End of LNT era (Mohn Doss) USofA

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The End of the LNT Era Presentation · June 2018

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The End of the LNT Era Mohan Doss, PhD, MCCPM Medical Physicist, Professor, Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, PA

E-mail: mohan.doss@fccc.edu Slightly revised version of the Presentation at the CE Session Radiopharmaceutical Dosimetry and Radiobiology – The Future is Now at the SNMMI Annual Meeting, June 25, 2018 Revised Version 1.1 dated July 4, 2018

Copyright Š 2018 by Mohan Doss Disclaimer: Opinions expressed in this presentation are my own professional opinion, and do not necessarily represent those of my employer.

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The End of the LNT Era - Preamble

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The LNT Era has not ended yet.

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But, there are some hopeful signs that we may be approaching the end of the LNT era.

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How to Resolve Controversial Issues in Science • For some issues, a substantial number of scientific publications would be found to support opposing points of view, making the issues controversial.

• However, we know that only one of those views can be correct, since they are opposing views, and the correct view would be determined in the future.

• Hence, during the period of controversy, a substantial number of publications would support the wrong point of view. How is this possible, when both sides claim that evidence supports their side, as is required by science?

• The reason is that publications supporting the wrong side have faulty data, analysis, and/or interpretation. Also, such publications would ignore opposing publications.

• When such faulty publications are identified, discredited, and eliminated from consideration, the single correct conclusion can be reached on the issue.

• I have done this in this presentation regarding the LNT model.

• However, advisory bodies, in their reports on low-dose radiation, have ignored publications supporting radiation hormesis but have used faulty publications to prop up the LNT model. I will point out examples of such actions by advisory bodies in this presentation. Such actions sustain the controversial issues without resolving them. 3

The Linear no-threshold (LNT) Model For Radiation-induced Cancer Excess Relative Risk (ERR) =

R  B B

R = Cancer Rate after Irradiation B = Background Cancer Rate

Problem with the model: The absence of threshold results in the fear of the smallest amount of radiation.

The LNT model was adopted by advisory bodies in the 1950s and has been endorsed by them repeatedly .

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Justification for the LNT model

• Even a small amount of radiation increases DNA damage and mutations • Increased mutations imply increased cancers, based on the somatic mutation model of cancer

Are these concepts valid?

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Do mutations increase with radiation dose at low doses? •Even in the absence of radiation, endogenous DNA damage does occur, (Vilenchuk & Knudson, 2003). •Though low-dose radiation causes some DNA damage, it also enhances defenses (antioxidants, DNA repair enzymes, etc.).

With the enhanced defenses, there would be less endogenous damage than would have occurred in the subsequent period.

(Feinendegen, 2010).

Net Result: There would be less DNA damage and mutations following low radiation exposures, as observed in studies of fruit flies (Koana, 2010) and in mice (Osipov, 2013)

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Do Cancers Increase with Mutations?

Mutations accumulate at the highest rates during the period of growth at young age, when most cell divisions are taking place. However, cancers occur at the lowest rates during young age (DeGregori, 2013). For humans also, cancers occur at the lowest rates at young age.

Cancers do not increase with mutations.

Therefore, the two concepts underlying the LNT model have turned out to be incorrect. There is no radiobiological justification for the LNT model.

Mutations are not sufficient to cause cancer. Some other factor causes cancer later. What is this factor?

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Importance of the Immune System in Preventing Cancer

Cancer risk increases drastically with the suppression of the immune system in organtransplant patients (Acuna, 2016) and HIV patients (Simard, 2012)

The tremendous increase in cancers when the immune system is suppressed indicates suppression of the immune system may be the primary cause of most cancers.

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Explanation for the Increase in Cancers with Age

Immune system response declines rapidly with age (Levin, 2012)

Cancer risk rises rapidly with age (WHO).

The decline of the immune system with age provides a possible explanation for the rise in cancer risk with age.

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The Effect of Low-dose Radiation on the Immune System

Low-dose radiation boosts the immune system (Yang, 2014) and so it should lead to reduction of cancers, a phenomenon known as radiation hormesis.

Thus, there is justification for radiation hormesis from radiation biology 10 but no justification for the LNT model.

The BEIR VII Report published in 2006 by National Academy of Sciences missed noting the importance of the immune system in preventing cancers and the stimulating effect of low-dose radiation on the immune system (Liu, 2003). Instead they paid attention to DNA damage and mutations as the cause of cancers, and we have seen that this concept is not supported by evidence.

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Evidence Against the LNT model or for Radiation Hormesis

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Evidence Against the LNT model or for Radiation Hormesis

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Most of the evidence shown in the last two slides predated the BEIR VII Report by National Academy of Sciences. However, the BEIR VII Report did not use any of these evidence.

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Evidence Quoted by BEIR VII Report to Support the LNT Model

Error bars were not shown in the publication but are large and the data would be consistent with many different models. The update to the data (Ozasa, 2012) has significant non-linearity (curvature) that is in inconsistent with the LNT model (as seen in the next slide).

The significant excess relative risk was primarily due to the Canadian data. CNSC withdrew the Canadian data citing major problems with the data (CNSC, 2011).

Without these data, the 15-Country study would no longer show significantly increased cancer risk in the radiation workers.

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Atomic Bomb Survivor Data are Inconsistent with the LNT Model •A linear no-threshold dose-response shape was assumed in the analysis of the data to extract the Excess Relative Risks (Ozasa et al, 2012).

(Instead, they should have used a J-shaped doseresponse curve, based on evidence).

•The publication reported significant curvature in the dose-response relationship that they stated was not explainable.

•As colon dose increases from 0.25 Gy to 0.5 Gy, cancers decrease, contradicting the LNT model.

•Large curvature in dose-response contradicts the LNT model (the linearity part).

Atomic bomb survivor data are inconsistent with the LNT model.

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Evidence for Radiation Hormesis in Atomic Bomb Survivor Data Ozasa et al. utilized the lowest radiation dose data (extrapolated to zero dose) as the baseline cancer rate in the process of extracting the Excess Relative Risks.

Since low radiation exposures would reduce cancers (as seen in earlier slides), baseline cancer rates used would have a negative bias.

The shape of dose-response, with the correction for the negative bias in the baseline cancer rate (Doss, 2012), (Doss, 2013), is consistent with radiation hormesis.

In atomic bomb survivor data, low radiation doses reduce cancers.17

Evidence Quoted by NCRP to Support the LNT Model The recent NCRP Commentary 27 (May 2018) which endorsed the LNT model stated that the following studies provide strong evidence for the LNT Model

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Cancer Incidence in Atomic Bomb Survivors (Grant, 2017) •

•

•

• •

The authors concluded, as stated in their abstract: “At this time, uncertainties in the shape of the dose response preclude definitive conclusions to confidently guide radiation protection policies.” This is not support for the LNT model, and definitely not strong support for the LNT model.

The analysis of the cancer incidence data has the same issue that was mentioned with respect to the cancer mortality data of Ozasa et al. a few slides back, that they used a linear dose-response function in order to extract Excess Relative Risks (ERRs) while all the evidence points to a J-shaped dose response.

The curvature in dose-response for these data (for Colon Dose 0-2 Gy) has also increased with the longer follow-up period and has become significant (P=0.002).

The significant curvature in these data are inconsistent with the LNT model, in a manner similar to that noted for the Ozasa et. al. cancer mortality data.

The (Grant, 2017) publication does not provide support for the LNT model. 19

INWORKS - Study of Nuclear Industry Workers in USA, UK, and France during 1945-2005 • The (Richardson, 2015) study reported, for all solid cancers, ERR/Gy = 0.51 (0.23-0.82, 90% CI) Note: Smoking rates declined drastically between 1940s and 2000s. Smoking increases risk of many cancers.

• Most of the higher occupational doses were in the earlier years, when higher smoking rates would have led to increased cancer risk.

• Notwithstanding this major confounding by smoking, INWORKS study reported results without correcting for smoking • The article stated that with smoking related cancers (70% of the cancers) excluded, ERR/Gy = 0.37 (−0.14 to 0.95, 90% CI)

Therefore, if smoking-related cancers are excluded, there is no significantly increased ERR/Gy in the irradiated cohort.

INWORKS study does not provide evidence for the LNT model.

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Breast Cancer Risk in Massachusetts TB Patients that Underwent Fluoroscopic Examinations (Little and Boice, 2003) (Davis, 1989) is a publication on the same cohort.

SMR (Breast Cancer) = 1.4 (1.05-1.75 95% CI) Significant increase, but SMR (All cancers) had a Significant decrease ďƒ¨ While breast had high radiation dose, other parts of the body likely received lower doses resulting in hormetic reduction of cancers in other parts of the body and overall cancers.

Examining only breast cancer risk would have misrepresented the overall health consequence of the irradiation, since it would have ignored the reduction in other cancers and all cancers.

In a similar manner, the (Little and Boice, 2003) study misrepresents the cancer risk from the radiation exposures by focusing on breast cancer only.

(Little and Boice, 2003) data do not support the LNT model.

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Questionable Actions of Advisory Bodies • We have seen that the first three studies that were claimed to provide strong support for the LNT model by NCRP do not support the LNT model at all.

• A close examination of the other studies that NCRP claimed supported the LNT model would show that none of them support the LNT model.

• In addition, NCRP ignored a large number of publications that show evidence against the LNT model and for radiation hormesis.

• Such actions by advisory bodies should be questioned.

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Conclusion Regarding the LNT Model

.Vs

Strong evidence for LNT,

Evidence against LNT and for Radiation Hormesis

according to NCRP (But it is confounded by smoking)

Conclusion: The LNT model is not valid. There appears to be no valid evidence to support it. There is plenty of evidence for the cancer preventive effect of low-dose radiation.

LNT model is still in use due to questionable actions by advisory bodies.

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Benefits to the Public from Using the LNT Model

Is there any benefit to the public from using the LNT model and reducing radiation dose when they are already at low levels?

All the evidence indicates that reducing dose at low doses, e.g. from 50 mSv to 1 mSv, would increase cancer risk.

Therefore, there would not be any benefit to the public from the use of the LNT model and keeping doses as low as reasonably achievable, or ALARA, but there may be detriment.

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Harms From the Use of the LNT model •Diagnostic imaging (wasted time and resources due to excessive regulations, dose reduction efforts may result in poorer quality images, patients/parents may refuse scans, they may have concerns regarding scans) •Nuclear power (fear of low-dose radiation has suppressed nuclear power, ratcheting up of regulations has made it economically not viable even though it is the safest and cheapest mode of reliable power generation) •Nuclear reactor accidents (unnecessary evacuations wrecked the lives of hundreds of thousands of people in Chernobyl and Fukushima and caused large casualties.)

•Cancer and neurodegenerative diseases (fear of low-dose radiation blocked the study of low-dose radiation for prevention of such diseases in spite of evidence showing low-dose radiation would have a preventive effect.)

See the website of XLNT Foundation for more details: https://www.x-lnt.org/harms-from-the-use-of-the-lnt-model 25

Harms From the Use of the LNT model The LNT Model and the radiation safety principle to keep the radiation doses as low as reasonably achievable (ALARA) blocked the study of radiation hormesis in the 1980s when it was proposed as a method of reducing cancers (Hormesis with Ionizing Radiation, TD Luckey, 1980).

•Studying radiation hormesis in the 1980s would have shown a 20-30% reduction in cancer mortality rates (as seen in earlier slides) •This would have led to the worldwide adoption of radiation hormesis •If we assume conservatively that there may be a 10% reduction in cancer rates from the use of radiation hormesis worldwide, the LNT model may be responsible over 2000 preventable cancer deaths every day in the world (Doss, 2014)

Those who support the LNT model should consider such consequences and stop supporting the LNT model.

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Who Benefits from the LNT Model?

LNT model has led to many enterprises that address low-dose radiation concerns including monitoring and measurement of radiation dose, dose reduction efforts, and research on these subjects. It has also led to enterprises that work on low-dose radiation regulations, guidelines, compliance, etc.

There is plenty of economic benefit from these activities. The beneficiaries include scientists, advisory bodies, regulatory agencies, government departments, professional organizations, accrediting bodies, healthcare organizations, etc.

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Why are we still using the LNT model?

• Governments, regulatory agencies, professional organizations, etc. take guidance from the advisory bodies and would not stop using the LNT model until the advisory bodies change their recommendations.

• Advisory bodies have ignored the evidence for radiation hormesis and have accepted faulty publications supporting the LNT model.

• Regulatory agencies have tremendous power enforcing the LNT model based regulations.

• Popular press gives plenty of free publicity to faulty LNT model supporting publications and faulty advisory body reports but gives little publicity when such publications are debunked.

• The beneficiaries of the LNT model are in powerful positions, the opponents have no power.

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Signs of Progress Towards Ending the LNT Era •Three Petitions to discard the LNT model were filed with NRC in 2015 and are still under consideration.

•Health Physics Society modified its Position Statement in 2016 stating its opposition to the LNT model and recognizing adaptive response.

•Mainstream publications are beginning to publish articles opposing the LNT model, e.g. (Siegel, 2018) in JNMMI challenging the BEIR VII Report. The author list included the past SNMMI president and a former SNMMI President.

•Mainstream websites are opposing the LNT model, e.g. RADAR •Upcoming ANS-HPS Topical Meeting on Dose-Response Models (Oct 2018) 29

How to Hasten the End of the LNT Era? (An Opinion) The advisory bodies have shown by their recent actions that they would not correct themselves even though there is overwhelming evidence against the LNT model.

A change in the scientific leadership and membership of the advisory bodies is necessary. New leadership and members should be appointed who are willing to consider all evidence before drawing conclusions.

If the advisory bodies do not voluntarily change in this manner, we need to defund the current advisory bodies and create new ones with a better approach to the issue.

Your suggestions are welcome.

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What You Can Do to Help End the LNT Era • Visit websites of organizations that are working to overcome the LNT model problem. Become familiar with the issues.

• Join and/or support the organizations working against the LNT model.

• Study the evidence for low-dose radiation health effects. Reject faulty evidence.

• Question professional organizations and advisory bodies when they utilize the LNT model for guidance.

• Express your support to end the LNT model Era (social media, articles, etc.)

Organizations that are working to end the LNT era • International Dose-Response Society http://dose-response.org/ • Scientists for Accurate Radiation Information (SARI) http://radiationeffects.org/ (Mohan Doss is one of the founding members) • XLNT Foundation https://www.x-lnt.org/ (Mohan Doss – President) • RADAR - the RAdiation Dose Assessment Resource http://www.doseinfo-radar.com/

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Summary and Conclusions • LNT model was adopted by advisory bodies without any supporting data.

• LNT model is justified based on the concepts that even a small amount of radiation increases mutations, and increased mutations imply increased cancers.

• These concepts are not valid. Low-dose radiation boosts defenses and so would result in reduced DNA damage and mutations. Suppression of the immune system is the primary cause of most cancers. Low-dose radiation boosts the immune system, and so would reduce cancers.

• There is plenty of evidence for radiation hormesis and against the LNT model, including the Atomic Bomb Survivor Data.

• Publications supporting the LNT model have major flaws.

• Many major adverse consequences result from the use of the LNT model: in diagnostic imaging, nuclear power, war on cancer, etc.

• Reason for the LNT model era – advisory bodies, since they have ignored evidence for radiation hormesis, and have accepted faulty evidence.

• In my opinion, we need to change the composition of the advisory bodies, as they would not change their current support for the LNT model.

• Ultimately, the LNT era will end. There are some hopeful signs, and the efforts to end the LNT era continue. Your ideas, suggestions, and help are needed.

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