An Open Letter to Professional Bodies§ Regarding Low Dose Radiation Cancer Risk
Dear Colleagues,
As described in the “Open Letter to Advisory Bodies Regarding Low Dose Radiation Cancer Risk”
(on Page 5), considerable evidence has accumulated on the invalidity of the linear no-threshold (LNT)
model that has been used for radiation safety purposes worldwide since the 1950s. The continuing
reluctance of the advisory bodies to discard the LNT model in spite of the overwhelming evidence against
it presents a dilemma to professional bodies. We believe that the leaders of the professional bodies will be
aware of the latest literature and the current spate of publications (see some examples in the enclosed
graphs) showing evidence against the LNT model and demonstrating the beneficial effects of low dose
radiation. Such publications have not been challenged or repudiated in any peer-reviewed publications.
If the professional bodies continue to use the LNT model to guide their policies and actions, they
are likely knowingly contributing to harming public health, since their policies and actions perpetuate
radiophobia, which can (i) result in harmful "precautionary" actions such as have occurred in Fukushima,
(ii) prevent study of low dose radiation for treating diseases for which presently there are no methods of
prevention or control and (iii) result in patients refusing needed diagnostic studies, studies being performed
with too low a dose and thus becoming non-diagnostic, and in physicians not ordering the needed
examinations. Radiophobia has also resulted in tremendous wastage of public funds.
The claim of “just following recommendations” would not be an acceptable justification for
harming public health when current literature overwhelmingly does not support the LNT model. Hence, it
is imperative that the professional bodies discard the use of the LNT model from an evaluation of the latest
evidence on their own. If the LNT model continues to be used, then it is requisite that a defensible reason
for discarding present evidence be proffered to the professional community. If reliance is placed on the
advisory body recommendations for continuing to use the LNT model, justification from the advisory
bodies is similarly required. Urgent action is advised.
We would be happy to discuss this matter with you or provide additional information for your
consideration. Thank you for your kind attention to this important issue.
Sincerely,
Wade Allison, Oxford University, UK
Allen Brodsky, Georgetown University, USA
Mervyn D. Cohen, Indiana University School of Medicine, USA
Jerry Cuttler, Cuttler & Associates, Canada
Ludwik Dobrzynski, National Center for Nuclear Research, Poland
Mohan Doss, Fox Chase Cancer Center, USA
Vincent J. Esposito, University of Pittsburgh, USA
Ludwig E. Feinendegen, Heinrich-Heine University, Germany
Krzysztof W. Fornalski, Polish Nuclear Society, Poland
Leo S. Gomez, Leo S. Gomez Consulting, USA
Patricia Lewis, Free Enterprise Radon Health Mine, USA
Jeffrey Mahn, Sandia National Laboratories (Retired), USA
SMJ Mortazavi, Shiraz University of Medical Sciences, Iran
Steven S. Payne, National Nuclear Security Administration (Retired), Col USAF (Retired), USA
Charles W. Pennington, Executive Consultant, USA
§
Any individual or group (private or government) that guides professionals or the public regarding health effects of low
dose radiation.
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Jeffrey S. Philbin, Sandia National Laboratories (Retired), USA
Chary Rangacharyulu, University of Saskatchewan, Canada
Charles L. Sanders, Korea Adv. Inst. of Science and Technology, S. Korea (Retired), USA
Michael G Stabin, Vanderbilt University, USA
Note: All signers of this letter are members or associate members of SARI (Scientists for Accurate
Radiation Information, http://radiationeffects.org/). The above letter represents the professional opinions of
the signers, and does not necessarily represent the views of their affiliated institutions.
Email: sari-email@googlegroups.com
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Evidence against the LNT model
Figure 1. Reduced second cancers/kg of tissue at 20 cGy in a study of 5,000 survivors of childhood
cancer who underwent radiation therapy and were followed an average of 29 y.
http://www.ncbi.nlm.nih.gov/pubmed/21595074
Figure 2. Improved survival in non-Hodgkin’s lymphoma patients when radiation therapy treatments
were interspersed with low dose radiation. http://www.ncbi.nlm.nih.gov/pubmed/19330149
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Figure 3. No increase in leukemia from low dose radiation in atomic bomb survivors. Threshold dose
is near 50 rem (50 cSv). http://www.ncbi.nlm.nih.gov/pubmed/24504164
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An Open Letter to Advisory Bodies1 Regarding Low Dose Radiation Cancer Risk
Dear Colleagues,
The linear no-threshold (LNT) model was adopted worldwide for radiation safety purposes in the
1950s following the recommendations of the various international and national advisory bodies [1]. The
decision to use a linear model was based on the observation of linear dependence of increased mutations in
drosophila melanogaster subjected to high dose radiation, and linear dependence of increased leukemias in
atomic bomb survivors exposed to high dose radiation. In spite of the considerable amount of evidence
available in the 1950s for the presence of a large threshold dose both for radiation-induced mutations [2]
and for leukemias [3], the concept of zero threshold dose was adopted by the advisory bodies, violating
basic scientific principles [4]. In addition, the consequent radiation safety policies recommended by the
advisory bodies to keep the radiation doses as low as reasonably achievable prevented the study of
radiation hormesis when it was proposed in 1980 [5]. Thus, these recommendations derailed the scientific
method, since one unverified hypothesis was used to prevent the study of a competing hypothesis, stalling
scientific progress in the field, and leaving the simple question whether the health effects of low dose
radiation are beneficial or harmful unresolved even after intense study for many decades [6].
Though there has been a considerable amount of published evidence against the LNT model for
radiation-induced cancers during the past several decades [5, 7-9], the LNT model continues to be widely
promulgated. The atomic bomb survivor data, for example, have been used to support the LNT model of
cancer risk in the influential BEIR VII report [10] and in many peer-reviewed publications, e.g. [11]. Even
in the latest update to the atomic bomb survivor data [12], the authors have claimed that zero dose is the
best estimate for a dose threshold for solid cancer mortality, apparently supporting the LNT model.
However, their dose-threshold analysis should be considered faulty since it restricted the possible
functional forms of the dose-response relationship a priori. An analysis that used a more general functional
form to fit the data has demonstrated that the presence of a dose threshold cannot be excluded [13]. In
addition, a recent analysis of the atomic bomb survivor data using artificial neural networks has revealed
the presence of a threshold dose that varied with organ, gender, etc. and the reduction of some cancers at
low doses [14].
Another study used to justify carcinogenic concerns from low doses of radiation in the BEIR VII
report and other publications [11] is the 15-country study of radiation workers [15, 16]. A re-analysis of
the cancer mortality data of the Canadian nuclear workers [17] has resulted in a negation of the original
conclusion of the entire 15-country radiation worker study regarding cancer risks from low doses of
radiation [18]. Also, a Bayesian analysis of the 15-country study data has shown there is too much scatter
in the data to make a definitive conclusion about the cancer risk from low doses of radiation, and that the
dismissal of reduction in overall cancers in the radiation workers is unjustified [19, 20].
Thus, the main arguments in the BEIR VII report (and other publications) supporting the LNT
model and increased cancer risks from low doses of radiation cannot be considered valid. Further, evidence
supporting alternate (non-LNT) models and the beneficial effects of low doses of radiation (i.e. radiation
hormesis) have been published since the time of the BEIR VII report [21-26], and the evidence presented
in these publications have not been challenged or repudiated in any peer-reviewed publication. The
advisory bodies have however ignored such publications without clearly stating why the evidence and
arguments presented in such publications are invalid, and they continue to promote the use of the LNT
model.
The continuing recommendations supporting the use of the LNT model by the advisory bodies has
had significant adverse societal implications, particularly with regard to radiation protection policies and
1
ICRP, NCRP, UNSCEAR, IAEA, WHO, NAS, …
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public perception regarding radiation risk. For example, use of the LNT model has led to substantial
casualties in real-life situations because of the ensuing fear of low doses of radiation among the general
public, and the actions taken by governments when handling radiological emergencies, e.g. in
Fukushima [27]. The use of the LNT model has also led to frivolous lawsuits when emergency responders
were exposed to low levels of radiation near Fukushima [28]. The unwarranted concerns regarding low
doses of radiation have discouraged study of the use of low dose radiation for the prevention and treatment
of cancer, even though animal and human studies have demonstrated its positive potential [22]. Such
concerns have also discouraged the study of low dose radiation for reducing neurodegenerative diseases for
which presently there are no methods of prevention or control, even though animal studies have shown
promise [29, 30]. Finally, unwarranted concerns about the low doses of radiation used in medical imaging
have led some patients to forego medically appropriate examinations, even when such exams are necessary
for accurate diagnosis or therapeutic planning [31]. Thus, though the LNT model was touted as a
conservative measure and a simplified, straightforward regulatory approach, its actual use has led to
tremendous harm, and it is imperative that alternative paradigms for radiation safety are considered and
adopted.
Considering the overwhelming amount of data that supports the validity of low dose radiation
adaptive protection [23] and the resultant invalidation of the LNT model, we urge you to recognize this
publicly with a declaration and recommend to governments that they discontinue the use of the LNT model
for radiation safety purposes, supplanting it with a threshold model.
We would be happy to discuss this matter with you or provide additional information for your
consideration. Thank you for your kind attention to this important issue.
Sincerely,
Wade Allison, Oxford University, UK
Allen Brodsky, Georgetown University, USA
Mervyn D. Cohen, Indiana University School of Medicine, USA
Jerry Cuttler, Cuttler & Associates, Canada
Ludwik Dobrzynski, National Center for Nuclear Research, Poland
Mohan Doss, Fox Chase Cancer Center, USA
Vincent J. Esposito, University of Pittsburgh, USA
Ludwig E. Feinendegen, Heinrich-Heine University, Germany
Krzysztof W. Fornalski, Polish Nuclear Society, Poland
Leo S. Gomez, Leo S. Gomez Consulting, USA
Ed Hiserodt, Controls & Power, Inc, USA
Marek K. Janiak, Military Institute of Hygiene and Epidemiology, Poland.
Patricia Lewis, Free Enterprise Radon Health Mine, USA
Jeffrey Mahn, Sandia National Laboratories (Retired), USA
Cynthia H. McCollough, Mayo Clinic, USA
Mark L. Miller, Sandia National Laboratories, USA
SMJ Mortazavi, Shiraz University of Medical Sciences, Iran
Steven S. Payne, National Nuclear Security Administration (Retired), Col USAF (Retired), USA
Charles W. Pennington, Executive Consultant, USA
Jeffrey S. Philbin, Sandia National Laboratories (Retired), USA
Chary Rangacharyulu, University of Saskatchewan, Canada
Charles L. Sanders, Korea Adv. Inst. of Science and Technology, S. Korea (Retired), USA
Bobby R. Scott, Lovelace Respiratory Research Institute, USA
Jeffry A. Siegel, Nuclear Physics Enterprises, USA
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Yehoshua Socol, Falcon Analytics, Israel
Michael G Stabin, Vanderbilt University, USA
James S. Welsh, President-elect, American College of Radiation Oncology, USA
Note: All signers of this letter are members or associate members of SARI (Scientists for Accurate
Radiation Information, http://radiationeffects.org/). The above letter represents the professional opinions of
the signers, and does not necessarily represent the views of their affiliated institutions.
Email: sari-email@googlegroups.com
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Note: This Open Letter was e-mailed to the following advisory bodies on Feb 28, 2014:
ICRP, NCRP, UNSCEAR, IAEA, WHO, NAS
Copyright © 2014 by Scientists for Accurate Radiation Information (SARI). You are encouraged to distribute
this Open Letter widely. You are given the right to make copies of this letter in full or in part, provided the
source of the copy is identified as Scientists for Accurate Radiation Information (SARI), with a link to the SARI
website: http://radiationeffects.org
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