Biological Theory has published the equivalent of a “bunker buster” salvo in a decades-long war of words between scientists.
On one side are people who believe that there is no safe dose of radiation. They assert that radiation protection regulations should continue using a linear, no threshold model.
The other side includes those who say that sufficient evidence has been gathered to show there are dose levels below which there is no permanent damage. They say the evidence indicates the possibility of a modest health improvement over a range of low doses and dose rates. They believe that the LNT model is obsolete and does not do a good job of protecting people from harm.
The new paper has the reverse-click bait title of Epidemiology Without Biology: False Paradigms, Unfounded Assumptions, and Specious Statistics in Radiation Science (with Commentaries by Inge Schmitz-Feuerhake and Christopher Busby and a Reply by the Authors).
It has characteristics that make it unusually important.
- Two of the paper’s reviewers voluntarily gave up their using anonymity and agreed to have their comments published with the paper
- The paper authors addressed the reviewer comments
- It identifies specific fallacies in the “no safe dose” theory
- It does not include any equations or obscure mathematics
- It has been published as an Open Access paper with a Creative Commons Attribution 4.0 International License
- The journal editors allowed a major exception to their normal word limit as a result of their judgement about the topic’s importance
For people who aren’t in the fields of radiation protection, nuclear medicine or nuclear energy, the debate about the proper basis for the regulatory model for low level radiation might seem to be an obscure scientific or political conflict. Some who are in the affected fields believe that the science was long ago settled, the appointed committees have made their decision and it is too late to change existing public perception.
Bill Sacks, Gregory Meyerson and Jeffry A. Siegel, the authors of the bunker-buster of a paper, believe it’s never too late for an evidence-based discussion that results in a revision of our current paradigm.
They understand that a revision away from the “no safe dose” assumption would have financial implications measured in the tens to hundreds of billions of dollars per year. There are tens of thousands of affected jobs and many thousands more that might be created or destroyed depending on the outcome of the discussion.
Here is what they say about the implications of a move away from the LNT assumption.
Belief in LNT informs the practice of radiology, radiation regulatory policies, and popular culture through the media. The result is mass radiophobia and harmful outcomes, including forced relocations of populations near nuclear power plant accidents, reluctance to avail oneself of needed medical imaging studies, and aversion to nuclear energy—-all unwarranted and all harmful to millions of people.
Primary Theme Of New Paper
According to Sacks et al, the main reason for the continued dominance of the “no safe dose” assertion is that there have been hundreds of papers published that treat detection of the effects of low dose radiation as an epidemiological issue in isolation from a biological science.
As they explain the situation, studies of exposed people that attempt to make risk judgements based on reported disease incidence have often started with assumptions that radiation is a proven carcinogen, that there is no expected threshold and that a study finding no detectable harm simply has an insufficient statistical power to detect a small signal. Unsurprisingly, studies that begin with an underlying assumption that the damage is directly proportional to the dose all the way to zero end up with results that can be described as “consistent with” that model.
At its root, the linear no threshold (LNT) model is based on the “target theory” that reduces biological organisms to individual molecules that are passive receivers of radiation. Under this paradigm, there is no interactions between molecules, no evolved responses to damage, no mechanisms for recovery and no system that rejuvenates or eliminates faulty tissues. Sacks et al call this “a particular form of reductionism.”
The LNT for genetic damage was introduced to the world on June 12, 1956 and was extended to cancer initiation in 1957. Since then there has a vast increase in our understanding of DNA and cancer development that is not reflected in the model.
It must be noted that the vast majority of human cancers are not simply the end product of one or more mutations. Such mutations may be necessary, but they are not sufficient to produce cancer. The 2015 Nobel Prize in Chemistry went to three investigators—Lindahl, Modrich, and Sancar—for discovering three intracellular repair mechanisms that prevent most of us from getting cancer on a regular basis. In addition to intracellular DNA repair mechanisms, modern understanding of the role of the immune system in the development of clinically overt cancers has led to a replacement of the outdated “one mutation = one cancer” model. In fact, deficiencies in repair enzymes and/or evasion from immune system detection and destruction have emerged as the newest explanations for cancer formation, rather than simply DNA damage.
Sacks, Meyerson and Siegel take on the primary US regulators (NRC and EPA), the National Academies of Science Biological Effects of Ionizing Radiation committees, the Image Gently campaign and a number of recently published papers by LNT defenders that have been cited by numerous sources as providing continued “proof” that the LNT is the best available model.
They point out that papers based on statistical inference have been getting a lot of negative attention in medical journals recently and explain why many of the radiation health epidemiological share the weaknesses that have been identified in so many similar fields.
They describe how career and financial investments in the LNT have increased the resistance to having a serious discussion of the biological evidence that disputes the model.
They don’t mention, but I will, the fact that the US Department of Energy invested in a low dose radiation research program for ten years, but funding for the program was abruptly cut off just as many of the studies were being completed. Those studies were approaching a conclusive demonstration of the existence of safe doses because of the way biological systems can protect, respond and repair themselves.
Sacks, Meyerson and Siegel conclude their essay with a discussion of three examples ways that continued adherence to a biologically inaccurate “no safe dose” assertion is harmful to humanity.
- It has led to unnecessary, forced relocations of hundreds of thousands of people at Chernobyl and Fukushima
- It leads people to refuse useful medical imaging, sometimes substituting far more risky and invasive alternatives
- It contributes to the aversion to nuclear energy
This paper deserves attention and study. The possibility of revising the radiation paradigm to acknowledge that low doses of radiation are safe is too important to ignore.
Disclosure: Like the three authors of the paper discussed, I am a member of SARI – Scientists for Accurate Radiation Information. I contributed when the hat was passed to raise the funds that would enable the paper discussed to be published as Open Access.
The above article was initially published with the headline Powerful Shot Against Believers In “No Safe Dose” Of Radiation on Forbes.com.