Why does conventional wisdom ignore hormesis?
By Bill Sacks and Greg Meyerson
What we are about to say flies in the face of the conventional wisdom. There is no automatic reason for anyone to believe or trust our comments, so we provide some sources at the end that allow the reader to do further investigation. And for the sake of brevity we will for the most part make categorical statements, claims which rest on voluminous evidence that the reader may have to study, just as we have done, in order to get over the speed bump that the conventional wisdom invariably represents. Therefore consider this an introduction to the topic of radiation “hormesis,” intended to open doors, rather than an attempt to convince–-an impossible goal of a single commentary, particularly under the circumstances.
Hormesis – the stimulation by some agent, such as radiation, of biological responses that are protective against damage done by that agent. It has the same etymological root as hormone, which is a molecule secreted by a gland to stimulate a response in some other part of the body.
The biological response of people (as well as other animals and plants) to ionizing radiation (the kind produced by nuclear processes and x-rays or CT scans) is one with three phases:
- the response to too much radiation,
- to a healthy amount of radiation
- to a radiation deficiency
The second of these is the one that involves the protective response. In light of repeated assertions that all ionizing radiation is harmful no matter how high or how low the dose, the existence of a beneficial health effect may be surprising. But nearly a century of laboratory experimentation and epidemiological observation of both humans and animals supports the protective response region and contradicts the conventional wisdom. Why then does the concept that all ionizing radiation is harmful hang on with such tenacity, and how did it gain a foothold against all evidence to the contrary?
In the early part of the 20th century, radiation (for convenience we will drop the word “ionizing” but it should be understood for the purposes of this commentary) regulations by government agencies–regulations which were recommended by certain research organizations, but not all–allowed exposures to much higher doses of radiation than became the rule after the dropping of the “atomic” bombs on Hiroshima and Nagasaki in August 1945.
The arms race that followed the war, especially between the US and the Soviet Union, gave rise to the testing of more and more nuclear weapons. At first this testing was in the atmosphere. Open-air testing released radioactive materials from the explosion that were massively diluted and carried by the wind to distant places. The material included radioactive fission products as well as the original uranium or plutonium that constitute the initial explosives. Doses and dose rates caused by exposure to this material were, with very few exceptions, tiny. Scientists responsible for public health protection computed that there was no risk to the public from such small exposures.
A campaign began to stop the testing of nuclear weapons in the atmosphere. Scientists who recognized the dangers of nuclear war wanted to convince masses of people to protest their respective governments against both the testing of nuclear weapons and the nuclear arms race. In pursuit of this goal, they were willing to lie about the dangers of fallout and exposure to low or moderate amounts of radiation from radioactive material. Many of the scientists involved in the political effort to slow the arms race and halt testing were involved in the Manhattan Project and expressed regrets for their participation in the creation of nuclear weapons because of the death and destruction caused by the use of bombs at Hiroshima and Nagasaki.
The first recorded lie in this campaign was offered in 1946 by Hermann Muller as part of his acceptance speech for the Nobel Prize he received for his earlier work on radiation-caused mutations in fruit flies. He claimed there was unequivocal evidence that all radiation was harmful and proposed the theory that individual “hits” produced mutations, but his statement has often been repeated out of context. Here is a more complete quote:
These facts have since been established with great exactitude and detail, more especially by Timoféeff and his co-workers. In our more recent work with Raychaudhuri (1939, 1940) these principles have been extended to total doses as low as 400 r, and rates as low as 0.01 r per minute, with gamma rays. They leave, we believe, no escape from the conclusion that there is no threshold dose, and that the individual mutations result from individual “hits”, producing genetic effects in their immediate neighborhood.
Even though he provided some caveats and context, Muller was in possession of information that he knew disproved the assertion. One of his colleagues had just obtained an experimental result showing that low doses of radiation actually were protective, which Muller had acknowledged one month prior to his acceptance speech, saying in a note that when he returned from Stockholm they would have to look into this further. (Ref: Callabrese, Edward, Muller’s Nobel lecture on dose–response for ionizing radiation: ideology or science?, Archives of Toxicology, Dec. 2011).
Muller was thus the first to deliberately exaggerate the dangers in order to create a climate of fear. This lie, this exaggeration, is still with us to this very day, and pervades the underlying position of virtually all governmental regulatory agencies around the world that deal with radiation – as well as the position of those economic interests (particularly fossil fuel companies), organizations, and individuals opposed to nuclear energy.
The lie became embodied in a demonstrably false expediency that is called the linear-no-threshold (LNT) model, which states that damage due to radiation is harmful and linear down to zero dose, with no threshold below which there is no harm. Linear means that, for example, twice as much radiation, no matter how low the dose, creates twice as much damage to a population, mainly in the form of numbers of cancers and deaths. The absence of a threshold is sometimes admitted by advocates of LNT to be a mere expediency. This is particularly true of the series of reports published by the BEIR (Biological Effects of Ionizing Radiation) committee of the National Research Council (part of the National Academy of Sciences).
But rather than announcing that there is no evidence to support this model, LNT advocates, including the BEIR committee, assert that in order to demonstrate that LNT is true, the sample sizes of people exposed to low doses would have to be impractically large for statistical significance to be obtained. This incidentally argues, without their intending it, that any statistical significance so achieved would indicate very little clinical significance in the low-dose range if LNT were true.
They even go so far as to claim that the actual data in the low-dose range are “consistent with” LNT. This latter claim rules out hormesis a priori, so that evidence that is far more “consistent with” hormesis (as the sources mentioned at the end, both directly and indirectly, will testify) is ignorable as such, and is co-opted to their purposes with the statement that the evidence is “inconclusive.” In short, they rule out hormesis by fiat rather than by scientific evidence. They are forced to this maneuver since the evidence supports hormesis and contradicts LNT. The only reason that LNT is widely accepted is that virtually all political power stands behind LNT, so that it has long been the default position. This is not science.
But more recently a growing group of researchers into the effects of radiation at various doses, and others who support their efforts, have begun campaigns to undo the very harmful effects of the radiophobia–-an unwarranted fear of radiation–that has arisen from insistence on the LNT assumption. The media and certain publicists stoke radiophobia because “fear sells.” There are even scientists who seek the prominence that opposition to radiation earns them.
Radiophobia not only fails to prevent harm, but actually causes harm–and very great harm at that. First, it produces a refusal by many people to undergo potentially life-saving radiation, from things like x-rays and CT scans to nuclear medicine studies, for the purpose of diagnosing illnesses and injuries–illnesses such as breast cancer that can be detected on mammograms early enough to cure it and injuries such as traumatic brain injury (TBI) caused by head impacts.
Second, and perhaps even more devastating, radiophobia produces government-sponsored forced evacuations of entire areas surrounding nuclear plants that experience accidents, as happened around Chernobyl (in Ukraine) in 1986 and around Fukushima in 2011. Only the accident at Three Mile Island near Harrisburg, PA, in 1979 failed to produce such a reaction by the government, though entirely unwarranted fears were still fanned among nearby residents. The consequences of forced evacuations of hundreds of thousands of people have resulted in destruction of homes, communities, and jobs, and contributed to alcohol abuse, suicides, unwarranted abortions, and other pathways to early death. Children of families who were forced to relocate by the Japanese government have been shunned by their new schoolmates out of an unfounded fear that they are radioactive–-a stunning result of pronounced disinformation and misinformation by the media and government.
In contrast, the radiation has hurt no one, in either location, with the sole exception of the firefighting personnel who put out the 10-day fire at Chernobyl from helicopters and were exposed to massive doses of radiation coming out of the smokestacks. While it has been claimed that there was an increase in the rate of thyroid cancer incidence in children following the nuclear meltdowns in both Chernobyl and Fukushima, there is evidence even in the more plausible instance of Chernobyl that this putative increase may be an artifact of the new onset of screening.
There was no baseline measurement of the rates of such cancers prior to either accident, so any claim of an increase is unfounded, especially in the case of Fukushima. The intense screening for thyroid cancer that has taken place in and around these locations has led to the discovery of high rates of occult thyroid cancers in both children and adults that were previously unsuspected. Since the latency period for the development of thyroid cancer is at least 4 years, any such finding around Fukushima must necessarily be part of the baseline and cannot possibly be the result of radiation from the nuclear plant, as anti-nuclear propagandists would like us to believe.
And if it should prove some day that even a part of the increase around Chernobyl was indeed contributed to by the radiation, it should be noted that the paucity of iodine in that geographical area-–as opposed to Japan, where the diet is rich in iodine-–leaves thyroid glands excessively hungry to take up any and all iodine that becomes available, particularly the radioactive I-131 emitted by the nuclear plant. It should also be noted that any uptake of I-131 can always be blocked through the administration of non-radioactive iodine in the form of potassium iodide tablets, as was done around Fukushima.
LNT leads to the setting of excessively low radiation exposure limits by various regulatory agencies around the world, such as the US Environmental Protection Agency (EPA). Such limits do not “err on the safe side,” as many who work for these agencies try to console themselves, but rather cause tremendous harm to millions of people.
Radiation is like virtually every other agent, whether physical, chemical, social, or psychological. There can be too much, just right, or too little. Everyday examples include water, oxygen, sunlight, and exercise. Too much water and electrolytes become diluted resulting in cardiac arrhythmias; just right keeps the body well hydrated and allows chemical reactions to proceed as needed; and too little results in dehydration and death. Too much oxygen results in oxygen toxicity with effects such as blindness and disorientation; just right keeps us breathing; and too little leads to suffocation and death. Too much sunlight leads to sunburn and skin cancer; just right keeps vitamin D levels in a healthy range; and too little leads to rickets with its bone deformities in children (unless vitamin D is supplemented through diet). Too much exercise can result in muscle damage or heart attacks; just right keeps one fit; and too little leads to obesity and lethargy, with muscle wasting and weakness.
In fact, as recent research shows, the interaction of proper levels of exercise with cell dynamics is in certain ways almost identical to the interaction of radiation in the hormetic zone with cellular mechanisms that both repair and improve cell function. Both exercise and radiation at appropriate levels cause damage, sometimes in the form of double-strand breaks of DNA, that subsequently stimulates mechanisms that repair those breaks, along with other breaks caused by oxidative stress. The latter outweigh those caused by radiation by several orders of magnitude, even when we are at rest. See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036399/).
Examples of hormesis are thus widespread, but the point is that there is a so-called “goldilocks” zone of “just right,” as well as two peripheral zones of “too much” and “too little” for all these agents. And radiation, as we note, is no exception. The amount of natural background radiation from place to place on earth varies by a factor of over 200 to 1 – due largely to the radioactive element radon (a gas) that seeps from the ground, as well as to significantly varying amounts of radium and thorium near the surface of the ground. Those places with the very highest natural radiation levels–including parts of Iran, Finland, India, and Brazil, among others–have healthy people with no higher rates of cancer, and often lower rates, and no earlier deaths, and often longer lives.
All agents to which the earth’s environment has exposed bacteria, fungi, plants, and animals, as they have evolved over hundreds of millions of years, have necessarily produced organisms that are resistant to harms done by those agents. It is important to note that the rash of new chemicals in our modern environment–some thousand new chemicals each year–have not been around to produce such selective pressures. As a result, we are susceptible to injuries and illnesses from them, prominently including cancer and heart disease. Against such agents we have not had a chance to develop defenses, a development that can take hundreds to thousands of years. Thus some of these new agents may very well be harmful regardless of how low the dose, and should–like lead and mercury–be regulated differently from those exhibiting a hormetic effect.
While this essay is too brief to document the evidence for hormesis, we refer below to some of the best sources that should lead the open-minded reader to rethink her/his assumptions. But we would like to present readers with one important piece of research, important precisely because the investigator expected the opposite of what he found.
Bernard Cohen of the University of Pittsburgh did a massive 4-year study in the early 1990s of radon levels in homes versus lung cancer rates. He investigated over 1700 US counties that included more than 90% of the US population. Believing the demonstrably false LNT model to be true, he expected to measure the rate at which lung cancer rates increased as radon levels in homes increased. But instead he found the opposite, namely that those counties with the higher levels of home radon were those with the lower rates of lung cancer, and vice versa. Not ready to believe this result, he examined with the help of a statistician hundreds of combinations of possible confounders, but none of them could explain the results. He was therefore driven to conclude that radon is actually protective against lung cancer–even in smokers–within the ranges found in US homes. See figure below:
Focusing on the region below about 1 pCi/l (picocuries per liter of air) of radon reveals that not only is radon protective above 1 pCi/l, within the limits measured, but that inadequate amounts of radon permit an excess of lung cancers. By stressing the fact that it is possible to be exposed to too little radiation (as suggested in our third bullet at the beginning of this commentary), it may be possible to overcome the influence of the decades-old falsehood that all radiation is harmful. It is not simply harmless at low doses, but it is actually beneficial – at least in the goldilocks zone – unless the level is too low.
Radiologists, for example, who have been assiduously trained in the LNT model, justify their exposing patients to radiation for needed imaging studies by comparing the risk of refusing a screening mammogram, x-ray, or CT to the risk of cancer and early death from undergoing such studies. Since the benefit of diagnostic information always outweighs the risk of negative consequences, radiologists have not been forced-–yet-–to relinquish their professional hold on LNT. Though a handful are coming to realize that LNT has other severely negative consequences and are beginning to try to convince their fellows of this reality. In contrast, many of the world’s scientists who investigate the biological effects of low doses of radiation have already come to this conclusion and have been trying to introduce this by now counterintuitive concept to the field of radiology-–so far to little avail.
The LNT falsehood not only fails to “err on the safe side,” but it is harmful, as it causes devastating actions like forced evacuations of homes and communities while inhibiting, or actually preventing, access to life-saving and health-conferring radiation, whether diagnostic or therapeutic. Further, by helping to spread unwarranted fears, it impedes our capacity for rational thought.
As such, adherence to LNT by regulatory agencies and organizations may rightly be considered criminal. As Gunnar Walinder, former chairperson of the Swedish Radiobiology Society and author of the book Has Radiation Protection Become a Health Hazard (2000), has put it, “LNT is the greatest scientific scandal of the 20th century.”
We would note that the greatest harm facilitated by the LNT falsehood is that its affiliated and entirely fictitious metrics for estimating future mortality have enabled an anti-nuclear paradigm rooted in fear. This has worked to disable our most reliable technology for addressing climate change, even as it promotes fantasy-laden optimism about the scalability of inherently intermittent and dilute wind and solar to carry the burden of baseload electricity.
We conclude by declaring that we have no connection to the nuclear industry, to any grant-funding agency, or to any other business or governmental agency involved in radiation regulation or related issues. Our only interest is in promulgating the scientific truth as an antidote to official unscientific falsehoods that do benefit some, both financially and socially.
Since this commentary flies in the face of the conventional wisdom, we suggest some sources for further investigation. Everyone will need to convince her/himself, just as we have, through some reading. Try beginning with such overviews as T.D. Luckey’s book Radiation Hormesis (1991) or Charles L. Sanders’s book Radiation Hormesis and the Linear-No-Threshold Assumption (2010), both of which, in turn, cite hundreds and hundreds of scientific studies from around the world for further follow-up.
About the authors:
Bill Sacks is a physicist turned radiologist who is now retired. He has spent the past few years studying global warming, nuclear energy, and the beneficial biological responses to low level ionizing radiation. He has coauthored a number of articles including Nuclear Energy: The Only Solution to the Energy Problem and Global Warming.
Greg Meyerson is a specialist in critical theory and is a professor in the English department at North Carolina A&T. He teaches STEM oriented advanced composition for the College of Arts and Sciences at North Carolina A&T. He has coauthored a number of articles including Nuclear Energy: The Only Solution to the Energy Problem and Global Warming
Editor note: Atomic Insights has been following the effort to uncover the history associated with implementation of the LNT assumption as the basis for radiation protection regulations for several years. Until recently, we accepted the idea that Muller was motivated by a sincere and admirable desire to limit halt the arms race and nuclear weapons testing. Recently, we discovered that Muller’s fruit fly experiments between 1927-1932 were generously supported by grants from the oil and gas-linked Rockefeller Foundation. Muller’s later work at Indiana University was also generously supported by the same foundation.
This discovery has raised serious questions about Muller’s true motivations for a long history of spreading fear, uncertainty and doubt about the danger of radiation, even at very low doses and dose rates.
Apologies, Rod. Just noted the authorship. Criticism and praise stands, albeit not intentionally misdirected.
All good, up to the point of connecting Muller to Oil … that is a stretch, and harms the persuasiveness of this piece.
How is it a stretch to note that Muller’s research was funded by Rockefeller Foundation for several decades? Though it can be argued today that the foundation has evolved far past its oil wealth roots, that statement would have been ludicrous in 1927 or even 1950s when it was still heavily influenced by Rockefeller Brothers Fund and Rockefeller “Family Office” management.
For me the only stretch is because in 1927, Standard Oil would not be threatened by Nuclear Energy.
I agree with your ongoing perspective that oil, gas, companies now know that Nuclear Energy is the only true challenger to their revenue streams, and want sunshine and breezes, to be their competition instead of Nuclear.
In 1927? It can’t be.
I agree. Prospects for nuclear energy were mere fantasy until late 1930s. Suggesting the rockefeller fndtn would support dodgy science for anticompetitive reasons is pushing the argument too far. I cant agree with that at all. Once the threat was clear -I can buy that possibility. Heck that is normal business
Standard Oil was always run by people who kept fully abreast of any technical developments in their field of supplying energy. They made enormous capital investments and needed to understand everything they could about demand and supply long into the future.
The earliest mention of “atomic energy” that I found in a quick search of the New York Times archive (which has often been called the USA “paper of record”) was published on September 9, 1921, several years before Muller began his study of the effects of radiation on fruit flies.
The article, titled “Chemists Predict a Startling New Era: Sun’s Rays, Earth’s Rotation, and Atomic Energy in Matter To Be Used” was a report of a meeting of the American Chemical Society. It included the following quote:
In 1921, radium was one of the most valuable substances ever isolated, carrying a price of $120,000 per gram. That number is in nominal, “then-year” dollars, with no attempt to account for the inflation that has occurred since then.
By 1930, the World Energy Congress was treated to a keynote address in which Sir Arthur Eddington made the following memorable prediction:
I’m still looking for the full text of that speech, but that quote still appears in the summary history of the World Energy Council.
Nuclear power was not taking any markets yet from coal or oil, but there were certainly people at Standard Oil who were savvy enough to begin investing in learning more about a potential competitor, especially if they could discover any weaknesses that could be used in later marketing campaigns.
It’s not about oil. It’s about petro-dollars.
Why does conventional wisdom ignore hormesis?
For the same reason conventional wisdom ignores homeopathy.
They’re both pseudo-science.
I used to actually somewhat enjoy your appearance in the comment threads here. However, lately you have done nothing beyond a simply hit-and-run on any relevant-to-you post, with almost no follow-up discussion (outside of your clarification regarding the Studsvik (sp?) sale/purchase of RACE, I forget the precise details).
I would like to see you actually engage in some discussion rather than only commit drive-by’s.
It’s clear you’ve mastered the peer-reviewed science, bob. I am going to ignore you.
You say “Also, I wonder if in fact the amount of people whose fear of radiation causes them to refuse diagnostic or curative radiation treatments may be exaggerated here by insinuation. Personally, I know many people that fear radiation, but I can think of no one I have ever met whose fear has caused them to refuse x-rays, or radioactive cancer treatment.”
Assuming that you have not dealt with a hundred thousand women and more about screening mammograms, as I have, your experience with this might be somewhat limited. It has been the case, at least in the not too distant past (I haven’t kept up with the more recent statistics), that one-third of all eligible women received screening mammograms every year, one-third had gotten at least one at some time in the past, and the final one-third had never gotten one. There are very few, if any, internists who fail to recommend a yearly mammogram for women over 40. Therefore, if 2/3 of women over 40 in the US fail to get one every year, it is not much of a stretch to imagine that radiophobia plays a significant role — even if there might be other inhibiting considerations, including cost and lack of insurance.
The rest of my experience is anecdotal, but I can assure you, and the other readers, that this is just as significant a problem as the increasingly common refusal of parents to have their children vaccinated. The latter is based on a very similar unwarranted and exaggerated fear of vaccines that was vaulted into prominence by Andrew Wakefield’s fraudulent claim in 1998 that vaccines cause autism, for which fraud his medical license was taken away by the UK.
Lies like LNT and vaccine-linked autism do tremendous harm in the health care field, and operate largely through people’s susceptibility to phobic responses to mountains of disinformation.
And thanks for the laudatory aspect of your note. 🙂
I have to agree with the Rand fan here. Bill’s argument is kinda like saying that people avoid colonoscopies because they have an irrational fear of cameras.
I have refused a CT scan that was going to dose me with 22 mSv, about 10 years of my background.
I did take a few one shot chest Xrays, I asked the technician how much radiation the CT be be, he said, I don’t really know but it something like flying on a airplane.
They only get taught the trite lies, not real data.
Blood test which was known to be available in 24 hours did in fact negate the need for the CT.
this is not fear, this is knowledge and suitable caution and prudence.
I found this:
“In addition, the fear has been the basis of mass relocations in the vicinities of Chernobyl and Fukushima that are wholly unnecessary as far as the possibility of physical harm is concerned but that cause untold amounts of psychological harm, with consequent alcoholism, voluntary abortion, depression, stress-related heart attacks and strokes, and suicide from loss of jobs, of community and family ties, of homes, and of familiar surroundings.”
in the pdf file linked here:
@ gmax, just saying that “publication” is from the nuclear energy solution, looks like a vested interest to me.
“Why does conventional wisdom ignore hormesis?
For the same reason conventional wisdom ignores homeopathy.They’re both pseudo-science.”
That’s all you got, Bob, argument from analogy, especially a false one. If you think that hormesis has anything to do with homeopathy, then it’s clear that you are not living in the same reality as the rest of us.
The references have plenty of facts that you should try to absorb. Indeed, they have just the right amount; not too many, not too few, you know, just like a “fact-hormetic” effect. 🙂
The issue of homeopathy has been raised. It is interesting to note that, as with many ideas in science, it has followed a tortuous path. It was first rejected by mainstream science after Hahnemann developed the theory in the early 1800s, largely because he calls for a long series of dilutions of the offending agent that reduce the probability that even a single molecule of it remains in the solution. This relegated it to the realm of magic rather than science, even though there are still people 200 years later who practice and consume homeopathy.
But more recently a strange discovery has breathed new life into homeopathy, just as new life has been breathed into Lamarckism (the long rejected theory of the inheritance of acquired characteristics made famous by Kipling’s “Just-So Stories”) through the discovery of the inheritance of epigenetic, in addition to genetic, changes. The homeopathy-related discovery is that nanoparticles, that may constitute the active ingredient, do not participate in the dilution because they stick to the glass of the test tubes in which the multiple dilutions are carried out. They themselves are not diluted and this could explain any seeming effect of homeopathic applications.
Here’s a (peer-reviewed) article by Mark Mattson, written in 2007-8, called “hormesis defined.”
Here’s the google page where we can see that it’s been cited 270 times.
Hormesis is not even particularly controversial. But anti nuclear activists have to treat it as the equivalent of creationism.
On the relation between hormesis and homeopathy (that to conflate them is ignorant), the following is useful:
On the other hand, homeopathy may be making a comeback courtesy of nanotechnology.
You can google it.
Because hormetic dose response curves (typically described as “equivocal” in the peer reviewed literature) remain to be demonstrated at population or ecological level.
Because hormesis (as you describe) is not a concept that is currently questioned or challenged by the scientific community. Careful researchers in this area warn against overly broad generalization from limited and lab based studies, particularly with respect to a “beneficial” or “healthy” adaptive response to stress.
Thanks for the comments. Maybe we can get E. Calabrese to respond.
I would be surprised if Ed thought that the Caspiri/Stern study “settled the matter.” The real point is that Muller settled the matter as LNT became the default position.
Interesting point about whether “benefit” should be built into definition of hormesis. The review article I refer to does in fact treat “benefit” as built into h’s definition at least in the shorthand. so it’s good to have this possible qualification. Most of the studies we have looked at do focus on benefit, not just nonlinearity.
Except for the negative radon/lung cancer relationship derived from geographic data. And the negative relationship of cancers to radiation workers post-1934. And I’m sure more than a few other things I don’t know about yet.
The evidence for a result that is not statistically significant in some epidemiological studies of very low doses is NOT the same as a response that is hormetic. And others do show a statistically significant result that comparable to that of Japanese A-bomb survivors (Muirhead 2009). So you are incorrect.
Cohen’s work suffers from a number of methodological issues (among them the low reliability of the result and the basic understanding that case control studies are more reliable than approaches prone to ecological bias and fallacy). Subsequent studies do show “A significant positive linear trend … between categories of radon concentrations and lung cancer mortality” (here).
Your studies (which are very few in number) are either irrelevant to the question of hormesis, or are contradicted by subsequent research.
EL: this is cohen’s long essay justifying his procedures and addressing the ecological fallacy arguments. He is well aware of them.
In rereading some of this article, I came to realize that Bill and I should perhaps not have used Cohen’s graph as evidence of a dose-response relationship. Cohen actually explicitly warns us against doing what I think we did!!
The point of his article is to test LNT and his figures, including the one we used,
“should not be interpreted to be a dose-response relationship between radon exposure and lung cancer. As explained above, to do so would be falling into the trap of ‘the ecological fallacy’.”
These data are used to test the validity of the linear-no threshold theory (hereafter, LNT) in the low dose region. This test is very different from other tests of LNT utilizing case-control studies (Lubin and Boice 1997), which are really designed to determine a risk vs dose relationship for individual persons. That obviously requires data on individuals, whereas we have only average data on groups of individuals, the populations of counties. Such data on groups are called “ecological data”.
As an example of the difficulty this represents, consider a situation where the risk has a sharp threshold at 50 units of dose. The average risk in the county then depends on the fraction of the population exposed to more than 50 units, which is not necessarily related to the average dose which might be about 5 units. Clearly, the average dose does not determine the average risk, and is therefore not useful for determining the risk vs dose relationship. To assume otherwise is called “the ecological fallacy”. However it is readily demonstrated mathematically that this particular problem does not arise if the risk is linearly related to the dose. In that special case, the average dose does determine the average risk. This is familiar to Health Physicists from the widely used paradigm from LNT that person-sieverts (man-rem) determines the number of deaths; person-sieverts divided by population is the average dose, and number of deaths divided by population is the average risk.
The procedure for testing LNT involves two basic steps. The first step is, assuming LNT to be valid, to transform the risk vs dose relationship for individuals mathematically into a relationship between ecological variables, and the second step is to test that relationship against observation. The first step starts with the BEIR-IV formula (NAS 1988) for risk to an individual, based on LNT, and develops it mathematically, summing over all persons in the county. This and subsequent analyses were done separately for males and females, always leading to similar results, but for brevity here, we confine our attention (with a single exception) to males. The result of the mathematical development (Cohen 1995) for males (with m in units of deaths per year/100,000 population, and r in units of 37 Bq/m3 [pCi/L) is
where S is the fraction of adult males that smoke cigarettes, A is close to 1.0, B = +7.3 (in percent increase per 37 Bq/m3 [per pCi/L], and M is defined by the equation on the left and may be thought of as lung cancer rate corrected for smoking. The data thus corrected for smoking are shown in Fig. 1b.
Eqn.(1) is a relationship between ecological variables—m, r, and S—and hence it accomplishes our first step. Since it is derived mathematically from the LNT relationship between variables for individuals, if the latter is valid, Eqn.(1) must be valid and can be used as a test for the validity of LNT. This use of a mathematically derived formula to verify the theory from which it is derived is a time honored procedure in science. Newton’s famous theory relating force acting on an object, its mass, and its acceleration, F = m a, was not directly tested for centuries since acceleration could not be directly measured; it was rather used to mathematically derive the distance traveled by the object vs time, which was measured to test the theory.
The fact that Eqn.(1), a relationship between ecological variables— m, r, and S—is being used to test LNT represents a radical departure from previous tests. This has far reaching consequences. The principal previous tests have used case-control studies for individuals, which require extensive information on these individuals. But in our approach, no such information is required unless it can be shown that it might affect the relationship between m, r, and S. The difference this makes will be illustrated through the rest of this paper.
It is apparent from Fig. 1b that there is a huge discrepancy between the LNT prediction, B = +7.3, and the fit of Eqn.(1) to the observed data which gives B = −7.3±0.56, a discrepancy of 26 standard deviations. We refer to this as “our discrepancy”. The Scientific Method requires that, if a theory makes predictions that are discrepant with observations and if no plausible explanation can be found for that discrepancy, the theory is invalid. If LNT is to survive the test, we must therefore find a plausible explanation for our discrepancy. The principal purpose of this paper is to describe the search for such an explanation.
Before proceeding, it is important to understand that Fig. 1 should not be interpreted to be a dose-response relationship between radon exposure and lung cancer. As explained above, to do so would be falling into the trap of “the ecological fallacy”. There are only two logical alternatives to consider: (1) LNT is valid in which case a plausible explanation must be found for our discrepancy, or (2) LNT is not valid, in which case we cannot use these data to determine a dose-response relationship.
Perhaps one reason why LNT is popular is because it is so simple. If it is correct then all you need is sixth grade arithmetic in order to figure out the relative risk of exposure to different sources of radiation. But the real world is not like that. Some tissues are much more sensitive to radiation than others. What is needed is sustained research into the effects (both beneficial and harmful) of radiation. Unfortunately support for such research tends to get cancelled if the results of the research are not politically correct.
I’d like to add that the extraordinary fear of (man-made, ionising) radiation among the public is contrasted with remarkable indifference about the danger of fossil fuel pollution. Particulate air pollution in many developed countries is so great that it is causing serious illness.
Almost everyone I ask about their opinion of air pollution (due to the burning of fossil fuels) is ok with it. Even when I mention to my peers (young parents) that this air pollution has a proven negative effect on childhood development according to the world health organisation, it is shrugged off as unimportant. Fossil fuel air pollution is actually said to be something that ‘just has to be accepted’.
The double-standard applied by the public to the externalities of fossil fuels on the one hand and nuclear power on the other is extreme.
If public concern about the risk of ionizing radiation and fossil fuel pollution where proportional to the documented risk of each of these, then the public would be demanding the closure of fossil fuel burning facilities.
If additionally the public understood the cost of (high penetrations of) renewable energy, the threat of climate change, and the predicament of finite fossil fuels, then they would be demanding nuclear renaissance rather than nuclear witchhunting.
Joris – I think your observation is a demonstration of the power of propaganda (a.k.a. Public Relations) coupled with human nature. People are familiar with combustion, yet unfamiliar with things nuclear. The unknown is intrinsically scary, the familiar much less so even if the scientific evidence says that mysterious and unfamiliar thing is a lot safer. The very best propaganda exploits these features of the human mind, which is driven more by emotion than logic.
There is, and has been, a propaganda campaign against anything nuclear from many “environmental” groups who engage in fear-mongering over the tiniest amount of low-level radiation and conflate civilian power generation with nuclear weapons. Do this year after year after year, with support of punitive anti-nuclear regulations from EPA and NRC, and – voila – you have millions of people believing the opposite of the truth and the reign of fossil fuels continues unabated.
I read through the comments (above) with growing incredulity. Hormesis is an intrinsic part of how living organisms survive, how can anyone not understand that?
Polio, measles, etc., vacinations use this effect, the benefits of traces of heavy metals (essential in our diet) are another example… (there were several examples given in the article, but I didn’t find these two) it is so common-place in life!
My personal health experience (obtained by increasing my own ‘natural background radiation levels using some slightly radioactive rocks and uranium glass beads) shows me it works – I have basically said ‘goodbye’ to the so-called common cold since I began my own ‘radiation R’ treatments, two and a half years ago. I only wish (now) that I had started earlier.
“rates as low as 0.01 r/minute”
WHOA! That’s amazing. Kind of like saying, “I got sick from eating aspirin, even at rates as low as 0.01 kg per hour”.
This is 14 mSv/day, 7 times higher than the worst hot spots in Fukushima!
That is good news. It means that the worst affected areas near Fukushima are 7 times below the minimum radiation damage threshold levels as determined by a Nobel Prize winner.
It’s also important to understand that the threshold at which mutation rates for irradiated fruit flies diverged from those in the control group was measured with a difference in rates of just 0.1-0.2%. That might be statistically significant, but is it significant in any other sense of the word? Would it matter to you if your chance of contracting cancer, for example, increased from 30% to 30.1%?
At the threshold, the linear relationship between dose and mutation rates starts at zero and only rises slowly as dose increases. It is not a sharp cliff of safe and dangerous.
Bottom line – radiation is a source of mutation or cancer initiation, but it is a rather weak one.
That would be pretty significant and pretty bad. I wouldn’t want to live in a 14 mSv/day field. This is a 5 Sv/year field. Far more than the 0.1 to 0.7 Sv/year you mentioned elsewhere, which is in the range of hormetic effects. 14 mSv/day is so far above hormetic that it would be most unwise to live in such an area.
If you are going to say we are going to increase your cancer risk by 0.1%, that is not a very good sales pitch. 0.1% adds up to a lot in 7 billion people. If you say it will be reduced because of hormetic effects, much better sales pitch. We should be working to reduce cancer risk.
More importantly 14 mSv/day isn’t relevant to nuclear energy risks. Like I said, the worst affected areas in Fukushima are at 2 mSv/day. This is on the upper end of what is still hormetic so is acceptable. It is a good practical limit. There is no need for a higher limit because this risk is outside of nuclear power operations, especially modern nuclear plants, even with their worst case meltdowns, are well below 2 mSv/day surrounding dose.
You misunderstand my comment. It is not part of my “sales pitch.” Also, your comment about adding up to a big impact over 7 billion people still adheres to the fallacy that collective dose or collective risk is important, even if no individual or family experiences a risk increase that is noticeable among all other risks we willingly accept – like eating a bit too much fatty food, spending some pleasant afternoons soaking up rays at the beach, or waiting for a bus on a busy city street.
I’m not suggesting that we should spend our days in a 14 mSv field, but if there was valuable research to be done there, or an otherwise beautiful environment, or valuable materials to extract and take to market, I would accept the additional risk in order to obtain the benefit. (Astronauts will have to accept substantial doses to journey to Mars, but I would bet NASA would have no problem finding volunteers.)
Dose on mars is much smaller than 14 msv/day. In fact interplanetary space radiation is mostly below 3 msv/day. If risk is real like a real .1 percent increase in cancer, then it is good to extrapolate to get societal effect. Lnt low dose rate is not real, so we should not extrapolate. Traffic accidents kill 2 million a year even though individual risk is below .1 percent for example. You are saying therefore traffic risk is not significant. Thats silly. Also consider non lethality risk. 14 msv per day will almost certainly cause eye cataract. Wont kill you but its not nice at all
I ignore traffic risk every day. So do hundreds of millions of Americans who do not let the statistics prevent them from hopping into car for transportation, even to the most trivial of errands.
Sure, worry warts fret about traffic risk, but most of us don’t give it a second thought. Most of us, however, generally take a few precautions like obeying traffic laws, wearing seat belts and picking cars that meet legal safety requirements.
Perhaps i wasnt clear enough. My point is 14 msv per day is not in any way a low dose rate. So that should not be used as a low dose rate argument like the nobel prize winner used it.
Just because people ignore traffic risk doesnt make it small. That is taking the argument too far the other way. It only proves people dont understand risk. If nuclear reactors were operated like cars we’d have 5 meldowns a day.
The difference between what cohen found and what he expected was on the order of 20-25 standard deviations. You don’t need to magnify this with a clever graph. it’s not about “making the argument look better.” This is not a position that can be quickly dismissed.
drawing the straight line is a convention, an artifact of the commitment to straight line curve fitting. this convention is the default convention of those who assume LNT, which is what cohen was assuming. He found a negative straight line within the interval of radiation he was studying. I would not worry myself about 3 or 6 pCi/L.
My prediction is that raising the regulatory limits will not result in increased public exposure. The goal is not to create design short cuts or modest savings by slightly reducing the amount of material used in shielding. The goal of this exercise in spreading science is to reduce fear and to dispel — as much as possible, since some will never be convinced because they are already members of the anti-nuclear chorus — the idea that all radiation doses are dangerous.
Once people realize that exposure is not the problem, over exposure is the problem, we will have the kind of nuclear technology growth that we need in order to slow the annual addition of CO2 into the atmosphere while dramatically increasing our access to, and use of energy.
BTW – I have already proven that I am perfectly willing to live inside a sealed submarine with a nuclear reactor less than 200 feet from me at all times. I’d love to have an Adams Engine in my basement or backyard. I’d certainly volunteer to accept an annual dose rate of between 100 and 700 mSv.
Note: Atomic Insights has a recently instituted policy of only using SI units with regard to radiation doses, contamination, and activity. There are plenty of conversion tables available.
Say, Rod & company, I’d love to see folks pick apart my calculations in this piece to make sure I got everything right:
The target of the takedown removes any and all critiques, including pingbacks. This is just what you’d expect of an astroturfer, isn’t it?
Let me rephrase. Rod Adams has a policy of using SI units. Sometimes guest posters and graphics created by others (especially if they are older graphics) may use uniquely American units.
I described where the cost savings will happen. The savings are not as a result of changing the radiation dose limits to the public; they will not receive any measurably different doses. The limitations on specific isotopes could be multiplied by several factors, perhaps even a few orders of magnitude, before the dose to any member of the public will be increased by any significant number.
“So, the Radiation Exposure Compensation Act program to compensate “downwinders” and others was completely unnecessary and unjustified?”
what was the dose? The answer to your question depends upon the dose. But of course with LNT, it need not depend upon dose. so even if downwinders got less radiation than the difference between New Orleans and Denver, they should be compensated?
Now: it might make sense to compensate people for the trauma they went thru, but that’s a difficult situation since the experience of trauma itself is connected to irrational fear of low level radiation.
The people who set dose limits and were responsible for public health protection were not the same as those who performed experiments involving injections into unsuspecting people. You are waving a large tar brush at the whole AEC, even though there were thousands of individuals employed by the organization.
The settlements for “downwinders” were politically determined to be appropriate. They were not a settlement for any real health effect as determined by qualified researchers.
‘You symbolically equate open-air bomb tests with radon in homes, and minimize the effects of uranium, plutonium, and fission products in a general way, as though it was equivalent to radon.”
I don’t see how I did this: this symbolic equation. I just made a point about dose.
the dose accounts for all the differences in the isotopes: whatever the half life, whatever the energy, whether alpha, beta, gamma or neutron.
I’m against secret radiation experiments. It’s weird that I have to say this, but guilt by association is pretty powerful.
EL: I’d take a good ecological study (which starts with the environmental differences–here radiation levels–and looks at the health differences in that light), with controls for confounders and very large samples, over a case control study that usually has much smaller samples and starts with the health effect first (cancer or no cancer) and then looks for correlations with the suspected culprit. Cohen has offered very detailed defenses of his study in response to the usual rebuttals about ecological studies. It would be interesting to look at situations where you had well done ecological studies and well done case control studies in the same regions, where the results contradicted one another. Bill S. has some interesting things to say on case-control studies. cohort studies would be best but are most expensive.
Many epidemiological studies are on conventional statistical grounds inconclusive as the confidence intervals include “no effect.” I like the large Cameron study comparing irradiated nuclear workers to non irradiated nuclear workers because it controls for the so called healthy worker effect. If I recall, all the workers are healthier on all cause mortality and most cancer indices, but the irradiated workers (all in low dose regions) have less cancer and less mortality than their counterparts.
tried to post on this earlier. don’t know whether it came thru. This is cohen’s response to the charge he committed the ecological fallacy. what is evident is that Bill and I may have committed the EF by misusing Cohen’s data to tell us something about a dose response relationship.
Here is an article dated today that tells parents to be cautious about using modern imaging technology because of the potential hazard of radiation exposure.
It is phrased as being advocating sensible precautions, but the wording can be taken as a strong warning to parents to be “better safe than sorry,” even with doses that have not possibility of causing any harm.
I came away from the article with a completely different take on it. It just seemed like common sense advise to me, particularly to a parent that may have been subjected to FUD, and has the resultant trepidation and concerns. In fact, it seems to me that a parent with what you consider “irrational” or unfounded fear would have those fears somewhat eased by this article. Perhaps you are setting your sights and expectations too high as far as your efforts to control or banish the public’s fear of radiation. As I’m sure you’ve experienced with your own offspring and grandchildren, erring on the side of caution seems to come naturally. I in no way felt that the article was recommending that parents forego subjecting their child to diagnostic imaging. Quite the contrary, actually.
I’ll admit to something that might have me tossed out of the “good parent” or “good grandparent” club. I’m not an especially cautious person around children. I toss them, push them really fast on old fashioned merry go-rounds, throw them in swimming pools (often to joyous laughter), let them play on the floor of a moving van once we were on an interstate highway, and run with them down hills fast enough to fall giggling on soft grass. My idea of proper child rearing doesn’t include raising wimps. (BTW, my wife and I have two daughters, two granddaughters and one grandson – so far.)
The part of the article that I thought was aimed at causing overly protective parents to err on the side of excess caution (irrational fear) was this paragraph:
If my children or grandchildren have a condition that a physician thinks requires an image, I will ask the technician to make sure she is using a setting that will provide the clearest possible picture, not the lowest possible radiation dose. I will ask for the best available technology, not a non-radiation emitting alternative like ultrasound that produces fuzzier images.
Three years ago, driving a Ford van…..
Through no fault of my own I was involved in an accident that would have killed any children that were not securely seat belted.
Not judging….just saying.
If you review my comment more carefully, you will see that the only phrase in the past tense is the one about playing on the floor of a van when we “were” on an interstate highway. My children, are quite dedicated to the proper use of approved car seats at all times, and I respect their wishes for my grandchildren.
PS – I did not edit the comment after your comment. 😉 One more thing – I am a little surprised that you have not apologized to Greg for your accusation as a result of my error.
I think I have apologized enough here, in the past, for you to realize that I do so when I think an apology is due.
If you read my exchange with Greg, you will note that I clearly informed him that the quote contained in my original criticism was simply copied and pasted from the article. Yet Greg persisted in his claim that the article originally was worded as the edited version. Had someone of told me that an essay, offered by me, had been edited, I certainly would investigate the claim. But really, had I of written a short article such as the topic of this discussion, I would have recognized easily, upon a reread, that it had been edited, and I would have investigated by whom, and why. (Rather than insisting I had said something that I had not). In effect, Greg was calling me a liar, without actually making the direct accusation.
I suffer no ill will towards Greg or you for this misunderstanding, and I appreciate both of your apologies. I hope this closes the matter.
So your response to an implied accusation is to make a direct accusation – several times? Quite mature. Remember, I changed one word and added one word, certainly not a very noticeable change, even to a co-author of the original piece.
Don’t forget tossing them into the air and catching them, until they’re too big for your back to take the strain… 🙂
The tossing game is a sure way to turn a sad face into a giggling cherub. Baby laughter is great medicine for a sore back.
“Scientists responsible for public health protection computed that there was no risk to the public from such small exposures”
Aren’t we talking about the same “regulators” that we are constantly being told are untrustworthy due to an anti-nuclear bias??
You could be forgiven for that confusion, but the key to understanding here is a temporal understanding. The era of open air weapons testing ended completely in 1963, more than ten years before the AEC was split into two organizations, one, the Nuclear Regulatory Commission that was supposed to focus strictly on regulation with a bias toward the notion that the safest nuclear plant was one that was not operating.
The other part of the AEC was set adrift for several years as an organization called the Energy Research and Development Agency and later was folded into the Department of Energy, which has spent the past 30 years researching all types of energy without ever producing any innovation that threatened the established fossil fuel industry again. The most successful DOE energy production program has been providing long term support for George P. Mitchell’s efforts to wrest natural gas from tight gas formations.
Here is the URL of Muller Nobel speech:
This article provides a biological basis to refute the LNT hypothesis and to support a threshold level for negative effects of radiation.
Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), through a combination of time-lapse live imaging and mathematical modeling of a special line of human breast cells, have found evidence to suggest that for low dose levels of ionizing radiation, cancer risks may not be directly proportional to dose. This contradicts the standard model for predicting biological damage from ionizing radiation – the linear-no-threshold hypothesis or LNT – which holds that risk is directly proportional to dose at all levels of irradiation.
“Our data show that at lower doses of ionizing radiation, DNA repair mechanisms work much better than at higher doses,” says Mina Bissell, a world-renowned breast cancer researcher with Berkeley Lab’s Life Sciences Division. “This non-linear DNA damage response casts doubt on the general assumption that any amount of ionizing radiation is harmful and additive.”
“Humans evolved in an environment with very low levels of ionizing radiation, which makes it unlikely that a cell would suffer more than one double strand break at any given time,” he says. “A DNA repair center would seem to be an optimal way to deal with such sparse damage. It is like taking a broken car to a garage where all the equipment for repairs is available rather than to a random location with limited resources.”
However, when cells are exposed to ionizing radiation doses large enough to cause multiple double strand breaks at once, DNA repair centers become overwhelmed and the number of incorrect rejoinings of double strand breaks increases.
The Lawrence Berkeley National Laboratory work that you cite from 2011 was fascinating and certainly showed a great deal of promise. Unfortunately, that work was part of the DOE’s Low Dose Radiation Research program. For unknown reasons, that program was systematically defunded and shut down.
The press release that you linked to was one of the last reports that made it out before the funding dried up.
I wrote a follow-up to the initial article about the disappearance of the Low Dose Radiation Research Program.
To all those true believers of Hormesis, I ask you this
Please detail your regimen by which you obtain additional radiation to increase your health.
I have asked this 60 times and never got an answer, thanks.
and this http://www.ncbi.nlm.nih.gov/pubmed/22458256 ?
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