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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References:
1. Calabrese EJ. The road to linearity: why linearity at low doses became the basis for carcinogen risk assessment. Arch Toxicol 2009;83:203-25. doi:10.1007/s00204-009-0412-4. http://www.ncbi.nlm.nih.gov/pubmed/19247635 2. Calabrese EJ. How the US National Academy of Sciences misled the world community on cancer risk assessment: new findings challenge historical foundations of the linear dose response. Arch Toxicol 2013. doi:10.1007/s00204-013-1105-6. http://www.ncbi.nlm.nih.gov/pubmed/23912675 3. Cuttler JM. Leukemia incidence of 96,000 Hiroshima atomic bomb survivors is compelling evidence that the LNT model is wrong. Archives of Toxicology 2014;Online First. doi:10.1007/s00204-014-1207-9. http://rd.springer.com/article/10.1007/s00204-014-12079/fulltext.html 4. Doss M. Adoption of Linear No-Threshold Model Violated Basic Scientific Principles and Was Harmful. Archives of Toxicology 2014; (Pre Press). doi:10.1007/s00204-014-1208-8. http://rd.springer.com/article/10.1007/s00204-014-1208-8/fulltext.html 5. Luckey TD. Hormesis with ionizing radiation. Boca Raton, Fla.: CRC Press; 1980 6. Doss M. Correcting Systemic Deficiencies in Our Scientific Infrastructure. Dose Response 2014; In Press. doi:10.2203/dose-response.13-046.Doss. http://doseresponse.metapress.com/link.asp?id=11h3l8t067886g08 7. Cohen BL. Cancer risk from low-level radiation. AJR Am J Roentgenol 2002;179:1137-43. doi:10.2214/ajr.179.5.1791137. http://www.ncbi.nlm.nih.gov/pubmed/12388487 8. Feinendegen LE. Evidence for beneficial low level radiation effects and radiation hormesis. Br J Radiol 2005;78:3-7. http://www.ncbi.nlm.nih.gov/pubmed/15673519 9. Tubiana M. Dose-effect relationship and estimation of the carcinogenic effects of low doses of ionizing radiation: the joint report of the Academie des Sciences (Paris) and of the Academie Nationale de Medecine. Int J Radiat Oncol Biol Phys 2005;63:317-9. http://www.ncbi.nlm.nih.gov/pubmed/16168825 10. NRC. Health risks from exposure to low levels of ionizing radiation : BEIR VII Phase 2, National Research Council (U.S.). Committee to Assess Health Risks from Exposure to Low Level of Ionizing Radiation. Washington, D.C.: National Academies Press; 2006. http://www.nap.edu/catalog.php?record_id=11340 11. Brenner DJ, Hall EJ. Computed tomography--an increasing source of radiation exposure. N Engl J Med 2007;357:2277-84. http://www.ncbi.nlm.nih.gov/pubmed/18046031 12. Ozasa K, Shimizu Y, Suyama A, Kasagi F, Soda M, Grant EJ, et al. Studies of the mortality of atomic bomb survivors, Report 14, 1950-2003: an overview of cancer and noncancer diseases. Radiat Res 2012;177:229-43. http://www.ncbi.nlm.nih.gov/pubmed/22171960 13. Doss M. Linear No-Threshold Model vs. Radiation Hormesis. Dose Response 2013;11:480-97. doi:10.2203/dose-response.13-005.Doss. http://www.ncbi.nlm.nih.gov/pubmed/24298226 14. Sasaki MS, Tachibana A, Takeda S. Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors. J Radiat Res 2014; In Press. doi:10.1093/jrr/rrt133. http://www.ncbi.nlm.nih.gov/pubmed/24366315 15. Cardis E, Vrijheid M, Blettner M, Gilbert E, Hakama M, Hill C, et al. Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries. BMJ 2005;331:77. doi:10.1136/bmj.38499.599861.E0. http://www.ncbi.nlm.nih.gov/pubmed/15987704 16. Cardis E, Vrijheid M, Blettner M, Gilbert E, Hakama M, Hill C, et al. The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry: estimates of
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radiation-related cancer risks. Radiat Res 2007;167:396-416. http://www.ncbi.nlm.nih.gov/pubmed/17388693 17. CNSC. INFO-0811. Verifying Canadian Nuclear Energy Worker Radiation Risk: A Reanalysis of Cancer Mortality in Canadian Nuclear Energy Workers (1957-1994) Summary Report, Canadian Nuclear Safety Commission. 2011;Accessed Sep 1, 2013. http://goo.gl/m4NW3p Published June 2011. 18. Zablotska LB, Lane RS, Thompson PA. A reanalysis of cancer mortality in Canadian nuclear workers (1956-1994) based on revised exposure and cohort data. Br J Cancer 2014;110:214-23. doi:10.1038/bjc.2013.592. http://www.ncbi.nlm.nih.gov/pubmed/24231946 19. Fornalski K, Dobrzynski L. Ionising radiation and the health of nuclear industry workers. International Journal of Low Radiation 2009;6:57-78. doi:10.1504/IJLR.2009.026240. http://www.inderscience.com/info/inarticle.php?artid=26240 20. Fornalski KW, Dobrzynski L. The healthy worker effect and nuclear industry workers. Dose Response 2010;8:125-47. doi:10.2203/dose-response.09-019.Fornalski. http://www.ncbi.nlm.nih.gov/pubmed/20585442 21. Tubiana M, Diallo I, Chavaudra J, Lefkopoulos D, Bourhis J, Girinsky T, et al. A new method of assessing the dose-carcinogenic effect relationship in patients exposed to ionizing radiation. A concise presentation of preliminary data. Health Phys 2011;100:296-9. http://www.ncbi.nlm.nih.gov/pubmed/21595074 22. Sakamoto K. Radiobiological basis for cancer therapy by total or half-body irradiation. Nonlinearity Biol Toxicol Med 2004;2:293-316. doi:10.1080/15401420490900254. http://www.ncbi.nlm.nih.gov/pubmed/19330149 23. Feinendegen LE, Pollycove M, Neumann RD. Hormesis by Low Dose Radiation Effects: LowDose Cancer Risk Modeling Must Recognize Up-Regulation of Protection. In: Baum RP, editor. Therapeutic Nuclear Medicine: Springer; 2013. 24. Thompson RE. Epidemiological Evidence for Possible Radiation Hormesis from Radon Exposure: A Case-Control Study Conducted in Worcester, MA. Dose Response 2011;9:59-75. doi:10.2203/dose-response.10-026.Thompson. http://www.ncbi.nlm.nih.gov/pubmed/21431078 25. Cohen B. The Cancer Risk from Low-Level Radiation. In: Tack D, Gevenois P, editors. Radiation Dose from Adult and Pediatric Multidetector Computed Tomography. Berlin: SpringerVerlag; 2007. p. 33-49. 26. Farooque A, Mathur R, Verma A, Kaul V, Bhatt AN, Adhikari JS, et al. Low-dose radiation therapy of cancer: role of immune enhancement. Expert Rev Anticancer Ther 2011;11:791-802. doi:10.1586/era.10.217. http://www.ncbi.nlm.nih.gov/pubmed/21554054 27. Ichiseki H. Features of disaster-related deaths after the Great East Japan Earthquake. Lancet 2013;381:204. doi:10.1016/S0140-6736(13)60091-4. http://www.ncbi.nlm.nih.gov/pubmed/23332962 28. McLernon S. US Sailors Seek $1B From Tepco For Radiation Exposure. 2014. http://www.law360.com/articles/508457/us-sailors-seek-1b-from-tepco-for-radiation-exposure 29. Wei LC, Ding YX, Liu YH, Duan L, Bai Y, Shi M, et al. Low-dose radiation stimulates Wnt/beta-catenin signaling, neural stem cell proliferation and neurogenesis of the mouse hippocampus in vitro and in vivo. Curr Alzheimer Res 2012;9:278-89. doi:CAR-EPUB-20120123-014 [pii]. http://www.ncbi.nlm.nih.gov/pubmed/22272614 30. El-Ghazaly MA, Sadik NA, Rashed ER, Abd El-Fattah AA. Neuroprotective effect of EGb761(R) and low-dose whole-body gamma-irradiationin a rat model of Parkinson's disease. Toxicol Ind Health 2014; In Press. doi:10.1177/0748233713487251. http://www.ncbi.nlm.nih.gov/pubmed/23696346
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31. Hendee WR, O'Connor MK. Radiation risks of medical imaging: separating fact from fantasy. Radiology 2012;264:312-21. doi:10.1148/radiol.12112678. http://www.ncbi.nlm.nih.gov/pubmed/22821690
Note: This Open Letter was e-mailed to the following advisory bodies on Feb 28, 2014: ICRP, NCRP, UNSCEAR, IAEA, WHO, NAS Copyright Š 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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