The LNT Hypothesis: Ethical Travesties
An old friend shared this classic speech on a nuclear energy focused email list. I tracked down Margaret Maxey and obtained her permission to reprint it for you. The thoughts expressed are too important to keep hidden in private emails.
Begin guest post.
The LNT Hypothesis: Ethical Travesties
Presenter: Margaret N. Maxey, Ph.D.
Professor, Biomedical Engineering, College of Engineering
The University of Texas at Austin
Event: Wingspread Conference, Racine, WI, August 1997
“When I was a child, I spoke as a child
I understood as a child, I thought as a child.
But when I became a man, I put away childish things.”
Paul to the Corinthians 13:11
Slowly but inexorably, radiation scientists are recognizing that the LNT hypothesis – at one time administratively useful in regulating radiation exposures during the infancy of radiation science — has in its maturity become scientifically illegitimate and ethically indefensible. In his book, Has Radiation Protection Become a Health Hazard? Gunnar Walinder, a Swedish radiobiologist, states unequivocally: “The linear, no-threshold hypothesis is one of the greatest scientific scandals of modern times.” Dr. Walinder’s bold statement is indicative of a significant sea-change among radiation experts in their assessment of the validity of using the LNT hypothesis as a basis for setting standards in radiation protection.
Among prominent experts, Leonard Sagan now observes that the LNT model is based on “politics and social concerns,” not science. Nobel Laureate Rosalyn Yalow writes that, “the literature and media overestimate radiation damage even if the overall effect does not differ from zero.” Sohei Kondo at Osaka, Japan’s Kinki University has conducted research into atomic bomb survivors which shows slight decreases in cancer deaths among those exposed to low doses — suggesting that radiation-induced precancerous cells undergo self-killing or apoptosis which prevents later development of a cancer. An emerging consensus concludes that current regulations for radiation exposure are not only “based on quicksand,” but have become pernicious obstacles to the ethical goal they purport to achieve: public health protection.
Radiation protection standards enacted by regulatory agencies have reflected ethical concerns based on two presuppositions:
- that the linear, zero-threshold hypothesis derives from scientific data in radiobiology that are virtually conclusive; and
- that it is “morally better” for health protection to assume that any radiation exposure, no matter how small, has some harmful effect which can and ought to be prevented.
These presuppositions have been reinforced by a popular unscientific belief that industrial man since World War II has introduced into the biosphere enormous quantities of synthetic toxic substances contaminating an otherwise benign natural world. These include “unnatural” radiation sources as well as huge quantities of “sinister” chemicals having no natural equivalents. Hence, official policy has enshrined a quasi-dogma: it is “morally prudent” to assume that “even the most minute dose, even a single molecule, may trigger a lethal change in a cell that will cause it to multiply malignantly.”
Hypothetical Harm: An entire ethical framework for social criticism has been erected on the scaffolding of beliefs which are at odds with the actual status of scientific evidence. Professional ethics compels us to conclude that, despite a vast array of radiobiological data, there is no conclusive evidence to prove the existence or absence of a threshold. It is ethically dishonest to claim that the LNT hypothesis is an unassailable scientific conclusion, when in fact it is only an inconclusive theory, an extrapolated hypothesis, an ultraconservative exercise of prudence. It ignores the fact that humans could not exist if the LNT hypothesis were applied to and enforced upon personal lifestyle exposures to natural terrestrial and cosmic radiation. Evidence of human exposure to wide variations in natural background radiation ought to compel regulatory standard-setting to be based on “standard deviation from background.”
The absence of evidence of harm from low level exposures is not due to incompetence or lack of attempts to find effects. Lauriston Taylor is unambiguous: “No one has been identifiably injured by radiation while working within the first numerical standards set by the NCRP and then the ICRP in 1934. Let us stop arguing about the people who are being injured by exposure to radiation at the levels far below those where any effects can be found. The fact is, the effects are not found despite over forty years of trying to find them. The theories about people being injured have still not led to the demonstration of injury and, though considered as facts by some, must only be looked upon as figments of the imagination.” The inconclusive scientific status of the LNT hypothesis renders ethical arguments dependent upon it inherently flawed.
Hormesis: Scientific evidence now exists for a hypothesis counter to — yet equally worthy of attention given — the LNT hypothesis. Just as there are net beneficial effects from low levels of exposure to otherwise toxic substances — e.g. copper, selenium, fluoride, nickel — there is also persuasive evidence of net beneficial effects from exposure to low- level radiation. Indeed it may be essential for the continued wellbeing of living organisms which have evolved in relation to wide variations in exposure to natural radiation sources. Both LNT and ALARA guidelines unjustifiably assume that any degree of reduction in radiation exposure will do some good. To the contrary, evidence suggests three possible hormetic outcomes: (1) increased growth and fertility in both plant and animal organisms, (2) increased longevity, and (3) reduction in cancer frequency.
Ethical Travesties: Fear of radiation has proved to be far more detrimental to public health than radiation itself. No actual deaths of U.S. citizens have been attributed to accidental releases of radiation from reactors. But fear of radiation has proved fatal: (1) fear of bearing a “nuclear mutant” led 100,000 European women to choose unnecessary abortions after Chernobyl; (2) thousands of people avoid life-saving medical procedures such as mammograms or radiotherapy because they involve radiation; (3) regulatory roadblocks preventing management of harmless low-level wastes are causing many hospitals to shut down radiomedical treatment centers; (4) thousands of deaths from pathogens infecting seafood, eggs, beef and poultry could be prevented by irradiating food. Moreover billions of dollars have already been spent on trivial radiation risks based on grotesque scenarios about (1) single atoms destined to migrate through miles of desert soil to contaminate a potential water source in some distant future, or (2) measurable radon producing sick buildings which require costly remediation or destruction. Fear endangers human health.
Because the LNT model is deeply entrenched in standard-setting procedures of UNSCEAR, BEIR, ICRP and NCRP (UBIN), their bureaucracies have neither cited, discussed, nor refuted the data and theory contradicting the LNT model. Eventually, politicizing and prostituting scientific principles will erode not only the credibility of scientists, but also public confidence in regulatory institutions. Risk-tradeoff analysis is an ethically necessary replacement for the regulatory vested interests now dominating bureaucratic incentives to “keep the hazard alive” — namely, empire building, legalized plunder, research funding, sales of instruments, and indispensible services to a fearful public. An obsession with hypothetical health effects from but one technology siphons attention away from widespread harms claiming the lives of human beings daily.
End guest post
PS – I am looking forward to spending my weekend with some curious, intelligent and interesting young people in Atlanta. As I have done several times in recent years, I will be attending the American Nuclear Society Student Conference; this year’s event is hosted by the Georgia Tech ANS chapter. I suspect I will post a tweet or two on @atomicrod.
Rod,
Thanks for the re-print. It’s funny, a few minutes before reading this I had posted a reply to someones comment on the HuffPo about this very topic. I could have saved myself a few minutes and just added a link here. I wish I could join you at the ANS student conference, but I’ve got some much needed PhD research to catch up on since I was at the HEART conference a couple of weeks ago. If you run into a Dr. Glenn Sjoden at the conference ask if he’s been Hannitized. Dr. Sjoden had been on Fox news as a nuclear engineering expert about one week after the earthquake and tsunami hit Japan.
While Dr Maxey’s assessment appears quite valid,
it is absurd to try to put it forward at a time of an ongoing nuclear crisis.
The suspicion that this is a self interested piece of propaganda that should be dismissed out of hand will ensure not only that it has zero impact with the public, but even worse will damage any future effort to win it serious consideration.
So we should wait until no one is interested for our valid commentary to have proper impact?
Professor Maxey covers all of the points in this argument, but we also have to consider that changing this is going to be difficult.
Part of the problem is that governments and their bureaucracies have painted themselves into a corner backing LNT. Politically, it is going to be very difficult to back down and relax. If the LNT model is correct, there is no “no observed adverse effect level” (NOAEL) for regulators to observe, thus officials responsible for public health can claim justification in calling for keeping radiation exposure “As Low As Reasonably Achievable,”(ALARA)backing away from this will bring down calls of relaxing regulation to favor commercial interests.
Obviously, I disagree. There is never a bad time to share knowledge. You might have a somewhat valid point if I was Tepco, but I assure you that I am not Tepco and am not trying to distract anyone from a damage claim. I am a nuclear professional who is proud of the technology and the people associated with atomic fission. We do important work that provides far more benefit than it is given credit for at a far lower risk than our competition would like you to believe.
Should we allow the oppositon to set the agenda and choose the field of battle. I think not!
DV8 2XL – yes. Changing minds is hard work. So is learning physics and calculus. No one else is going to do the homework; the task is left to the people who have the passion, knowledge and stomach for a public debate. Obviously, I put myself in that category and hope to pull others into the fight.
It is not so much changing minds that is needed but looking to how the necessary changes can be piloted through the system. Sometimes the process is the hardest part, even when all of the players recognize the need for change. In this case the fact that all jurisdictions could not possibly be convinced to change at once makes being the first one very difficult.
Those influences are considerable. Canada’s standards for tritium releases are higher than those in the States, and are being adjusted downward under pressures that amount to “what do they know about the dangers, that we don’t.” This has nothing to do with science, and is driven by a pure political agenda.
We may change minds, but changing regulation is going to be harder, and the time to start laying the groundwork for that is now.
The quote from 1st Corinthians 13:11 does not apply to this secular concern. 1st Corinthians 13 is the classical love chapter of the Bible just as Hebrews 11 is the classical faith chapter of the Bible. St. Paul was writing to the Church in Corinth because of the idolatry and sexual promiscuity of many of its members, and what he had to say is not relevant to this topic. I appreciate and agree with the views expressed on the flawed LNT hypothesis, and I understand why someone woould sieze on verse 11 in chapter 13 of the first letter to the Church at Corinth. But it is a disservice (and inconsistent) to quote one part of Scripture in this secular context at this blogsite when the entirety of Scripture – including moral teachings on marriage and life – are ignored or even condemned as old fashion or midaevil (did I spell that right?). The Gospel ain’t social justice. It’s repentance and conversion, and that is what St. Paul was exhorting the people in the Church of Corinth to embrace. Again, not relevant to LNT.
It never ceases to amaze me that people quote Bible when it suits their purposes, but when it says hard things about sin, then “that’s all Middle Ages stuff.”
No question of the bona fides of the research.
Nevertheless, promoting this research now simply ties it into this accident. That is not going to help the prospect of it getting a fair appraisal.
The problem is that it is hard enough to change bureaucracy policies even when public opinion is on your side. Doing so when the public is scared and deeply suspicious because of a massive nuclear accident that stems from inadequate design is impossible, imo.
For pity sake, the quote from 1st Corinthians 13:11 is an epigraph not a citation, and it is speaking to maturing of attitude which is quite apropos to this issue.
Of course people quote the Bible when it suits their purpose, (Why else would they?) after all it is in the public domain, and not the intellectual property of self-exploited inquisitors sniffing about for heresy.
There is no better time to have a discussion on this subject then right now. Many people are concerned about the long term effects of Fukushima, much of that concern is unwarranted but there are legitimate issues to discuss.
So just like emergency situations in other industries that result in new or revamped methods, this is the time for the nuclear industry to open the books up so to speak and ask questions that challenge standard ways of thinking and myths. Why? Because real life data will be once again be collected and analyzed by many different types of professionals to add to the Chernobyl data that is still be collated.
When else can we have a discussion on issues of radiation, contamination and their effects on the general public if we don’t have that discussion right now? If these issues are not brought up for discussion now then they never will. The end result will that the anti-nuclear side will be free to continue their campaign of spreading fear and doubt.
The NRC some time ago proposed a reasonable approach to this and got hammered. They had suggested a “below regulatory concern” threshold to be established. Never happened.
So LNT theory is overly conservative.
The nuclear power generation industry has been able to design plants and operating procedures that comply with it.
The final paragraph summarizing the effects of policy based on LNT theory sounds disingenuous to me.
I wish the author would state clearly why the policy should change.
I am guessing the real reason is “Nuclear Power is being held to a higher standard than medical devices and natural sources of radiation. Those higher standards add costs and fuel the public perception that any amount of radiation will cause you harm.”
I would like to hear this person’s comments on the radioactive levels present at the Japan site, specifically in the reactor building. I read that the reactor will need to be isolated for decades but no discussion of that on these blogs.
@etudiant
This is precisely the time to talk about these issues. They are top of mind, on a bubble of Fear, Uncertainty, and Doubt whipped up by poorly informed media and anti-nuclear groups. The FUD needs to be countered with knowledge and science. I would rather know the true magnitude of a risk than be left uninformed with various people fanning fears.
Well, the LNT dose/effect modell is overly conservative especially at the lower end of the scale (low dose + low doserate and medium dose + lowdose rate). Chen at al, hints at the fact with ample sample size (~10,000) with dose rates from 7 mSv to 70 mSv and a significant drop in general cancer cases including leukemia. [Is Chronic Radiation an Effective Prophylaxis Against Cancer?].
This article should be read by any budding radiation “expert”.
The policy should change because use of the LNT may be overstating the effects of small concentrations of radioactivity in the environment that may result from an accident. Planning and expeditures to deal with possible accident scanarios should be based on better information. Also, if people are lead to believe that no matter how small the doses are, someone will die, they may not accept a course of action even if in the end the result is better for them. Choosing coal over nuclear fission is an example one example. Another example, not related to radiation exposure, is some people’s fear of artificial sweetners. I’ve seen people with very large weight problems continue to consume sugary sodas instead of diet drinks becaue they heard that the artificial sweetners cause cancer. They ignore the effects of weight gain and the possibility of developing diseases such as Type II diabetes in order to avoid the remote risk of cancer.
As far as your last paragraph, there have been a lot of comments and discussions about the higher radiation fields around the plant.
Ioannes, you do yourself a disservice. By stereotype, you accuse Dr. Maxey of discarding Biblical references when she finds them at odds with her views. Since Rod is reprinting Dr. Maxey’s remarks with her permission, it would be inappropriate (and potentially hypocritical) for him to selectively veto pieces of it without having acknowledged doing so. The honest thing for him to do is present her remarks as her own, which I believe he has done.
You may disagree with the how the Scripture is cited, and you have. But to accuse Dr. Maxey of inconsistency, you should be able to cite her remarks that support your claim.
As for this being a secular context, there are some rare people who do not segment their lives and wear different faces or beliefs in different settings, but endeavor to carry out their beliefs in all aspects of their lives, whether they frankly name the source(s) of those beliefs, or not. For people who seek to be whole in that aspect, there is no such thing as ‘secular’ contexts.
“It doesn’t matter what you’ve heard. Impossible is not a word. It’s just a reason for someone not to try.” -Kutless
“It’s hard to fight an enemy who has outposts in your head.” -Sally Kempton
“Hard work spotlights the character of people: some turn up their sleeves, some turn up their noses, and some don’t turn up at all.” -Sam Ewig
Shame on those whose only contribution to the discussion is to say it’s hard, it won’t work, it can’t be done, it shouldn’t be tried, now is not the time.
Now is the time for change. For people like Rod, it’s the opportunity for making changes based on real science and peer-reviewed studies, and discard the health-harming options of the old school with the now-false excuse of “we don’t know what the risks are of low radiation exposures.”
Obviously, when the world is paying attention is precisely the time to share knowledge.
But there is a problem here, in that the issue is not as Dr. Maxey describes. Overstating a case can be counterproductive. Dr. Maxey writes:
“It is ethically dishonest to claim that the LNT hypothesis is an unassailable scientific conclusion…”
BEIR does not claim this. They use the word “model” most often, i.e. as in the LNT “model” fits the data as they see it. They also call LNT a “hypothesis”. They call LNT “the most reasonable description…”. They never say they have proof for LNT. They say categorically that “at doses less than 40 times the average yearly background exposure (100mSv), statistical limitations make it difficult to evaluate cancer risk in humans”.
Dr. Maxey states “bureaucracies”, but names BEIR as well, which I take her to mean BEIR “neither cited, discussed, nor refuted the data and theory contradicting the LNT model”.
BEIR panel members are mainly scientists. They discussed many possible ways to explain the data that is contained in the literature. Hormesis, various ways to express LNT, the idea that there is a threshold level below which no harm is caused but which brings no special benefit, and the idea that at very low levels much more harm is caused than LNT suggests are all discussed. Prominent proponents of hormesis are discussed by name. There are more than 1000 papers listed in their references.
If Dr. Maxey means the bureaucracies that enforce radiation standards which have been set up or enacted into law based on someone’s understanding of LNT, these standards that have been imposed on the nuclear industry that make no sense given how much radiation people are exposed to in other areas of their lives, she should say so.
BEIR pointed out in their summary that “the lifetime odds that an individual… will die in a traffic accident are… one in 77”.
When Dr. Maxey writes: “politicizing and prostituting scientific principles will erode not only the credibility of scientists, but also public confidence in regulatory institutions”, because she names BEIR, I would say, given that she apparently is attacking BEIR for what it has not done, she is undermining public confidence in BEIR. Congress set up the National Academies to provide a place where ordinary citizens can go to get independent assessments of scientific issues by recognized experts.
Because the BEIR panel was created under the auspices of the NAS NRC, she is undermining the National Academy. These charges she makes, i.e. that organizations such as the BEIR panel are “regulatory vested interests now dominating bureaucratic incentives to “keep the hazard alive” — namely, empire building, legalized plunder, research funding, sales of instruments, and indispensible services to a fearful public” do not apply to BEIR given the case she makes.
If she believes the scientists who worked on BEIR panels are this corrupt, she should make a better case, or her writing will tend to reinforce all those who believe pro nuclear advocates who say radiation is not as harmful as anti nukes suggest are just as anti science, and anti rational as the anti nukes.
It does little good to point out what is in the latest BEIR reports, since this was written in 1997, before the latest reports were published.
When Dr. Maxey is talking about BEIR, she’s probably referring to BEIR V.
It’s not overly conservative; it’s wrong. Small doses of radiation aren’t harmful; they’re beneficial. Spending ratepayer money to add layers of protection to keep workers and the public from something that is health beneficial was conservative policy when we didn’t know what the effect was. But now where we do know the effects, we we need to tear down the regulatory edifices that keep that former ignorance enshrined, waste money, make nuclear needlessly more expensive and enhance the competitiveness of alternate power sources that are harmful to the environment and to public health.
David Lewis – Nowhere in the practice of science is any body granted the right to speak ex cathedra. This includes the U.S. National Academies. Your constant refrain that their work is above question and above reproach demonstrates a breathtaking naïveté.
The funny thing is that I am sure that the members of the National Academies would be the first to tell you so.
You won’t find anywhere where I say the work of NAS independent expert panels is above question.
No one grants the NAS the right to do anything.
From the NAS website: “The NAS was established by an Act of Congress… …which calls upon the NAS to “investigate, examine, experiment, and report upon any subject of science or art” whenever called upon to do so by any department of the government”. The idea was to provide independent assessments of scientific issues that policy makers were concerned about. “The Academy membership is composed of approximately 2,100 members and 380 foreign associates, of whom nearly 200 have won Nobel Prizes.” That’s almost 10% of the members have Nobels. The members are “elected in recognition of their distinguished and continuing achievements in original research”. Its not easy to get in. “election to the Academy is considered one of the highest honors that can be accorded a scientist or engineer”.
They don’t have the right, but they do have a mandate to set up a panel when a government department asks them to assess something and issue a report. People can throw the reports into the garbage if they want. You have the right to tell people to throw the reports in the garbage. I argue this is not wise. Because of the high quality of the members a lot of people all over the world take what an NAS panel says seriously.
That argument between Monbiot and Caldicott shows how the BEIR VII report in particular proved very useful as Monbiot’s former respect for Caldicott crumbled away when he realized what she was saying is not supported by scientific assessments such as BEIR VII. Monbiot claimed to have read the entire thing. Anyone reading that would have a very good idea about what is known about radiation afterwards.
What I do say is it is clear that there is a dispute among reputable expert scientists studying radiation as to what the effects at very low doses are, and I question nuclear advocates who argue otherwise.
Its fine to say there is this evidence or that evidence for hormesis, or for the idea that there is a threshold below which no harm can be or has been demonstrated. But when nuclear advocates go as far as Dr. Maxey does in this post, to accuse scientists who disagree with her of corruption, or of not considering any other hypothesis other than LNT, they don’t look credible to the non expert who is wondering where the truth lies.
In reply to Brian Mays: I didn’t realize Dr. Maxey was writing so long ago.
A review of the older BEIR assessments shows how things have evolved. BEIR V said “departures from a linear model at low doses, however, could either increase or decrease the risk per unit dose” which granted a degree of credibility to the Sternglas, et.al. idea that far greater harm is caused by extremely low doses than LNT suggests. By the time BEIR VII reported, they could say it was clear that “radiation health effects research, taken as a whole, does not support this”. People can be upset that LNT allows projections of harm from Chernobyl to be calculated as 1 million dead, but a greater harm than LNT hypothesis, if granted the slightest credibility by BEIR would have allowed Greenpeace to claim far more will die.
BEIR V contains a clear statement on natural variation in background radiation: “studies of population chronically exposed to low level radiation, such as those residing in regions of elevated natural background radiation, have not shown consistent or conclusive evidence of an associated increase in the risk of cancer” BEIR V also noted that their estimates of risk were higher than BEIR III. BEIR VII lowered the BEIR V risk estimate as I recall. BEIR V clearly states they have no proof: “The committee recognizes that its riak estimates bcome more uncertain when applied to very low doses.”
But BEIR V supports versions of LNT. Writing about cancer and hereditary defects: “the frequency of such effects increases with low level radiation as a linear, nonthreshold function of the dose”. They considered all other ideas contained in the literature. The panel members were reputable scientists – the members are listed here: http://www.nap.edu/openbook.php?record_id=1224&page=R3
So my critique of Dr. Maxey is about the same.
Quoting from the GAO: “The standards administered by E.P.A. and N.R.C. to protect the public from low-level radiation exposure do not have a conclusive scientific basis, despite decades of research”.
Its a different thing than to say the people who don’t agree with me are criminals.
Kelly – thank you for your support. You’ve figured me out – I am not a passive reporter, but someone with an agenda for change. I need all the help I can get. We really can make a difference if we try.
I’m now heading to an ANS Student Conference public meeting. I hope it is an opportunity to share my passion with people who are genuinely interested in learning more about nuclear energy and radiation health effects.
Applied LNT: airlines are more dangerous than Chernobyl.
The funny part of the BRC story is that when the political crap hit the fan the industry backed away from the NRC at about Mach 5.
Friendly fact check: The LNT model predicts 4000-9000 early deaths from Chernobyl due to radiological-induced cancer, as assessed by the UN report in 2006 (but using the rider “up to” the number given). Several organisations including UNSCEAR have changed that to “no detectable effect”, which better reflects reality. The only way to get to a million deaths is anti-nuclear hysteria of an order that even Greenpeace needed to work themselves up to.