertebrates and insects and seedling stimulation by X-rays. Luckey wrote a
very interesting book titled Radiation Hormesis. 

John Cameron, emeritus professor, University of Wisconsin published in the
Forum on Physics and Society (2001). 

He argued that the U.S. Gulf States have a high cancer death rate compared to
the mountain states although background radiation is much lower in the Gulf
States. He suggested that they are suffering from "radiation deficiency"!
Mainstream scientists have questioned the results of such ecological studies.


Cameron referred to an unpublished study, which showed that nuclear shipyard
workers who were exposed to more than 5mSv of dose had a death rate from all
causes, which was 24 per cent lower than the control group. Writing in the
Environmental Pollution Journal (2005), Edward J. Calabrese, Professor at the
University of Massachusetts at Amherst provided substantial evidence that
hormesis is real, reproducible and in properly designed studies very common,
in fact more common than any other dose-response model. 

Genetic effects 

For instance, H. Muller who demonstrated genetic effects by irradiating fruit
flies in 1927, predicted a genetic catastrophe from atomic bomb explosion.
This lead to feverish publicity. But there was no publicity for the disproof
35 years later. The story of double-headed babies in Hiroshima and Nagasaki
was fiction; but it made good copy. 

Repair mechanisms 

The interaction of radiation with tissue is not just a purely physical
mechanism. We cannot ignore the profound biological defence mechanisms. B.L
Cohen (Risk Analysis, 1995) reviewed the evidence that biological defence
mechanisms are stimulated by low-level radiations. 

In 1991, the International Commission on Radiological Protection stated:
"There is some experimental evidence that radiation can act to stimulate a
variety of cellular functions including proliferation and repair. Such
stimulation is not necessarily beneficial. In some circumstances, radiation
appears also to enhance immunological responses and to modify balance of
hormones. 

In particular radiation may be able to stimulate the repair of prior
radiation damage, thus decreasing its consequences or may be able to improve
immunological surveillance, thus strengthening the body's natural
mechanisms." 

ICRP stated that the data on hormesis are not sufficient to take them into
account in radiological protection. The Committee on the Biological Effects
of Ionizing Radiation has stated that the assumption that any stimulatory
hormetic effects from low doses of ionizing radiation will have a significant
health benefit to humans that exceeds potential detrimental effects from
radiation exposure is unwarranted at this time". 

K.S. Parthasarathy 
Department of Atomic Energy, Mumbai 
ksparth at yahoo.com 







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