[ RadSafe ] LNT Dogma? - Future of Radiation Safety Regulations

Doss, Mohan Mohan.Doss at fccc.edu
Mon Aug 24 13:05:34 CDT 2015

Dear Mike,
     I also respectfully disagree with what you stated. The example you quoted in navy worked, and so it was being used, even though the underlying model was wrong.  If the method did not work, they would not have continued using it. They would have tried something else.
    With the LNT model, its use has not led to reduction of cancers (or prevention of cancers that would have occurred in the absence of its use) but has led to increase in cancers (by preventing the activation of radiation hormesis). For example, as reported in (Hwang, 2006), Taiwan apartment building residents, who got exposed to average of 5 cSv dose from contaminated building materials, had ~20% less all cancers compared to an age-matched control population. If ALARA had been practiced (if they knew of the contamination at the time they moved in, the residents would have been evacuated based on the LNT model and ALARA, just like it happened in Fukushima), they would not have this 20% reduction in cancers.   In Fukushima, they evacuated based on ALARA and the LNT model based fears, and this  caused immediate deaths, and they avoided low doses of radiation, and so did not received the benefit of reduced cancers.  So the LNT model and ALARA  have proven to be deadly to the public, and so they must not be used. We should learn from our mistakes.  I fail to see any arguments for the continuing use of the LNT model and ALARA. I am somewhat perplexed why those who are paid to protect public health would continue to support the use of the LNT model and ALARA. 
   There is plenty of data that directly contradicts the LNT model, since low-dose radiation has been observed to reduce naturally occurring cancers (not just those caused by subsequent insults). You don't need gut feeling when there is data.  As seen in slide 4 of the presentation link below, the observed reduction in cancers from low-dose radiation exposures has ranged from 15 to 40 per cent.  This is indeed impressive enough to overcome the LNT model dogma. 
   Your concerns about different thresholds for different people, etc. relate to high doses, not low doses of radiation. In view of the large reduction in cancers from using low-dose radiation (on the average), even those in the outliers of radiation response curve would most likely benefit from low-dose radiation.  
  With best regards,

-----Original Message-----
From: radsafe-bounces at agni.phys.iit.edu [mailto:radsafe-bounces at agni.phys.iit.edu] On Behalf Of Brennan, Mike (DOH)
Sent: Thursday, August 20, 2015 5:36 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] LNT Dogma? - Future of Radiation Safety Regulations

Hi, Dr. Doss.

With all due respect, I must disagree.  I can understand believing LNT is probably wrong, but still using it.  One of the epiphanies I've had (I've had four) is "All models are wrong and some are useful".  Models are not reality, but simplifications of reality.  It is possible to understand that a model fails in some aspects but still use it productively.  

One of the clearest examples I've encounter was when I was a submariner, involving the Ekelund technique for finding the range to a contact using passive sonar http://www.navy.mil/navydata/cno/n87/usw/issue_15/ekelund.html.  It is an interesting bit of dynamic geometry, that can only be done by assuming as true three things that are known (not suspected, but known) to be false.  If you make that assumption, you can get a range good enough to shoot a torpedo with.  If you don't make that assumption, you can't solve the problem.  

As for LNT, my "gut feeling" is that there are a lot of variables, many of which are unknown and some may well be unknowable with current technology.  I believe that for many different types of radiation exposure (and I am not a fan of trying to lump them all together) there are likely thresholds below which no increase in cancer would be observed, but I suspect those thresholds differ from person to person, and possible for an individual over the course of their life, based on many factors.  

As for hormesis, again my gut feeling is that it is not a direct phenomenon, in that "X exposure causes Y reduction in cancer", but rather "X exposure can cause Y change in something, which can cause Z change in response to cancer and/or cancer causing stimuli".  I think that both our understanding of cancer (which more and more I feel is not a useful term, as it lumps too many different things together) and hormesis.  I, personally, would like to see hormesis make a serious run on LNT, but I think it will have to be pretty impressive to overcome the dogma.  

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of Doss, Mohan
Sent: Thursday, August 20, 2015 12:35 PM
To: The International Radiation Protection (Health Physics) Mailing List
Subject: Re: [ RadSafe ] LNT Dogma? - Future of Radiation Safety Regulations

Dear All, 
    It is ironic that the individual quoted below believes the LNT model is almost certainly wrong, and still is a strong proponent of the model. If one believes some concept is wrong or is almost certainly wrong, one should be a strong opponent, not a strong proponent of that concept. If the statement by this individual is the best summation of the LNT model, it is really a pathetic situation (for the LNT model). 
    Keeping in mind the accepted criterion that book-keeping should be made easier, in contrast to the LNT model (which is almost certainly wrong, as stated by the strong proponent - I accept his judgement), the radiation hormesis model (which is almost certainly correct, as stated by me, a strong proponent, because there is plenty of data supporting it - see presentation at link below), if used for regulations, would simplify book-keeping tremendously, as no book-keeping need be required for low-doses, since cancer risks would be lowered by low-dose radiation. The current proponents of the LNT model (who desire simpler book-keeping) should welcome this!  The regulations should of course require book-keeping for potential high dose situations, but these would be few and far between.  There is a wide gap that separates low doses that are beneficial from high doses that are harmful, and so it would be easy to separate the two situations, and require book-keeping only for the latter. I discussed this concept for radiation protection regulations (for the future, if radiation hormesis concept is accepted) at the recent HPS Annual Meeting in the Low-dose symposium. If anyone is interested in viewing the presentation, it is available in ResearchGate at: https://goo.gl/A7EcfB . I welcome comments and criticisms, either in this forum or via private email. Thanks.
   With best regards,

Mohan Doss, Ph.D., MCCPM
Medical Physicist,
Associate Professor, Diagnostic Imaging, Fox Chase Cancer Center,
333 Cottman Avenue,
Philadelphia, PA 19111-2497.
Phone: 215 214-1707
Website: http://www.fccc.edu/research/pid/doss/
Blogs: http://mohan-doss-home-page.blogspot.com/

-----Original Message-----
From: radsafe-bounces at health.phys.iit.edu [mailto:radsafe-bounces at health.phys.iit.edu] On Behalf Of KARAM, PHILIP
Sent: Tuesday, August 18, 2015 3:36 PM
To: The International Radiation Protection (Health Physics) Mailing List <radsafe at health.phys.iit.edu>
Subject: Re: [ RadSafe ] LNT Dogma?

The best summation of LNT that I've heard was from a strong LNT proponent (sorry - can't remember his name at the moment). In a discussion after some presentations he said "LNT is almost certainly wrong, but it makes the book-keeping easy."

According to the final arbiter of all knowledge (Wikipedia) "Dogma is a principle or set of principles laid down by an authority as incontrovertibly true. It serves as part of the primary basis of an ideology or belief system, and it cannot be changed or discarded without affecting the very system's paradigm, or the ideology itself."

LNT is not scientific dogma, but it has effectively become dogma for the ALARA philosophy, and near-dogma for regulatory, national, and international advisory bodies. And I would say that it is certainly dogma for all of the anti-nuclear and anti-radiation groups.


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