Biologist explains why LNT is just plain wrong
Dr. Ron Mitchel is a Canadian scientist with a PhD in biochemistry who has been studying the biological effects of low dose radiation on living creatures for the past 35 years. In January 2013, he gave a talk to the Pittsburgh chapter of the American Nuclear Society on biological responses to low dose radiation. Dr. Rita Bowser introduced him to the audience. Though the production quality of this video is not the greatest, the audio is good and the video is clear enough for effective information transmittal.
I’m not sure how I missed this or why it has been watched by only one person per day in the 11 months it has been posted. It is FAR more important for people to spend the next 50 minutes watching this informative presentation instead of watching another episode of Survivor, one quarter of a college football bowl game, or an NCIS rerun.
Here are some highlights of the presentation, in case you are still wondering if it is worth your time to watch.
During her introduction, Dr. Bowser told an interesting tale about her time working with the Mescalero Apache Indian tribe at a place called Inn of the Mountain Gods. That is in the foothills of the mountains near Alamogordo, NM. It is near the Trinity site where the first atomic bomb was tested without telling the Indians in advance of the test. Several of the elders of the tribe described to Dr. Bowser their memories of the day when they saw the incredibly bright light and heard the thunderous roar. It was a searing memory.
While Dr. Bowser lived and worked on the reservation, she taught the Mescalero Apaches about radiation and nuclear energy so that they could take advantage of some of the career opportunities offered by the local nuclear industry. As part of that training, she gave them some demonstrations in which she showed Geiger counter responses to naturally occurring radiation sources.
One of the more interesting objects she measured was the large turquoise belt buckle that the chief always wore. She described how it eased concerns when the chief told everyone that he was not worried, even though the Geiger counter showed a considerable count rate from his constantly-worn belt buckle.
Dr. Bowser ended the introduction by describing how the tribal language had no direct translation for radiation, so the Mescalero Apaches came up with the following phrase in their native tongue – “hot rocks that shoot ghost bullets.” She then asked Dr. Mitchel to describe how his research has answered the question, “Are the ghost bullets harmful, helpful, or do they simply pass right through us?”
Dr. Mitchel told the audience that radiation exposure is one of many possible changes in an organism’s environment that creates a stress. The basic rule in biology in a changing environment is “Adapt or Die.”
Aside: That phrase reminded me of the phrase my colleagues who were Marines often repeated, “That which does not kill you, makes you stronger.” I have always admired the resilience of my Marine Corps colleagues. End Aside.
At about minute 17 in the video, Dr. Mitchel talks to a slide that describes “adaptive response.” That is a characteristic where exposure of cells or organisms to radiation at a low dose and low dose rate (or to any other mild stress) induces mechanisms that protect against the detrimental effects of other events or agents, including radiation.
He then provides about a half an hour’s worth of specific, experimental examples in which adaptive responses have been measured in a variety of organisms. He points out how the effects differ depending on the presence and the magnitude of other induces stressors.
Somewhere around minute 42, he starts to explain why he has serious disagreements with the assumptions and methods used by epidemiologists that have made assumptions about the health effects of low dose radiation based upon their assumed “gold standard” population of atomic bomb survivors. He reminded the audience how the effects his experiments have measured were dependent on controlling for the additional stressors in the environment.
He asked “Is A-bomb survivor data the gold standard for radiation response?” In answer to his own question he said, “I cannot think of a population that is more stressed. They had an A-bomb dropped on their heads.” His slide included the following bullet points.
- Exposed to radiation
- Exposed to physical trauma from the blast
- Exposed to burns from blast
- No food; nutritional stress
- No housing or blankets; thermal stress
He left out a few other stressors that must have affected the population, notably the fact that they were most likely subject to depression from having just lost a lengthy war, and the fact that they were labeled “hibakusha” and ostracized as a result of their classification as atomic bomb victims.
Dr. Mitchel concluded with a slide titled “Implications for radiation protection.” While talking to that slide he emphasized that at low doses, from a biological point of view, all of the basic LNT assumptions are WRONG. (Emphasis in the original.)
The LNT assumes that dose is a surrogate for risk and that every increase in dose results in an increase in risk. As his experimental data show, some doses actually reduce risk, especially in the case where a low dose is given before a substantially higher dose.
The LNT assumes that doses are additive, but that is again belied by the fact that there is strong evidence of prophylactic doses that stimulate defenses against later doses. He pointed out that tissue weighting factors cannot be determined independent of dose and that radiation weighting factors that convert deposited energy (Grays) into risk (Sieverts) have no meaning at low dose.
He recommends a new approach to radiation protection at low dose. In response to a question from the audience, he made a statement that seemed to cause quite a bit of consternation in the audience because it so strongly contradicted all previous training and indoctrination. According to Dr. Mitchel’s research, anything below about 1 mGy/minute is a low dose.
People with a moderate facility with arithmetic can readily compute that 1 mGy/min of Co-60 gamma radiation results in an accumulated dose of 60 mSv/hour (6 rem/hr). By current radiation protection standards, a radiation worker would exceed his annual limit of 20 mSv (2 rem) in just 20 minutes at that rate.
As Dr. Mitchel’s work and presentation demonstrates, our current radiation protection limits are not even within orders of magnitude of limits that would be determined based on actual biological risk determination.
Biologist explains why LNT is just plain wrong
Rod Adams · January 5, 2014 ·’
I’m not sure how I missed this or why it has been watched by only one person per day in the 11 months it has been posted. It is FAR more important for people to spend the next 50 minutes watching this informative presentation instead of watching another episode of Survivor, one quarter of a college football bowl game, or an NCIS rerun.
Rod you HAVE to invite owners of nuclear plants and nuclear labs and nuclear plant manufacturers on your show to explain why none of them has even done a short commercial about that to help themeslves! People don’t get facts by osmosis. only B.S.!
When I organized and hosted the event at which this video was taken, we sent out invites to all the major news organizations around the area. Nobody showed up. So it was just a group of maybe 35-40 people like myself. Other highlights of the session (unfortunately not taped) were:
Dr. Sylvain Costes showing video of cells adaptively responding in real time. We could actually watch the DNA repair happening.
Cal Abel (a contributor here) speaking about his idea for a new dose standard.
Dr. Ted Rockwell calling in only months before his passing and telling us stories about how silly this all is to him.
I also gave a presentation, but I wouldn’t go as far as to call it a highlight. It illustrated the risks and non-conservatisms associated with using a “conservative” model like LNT.
@Cory Stansbury
I wish that more of the event had been taped, but I am glad I found this piece of it, sort of by accident. Thank you for organizing the event, but why didn’t you tell me about it sooner? (Perhaps you did and my aging brain forgot.)
I was also impressed by the fact that Dr. Bowser provided the introduction. I recently heard her speak at the SMR event that I attended in Idaho. She is an excellent speaker and a rising star at your employer. I hope she is continuing to spread her thoughts in executive circles about how wrong the LNT is for predicting the risk from low radiation doses.
Rod,
If I’m honest, I actually invited you to participate in said event. The fact that I never heard back you I attributed to you then working at mPower and me being very involved in the Westinghouse SMR. That said, I don’t think I ever sent you the video after it was made (and I should have). Did you find this on the LNT discussion forum on LinkedIn by any chance?
Dr. Bowser has a degree in Health Physics, so we thought she’d be a good person to open for us. I think she went into this with an open mind and left rather enlightened.
There are two questions here:
(1) Is the cancer risk at high doses accurately known, and
(2) Is the risk linear at lower doses, where epidemiology is inadequate to directly measure it?
Assume for the moment that (1) is true. If (2) is false, and the marginal increase in cancer risk varies with dose, then it must follow that at some dose the marginal increase in cancer rate is GREATER than predicted by LNT. It might be the case, for example, that at low doses there isn’t induction of enhanced repair mechanisms.
If this were the case, it could be that LNT underestimates the number of cancers that would be caused by small additional doses delivered to large populations.
So, don’t think that “LNT wrong” necessarily implies “radiation is less dangerous than commonly assumed”.
@Paul – Did you watch the video? Have you visited Dr. Mitchel’s web site and seen the information presented? There is no need to speculate about the effects of radiation at lower dose; they are measurably less harmful than what would be predicted by extrapolating the damage at higher doses down to zero dose using the LNT assumption.
Humans have been studying the effects of radiation for about 120 years. It is no longer something that is unknown. Rules should not be based on assumptions, but on the results of experimental knowledge.
Paul, we could theoretically imagine a lot of different things for the low dose effects, concave and convex curves, or bipolar, multi-polar, with varying thresholds.
Don’t forget however that many experiments have already tried to test LNT at low dose, and their results have proven that it’s correct that it’s very difficult to demonstrate anything at those doses. We know for sure there’s no large effect at low dose.
This is expected if the LNT is true and the linear relation means the small added amount of radiation has really a small effect. But if the LNT were false in a way where a small added amount of radiation could have a very disproportionately large effect, then those studies should not have had as much difficulty to show an effect. So, they don’t definitively falsify LNT, but they do falsify sophisticated theories of high non-linearity at very low dose that would result in a worrying marginal increase.
Amongst the non-linear theories there’s the threshold one, as well as hormetic curve.
If from start, we were already very near the threshold, or already around the ideal point of the hormetic curve, a small added amount of radiation could push above the threshold, or in the quickly rising part of the hormetic curve, and have a disproportionate effect.
But all the experiment until now have suggested the threshold or the ideal hormetic point is much higher than the exposure of most of the population, including the fact that high natural background don’t have more cancer, but apparently frequently less, and the high radon area in the US do have less lung cancer (cohen studies, which are disputed on whether this *proves* that radon is protective, on whether radon is the only possible explanation for it or not, but have never been disputed on the fact that those area do have less cancers).
Some information I’ve found suggest it could be the same in France, the Limousin area that is probably the most exposed to radon seem to be one of those with the lowest ration of lung cancer both for men and women. And Misasa in Japan has similar suggestive results as already said below.
In searching the literature for evidence of benefits from low dose radiation I found a large body of data that supports a biphasic dose response model for ionizing radiation. Low to moderate doses (less than 100 mSv) produce a stimulatory response to the immune system resulting in lower incidence of cancer and also infectous diseases. This stimulatory effect of low dose radiation is termed radiation hormesis Briefly, low dose of ionizing radiation works like an immunization shot to create a memory response causing heightened long term immunity with beneficial health effects including a lowering of cancer incidence and increased resistance to infectious diseases. Several mechanisms are involved, including radiation induced DNA repair enzymes and induction of a group of enzymes which breakdown free radicals that cause mutations in DNA structure. Other radiation hormesis mechanisms cause the elimination of cells with damaged DNA. DNA damage is associated with an increased potential for cancer. T lymphocytes seek out and cause lyses of injured cells and apoptosis, where in damaged cells program their own death. A low dose of radiation is like vitamin for the immune system.
Here’s a link to a pdf of almost the same slides by Mitchel.
http://www.ansto.gov.au/cs/groups/corporate/documents/document/mdaw/mda2/~edisp/acs013357.pdf
Hmmm. I have an infra-red sauna for routine detoxification via sweating, into which I’ve installed ultra-violet lights to induce Vitamin D formation in my skin. Double-tasking, as it were. Would it not make sense for people to purposefully expose themselves to low-dose radiation for health purposes? Of course, people do this in old caves, Brazil’s beaches, and so on, based on anecdotal evidence of others who have done so. But, if a unit could be installed in my sauna, based on up-to-date radiation science, I’d go for it. Maybe this is not possible in countries dominated by fossil fuel interests, but perhaps Rosatom or Areva could market something like this, in order to promote some good PR in their (fierce) world competition to sell reactors. And promoting radiation science in the course of appealing to people’s self-interest to lead a healthy life sounds like a winner to me, with the proviso that one would need a favorable national government.
Interestingly enough, radium hot water spas (rajiumu onsen) are common in Japan, though there seems to be very little information in English about them. Example (Japanese):
http://kadoyasan.com/radium-world.html
Note that this spa in Misasa, on the Japan Sea side of western Honshu (Japan’s main island) even boasts that according to 37 years of government health statistics, their local mortality rate due to cancer is only one-half that for all of Japan. Their PR even mentions hormesis and the need to do more investigation on low level radiation effects (in Japanese):
http://spa-misasa.jp/radium/
English info. on Wikipedia:
http://en.wikipedia.org/wiki/Misasa,_Tottori
Sure, these spas are businesses that only make money from attracting visitors, but their open promotion of the health benefits of low dose radiation both before and after the events of 2011 is interesting. Note that there are several in Fukushima Prefecture itself.
Sorry, but that typo be overt!
@EP
With a little help from my poetic friends, I might actually be able to produce worthwhile prose.
Poets produce prose poorly.
Does anyone have connections at NEI?
Years (many) ago I worked with Anthony R. Pietrangelo who then was a “Project Manager” (I believe) on the revisions to 10CFR 50.59, The NEI guidelines for implementation of 10CFR5.59, and before that several other projects. After reading a guest posting on this very same subject, still having his email address, I sent Tony an e-mail providing a synopsis of the article and a link to the article. Never heard back. We had corresponded before. Didn’t know he was VP Nuclear then. So it probably got filtered out by his secretary since it was not a nuclear related e-mail address.
Somehow we must get NEI involved in this. It was through the efforts of NEI that the 50.59 rule was changed, which at least until I retired, had a tremendous positive impact on economical operations at all nuclear facilities. Perhaps nuclear plant workers can start a “grass roots” effort with those they work with at NEI, their plant Radiation Managers, Plant Managers, and even higher to get something done.
This link dates back to 2000. It tells us that the story has been known for some time.
http://www.21stcenturysciencetech.com/articles/nuclear.html
Rod, Thank you for presenting a biologists point of view on the LNT model. We need to get the word out about the relative safety of low and moderate dose radiation. Our position must be based on science. This paper: It’s Time to Tell the Truth About the Health Benefits of Low-Dose Radiation by James Muckerheide gives a background to the role of the LNT in suppressing good science concerning low dose radiation. I posted then link above.
Shouldn’t this research apply to radon in basements as well? I;ve thought that the radon protection industry to be a bit of a scam for some time. This is from one state’s website:
“The only known health effect of radon is an increased risk of lung cancer, and exposure to elevated radon levels does not result in any warning symptoms like headaches, nausea, fatigue, or skin rashes. The only way to know whether you are being exposed to elevated radon levels is to test your home (and other indoor environments).”
This is also on the state’s website.
“There is no “safe” radon level. There is believed to be some risk to be associated with any exposure, and as a general rule, the higher the radon level and the longer the exposure, the greater the risk.”
I don’t have the statistical figures, but I wonder if those of us in granite country have a much higher cancer rate. Our basements are not Fernald.
@Eino
Dr. Bernard Cohen did extensive research on radon.
http://www.phyast.pitt.edu/~blc/
Your instinctive reaction, that there is some amount of “scam” involved in the radon abatement industry, is correct.
This is a very good point to make; dose rate is what we should be limiting, not so much total dose.
A good example I always use is to take 1 glass of wine per day for a year. This is a “dose” of 365 glasses of wine per year. If taken in one evening, this will almost certainly kill you. If taken at a rate of one glass per day, there are no effects on health (in fact there is evidence of 1 glass a day being very beneficial).
It would be silly to say people shouldn’t be allowed to drink 365 glasses of wine a year, since drinking one glass of alcohol a day isn’t a health hazard.
The limite of 1 milligray per minute though seems excessive to me. That’s 525600 milligray, or 525 gray, per year. That is certainly not a recommended dose rate! From my reading of various studies, I wouldn’t want to be exposed to that. It is quite dangerous.
More like 1 milligray per hour, is a reasonable safety standard.
Jerry Cuttler and Bernard Cohen are both supportive of setting the record straight. Jerry Cuttler (conservative recommended estimates say levels below 100 mSv which equals 10 rem are safe)
But on the subject of evacuations from Fukushima Cuttler says
FYI: I have a page on radiation with several links to papers and posts about Radiation and Hormesis with a handy Quick Radiation Reference Guide
There is no need for evacuation in any case. The state of the art NRC analysis shows that even with no evacuation, and an instant station blackout (total loss of cooling systems), not even one person is likely to die even with the LNT assumption.
Evacuation is dangerous business. Traffic accidents and all that. Several hundred people (at least) have died from the Fukushima evacuation, some nearly instantly like those who were in intensive care, but most from the draconian post-evacuation environment and its physchological effects (loss of job, house, etc.). Likely hundreds more will die from alcoholism, stress, and the like.
They should have never evacuated the area around F-D NPP. There is no risk basis for it. It is a sad lesson from Chernobyl that we haven’t learned due to radiophobia: fear and stress kills. It’s similar to terrorism, you can’t give in to it. Then you lose.
What does LNT stand for?
Linear No Threshold (LNT) dose response assumption.