Re: Radiation hormesis

["Alex Zapantis" <alex.zapantis@ea.gov.au>]

G'day all

LNT applies to stochastic effects. Sunburn and falling 30m to ones death are deterministic effects. Melanoma is considered (I think) to be a stochastic effect. In Australia, where almost everyone gets some sort of skin cancer in their lifetime, the message delivered in anti skin cancer campaigns is based on a philosophy which is analogous to the ALARA principle - minimise exposure to sun, use sunscreen, shirt, hat, sunglasses when outside, avoid outdoor activity in the middle of the day if possible.....

So IR is not treated all that differently UV from the sun here, except that there are no regulatory limits for exposure. If we applied the "system of radiological protection" to UV exposure from the sun, the social and economic considerations required by the ALARA principle would probably necessitate essentially the status quo. 

Cheers

Alex


>>> <tmohaupt@wright.edu> 05/07/99 04:06am >>>
Radsafers,

Glen presents an interesting point of view.  Since ionizing radiation 
is simply a form of energy, it can be readily compared with other 
forms of energy and their effects.  Keep in mind that there is no 
type of energy that is safe in high levels.  Radiation is the only 
one to which a LNT is applied.  The LNT is a political 
position and, most likely, not an accurate description of reality.  
Personally, I'd like to see radiation regulated to prevent real 
damage, much the way we do with other forms of energy, rather than 
treat it like the witchcraft trails of the late 17th century in New 
England.

An example:  Sunlight is known to cause cancer, cataracts, and a host 
of other detrimental effects.  If, out of precaution for the health and 
well being of the general public, a Solar Regulatory 
Commission decided to apply a linear no-threshold model to solar 
radiation risk, we would probaby have to close beaches and other 
outdoor activities to keep exposure limits within acceptable limits.  Even on a 
cloudy day you would be exposed, and that may be unacceptable, unless 
you have a need to be outside that overrode the risk.  If a lifeguard 
gets melanoma 20 years later, can he/she sue his employer to a 
hazardous working environment?  But wait, sunlight is essential for 
life!  Being exposed 60 times in a day for 1 minute each time is 
beneficial (i.e., promotes Vitamin D), where one exposure of 60 
minutes can result in sunburn, which is a significant risk factor for 
skin cancer.  How does one assure that recurrent exposures to trace 
levels of sunlight do not cause sun cancer?
What about potential energy (ie altitude)?  If a person falls from 
100 feet, there's a strong liklihood the person would die.  The LNT 
would say that if you hop to a height of 6 inches, one out of  
200 hops you would die.  That's not true.  It's called exercise and 
it is promoted as a salubrious effect.  Once again the LNT doesn't fit 
and shouldn't be applied.
Name the energy, electricity, UV radiation, heat, impact, wind, etc.,   
Each has levels where truly harmful effects can be observed.  And 
each has lower levels which are either beneficial or inconsequential. 
Ionizing radiation is no different.
How does this apply to the proposed rules for setting an allowance 
limit for releasing metals for recycling to the public domain?  The 
proposed release values will result in exposures that are fractions 
of background or inconsequential compared to the natural variability 
of background.  We cannot prove radiation is safe in low levels; however 
we do know that low levels are NOT UNSAFE, which is the same 
criteria we apply to all other forms of energy that we commonly 
experience.
Tom
 >In a message dated 5/4/99 6:04:57 PM EST, 7pe@ornl.gov writes:
 >
><< Why should the public take on any additional risk, no matter how trivial in
 > some people's opinion, to assist the nuclear/defense industry in getting
 > rid of their contaminated scrap?  The only measurable cost benefit is to
 > industry, none to the public (unless there IS a hormetic effect). >>
 >
 >Even IF there is a demonstrable hormetic effect, how does one assure that the
 >"beneficial" dose from contaminated scrap metal plus nuclear power plants
 >plus fossil-fuel power plants plus radwaste disposal facilities plus
 >household radon plus doctors' offices plus dentists' offices plus high-flying
 >airliners plus...plus...plus...is still "beneficial"?
 >
 >An exposure which ALONE might have a beneficial effect, might have a
 >detrimental effect when combined with all other exposures.  Unless the
 >proponents of radiation hormesis can assure that their proposed contribution
 >to the recipient's total exposure still has a cumulative hormetic effect,
 >hormesis should remain an interesting, but practically useless phenomena.
 >
 >Glenn
 >GACarlson@aol.com 
Tom Mohaupt, MS, CHP
Wright State University
Radiation Safety Officer

Voice:  (937) 775-2169
Fax:  (937) 775-3301
E-mail:  tom.mohaupt@wright.edu 
Address:  104 Health Sciences Bldg, Wright State University
          Dayton, OH 45435
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