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Nuclear accidents & the scientific consensus feat. Gerry Thomas

Dr. Geraldine Thomas is the director of the Chernobyl tissue bank and a Chair in Molecular Pathology at the Faculty of Medicine of Imperial College London. Surprisingly her research on the health impacts of the Chernbyl accident led her towards a pro-nuclear position due to the technologies clear benefits of slowing climate change and saving lives by producing no air pollution.


Dr. Thomas shares that contrary to popular belief there is a scientific consensus that the Chernobyl accident has resulted in the deaths of less than 55 people as a result of radiation. This is based on the work of the UN scientific committee on the effects of atomic radiation (UNSCEAR) and the Chernobyl Forum that involved 8 major UN agencies and the participation of Russia, Belarus and Ukraine.



Alternative reports quoting death tolls orders of magnitude higher are methodologically flawed and were sponsored by the European Green party and NGO's like Greenpeace who had an ideological objective and cherry picked evidence to match their hypotheses. For more information from Dr. Thomas see below https://www.chernobyltissuebank.com/useful-podcasts-and-videos.htm


Transcript Below:


Chris Keefer [00:00:03] Hello, everybody, and welcome to the Decouple podcast, where we explore the science and technologies that can decouple human wellbeing from its ecological impacts and the politics that can make decoupling possible.


[00:00:21] Welcome back to the Decouple podcast. Today, I'm joined by Dr. Geraldine Thomas, who is a senior academic and Chair in Molecular Pathology at the Faculty of Medicine of Imperial College, London. She's an active researcher in fields of tissue banking and molecular pathology, particularly of thyroid and breast cancer. She's also the director of the Chernobyl Tissue Bank. Dr. Thomas is a science communicator and has written editorials and provided comments to the media following the Fukushima nuclear accident. Dr. Thomas, it's an honour to have you on Decouple.


Geraldine Thomas [00:00:51] Thank you very much.


Chris Keefer [00:00:53] I heard you recently speaking to a forum on Women for Nuclear, and we were able to get in touch after that. And it was a really excellent talk. I wanted to start by asking you some questions about tissue banking, as you are the Director of the Chernobyl Tissue Bank. Can you tell our listeners a bit about that area of work and what kind of questions you've been looking to answer with the specimens that you've collected?


Geraldine Thomas [00:01:14] Well, of course, you know, the best thing to examine if you want to understand human health is a bit of human tissue. And, of course, that comes with all sorts of, you know, ethics and everything else that goes around it. So when we realise the Chernobyl accident had happened--it's an experiment that should never, ever be repeated, if you like. So one of the first things that I really wanted to do was to make sure that we learnt as much as we could from the accident. And one of the major questions that people have was, was thyroid cancer that was induced by radiation somehow different from thyroid cancer that was induced by whatever else induces thyroid cancer. You have to remember that at the time the accident happened, it was the fall of the Soviet Union, so there was complete chaos. There was very little money for medical research. So it is really important to work with the institutes in Ukraine, Belarus and Russia to be able to bring them up to speed for biological research and to preserve stuff for the future, so that everybody who had a good and valid reason and a good idea about understanding the mechanisms as our cancer post-radiation would be able to have access to human samples that were obtained ethically and legally. So that was the basis of the Tissue Bank.


Chris Keefer [00:02:25] I was four years old at the time of the Chernobyl accident and wondering, for your generation, if it was kind of like 9/11 for us in terms of, do you remember the day of, or what you were doing at the time?


Geraldine Thomas [00:02:39] I remember what I was doing when we found out there had been an accident. I was actually watching the BBC News. And as things usually go with the BBC and in the UK, there was a comment about that there had been--I think it was a group of students in Kiev for whatever reason. But of course, they were absolutely fine. And that was that was the one thing that sticks in my mind, because, of course, in the West we only really found out about it about a week later after the accident happened because it triggered a radiation monitor in Sweden. And then we were starting to investigate as to what had gone on in the former Soviet Union and why there was this radiation cloud. So, yeah, that's really all I remember of it. And then, of course, it went fairly quiet for for a while. And then and the early nineties, it was becoming obvious there was an increase in thyroid cancer in those who were children at the time of the accident. And that's when I really got involved.


Chris Keefer [00:03:34] I think, in researching a little bit about you it seems that, like myself, you grew up in a kind of left-of-centre environment. And having experienced that myself as well, you know, there's a kind of implicit anti-nuclear bias that I only sort of discovered when I got into researching this recently. You've actually said that it was your research on Chernobyl that made you become pro-nuclear energy. Can you explain that paradox?


Geraldine Thomas [00:03:58] Yeah. I mean, I think like most people, I conflated, you know, atomic bombs with nuclear energy. And of course, they're two totally separate things. The physics might be similar, but that's about it. And so, I mean, I've been brought up fairly left-wing; I was a left-wing academic, and being anti-nuclear in its broadest terms sort of went with the territory. But, you know, when examining it, it was really nuclear weapons that most people were against. But there was this confusion between nuclear weapons and nuclear power. So it naturally came that if you were anti-nuclear weapons because nuclear power plants produce plutonium, therefore you should also be anti-nuclear power. But when you start working on something like Chernobyl, and actually go well, hang on, why am I so against this? The health effects are not what people would have had us believe. I really need to examine the pros and cons of using nuclear power now, knowing what I know now about the health effects, rather than what I thought I knew before I started working on it. And it was pretty obvious to me that actually there are an awful lot of benefits for nuclear power and that if you put it on the balance system, actually nuclear power comes out as a pretty good way of producing energy, which we're going to need if we want a westernised world.


Chris Keefer [00:05:12] Are you thinking about its benefits in terms of reducing air pollution or do you have any other [reasons to support nuclear]?


Geraldine Thomas [00:05:17] Reducing air pollution, also using a small density of the land to produce a highly dense energy source, so that you're not obliterating mostly the countryside with windmills or with solar panels. But also the fact that it's also a clean--in terms of carbon usage--a clean form of producing energy. So it's got lots of benefits. And if you if you actually look at the health effects, there's been quite a lot of research into this. Nuclear power comes out as the best way of making electricity. You know, when you take into account accidents in hydroelectrics, or from people switching off windmills or solar panels. It really is quite shocking to realise that nuclear is that much better than virtually anything else we can do to produce electricity.


Chris Keefer [00:06:02] Yeah, I've certainly heard that the safety culture at nuclear power plants is something to be admired, and also just a little bit comical in terms of, even things like railings on stairways needing to be kind of overengineered.


Geraldine Thomas [00:06:15] Yeah, everything is overengineered because they're terrified of there being an accident, because they know accidents are going to turn public opinion. And also, you know, you're brought up with your work with radiation, with knowing that it's potentially dangerous. So you have tremendous respect for it. But you can't go a little bit over the top. When you start looking at one risk, and one risk only, you find that you're introducing other risks. And a good example of that was in Fukushima, they were kitted up to the nines to avoid radiation exposure. And somebody forgot to remember that in Japan in the summer, it's incredibly hot. So you had the people working in full PPE to protect them from the radiation, but they were fainting. And in fact, I think somebody actually had a heart attack from overheating when, you know--so you introduce another risk that was actually more dangerous to the person than the radiation risk was. You have to be really careful.


Chris Keefer [00:07:08] So let's circle back to Chernobyl. What have been the major health impacts of the Chernobyl accident?


Geraldine Thomas [00:07:13] Well, the scientific consensus is that the only radiobiological effect has been an increase of thyroid cancer in those who were children at the time of the accident. So under 19, with the youngest exposure carrying the greatest risk, that's it. That's the only thing we can see. People were worried about the amount of caesium that was around in the atmosphere and whether that might cause something. But actually, when you start to understand the difference between physical halflife, a biological halflife, you understand that the dosage that they got from caesium was actually quite small. In fact, most people got the equivalent over 25 years of about one C.T. scan. Iodine was different because iodine is concentrated in the thyroid, and it's particularly dangerous when it's given to young children because the thyroid is still growing. But apart from that, there is nothing to see. There's an awful lot of work going on with those who were working in the clear-up operations, the so-called liquidators. And so far, we've yet to see an increase in either leukaemia or solid cancer that we can say is due to radiation. Which, you know, thirty-five years almost after the accident, this is a little bit surprising. Most people were expecting to see an increase in solid cancers and we just haven't seen it yet. Obviously, it's a bit early. You know, some people say you should wait 70 years, but if there was a really big increase, we'd have started to see something by now.


Chris Keefer [00:08:37] So certainly nothing measurable.


Geraldine Thomas [00:08:39] Nothing measurable at the moment.


Chris Keefer [00:08:40] You know, it's interesting because I think, you know, a lot of our listeners hear you say that and they know about your expertise. But they would question you because I think there's been some, you know, numbers that have been put out there that are vastly different. You talk about the scientific consensus, and this is something, I think, that comes up a lot around issues like climate change where, you know, the people who are climate change deniers will find fringe scientists who have PhDs, and sort of selectively reference their work to make an argument against the reality of climate change. Do you think that there has been a similar pattern in terms of how the Chernobyl accident consequences have been looked at?


Geraldine Thomas [00:09:21] Yes, I mean, certainly some of the stuff that I have read has been very selective. It is easy to ignore the large body of scientific evidence. And, you know, when you read papers, you have to be very careful. You look at the methods, you look at the results, you look at the statistics. And I think we've a tendency--particularly now, less when I was an undergraduate postgraduate--but I think now many more members of the public will take what's written online as gospel and not even think about it. Whereas the first thing I think of was, okay, so what else might have caused that? And it doesn't matter what I see on the news. It'll always be, are you sure it was caused by that? Could it be caused by something else? And there's this so-called alternative hypothesis that I was brought up to--you'd could go into your work with a hypothesis, you'd say, well, the results fit my hypothesis, but hang on. Have I excluded everything else that might give me the same results? We seem to have lost that culture.


[00:10:15] And if you look at a lot of the sort of more popular science around Chernobyl, a lot of it actually ignores things about the changing way in which things are reported. Clinical cancer registries change over time, diagnoses change over time, diagnostic techniques change over time. The whole of society, particularly in the Soviet Union, has changed in terms of health care, reporting, etc. And if you gonna do the science properly, you got to take all of that into account. And unfortunately a lot of the other--you know, the so-called pseudoscientists tend to just take it at face value, which you can't do with human health. It's very complicated.


Chris Keefer [00:10:53] So specific to the Chernobyl accident, when you talk about the scientific consensus, can you tell me which which report you're referring to and what that report looked like, who was involved?


Geraldine Thomas [00:11:03] Yeah, the best reports are probably the UNSCAR reports, the UN Scientific Committee on the Atomic Radiation. And it's usually--Annex D is the health effects one, which is the one [you need]. You can get all online, so it's no problem accessing this information. You'll hear the anti-nuclear saying, well, we're all paid by industry who work on this UNSCAR reports. I can tell you that's just simply not true. If you've ever sat in one of those meetings where we're discussing writing one of these reports, we can argue for a whole day on two or three words to make sure we've got it absolutely right. And there are all sides of the argument within those rooms. You have people who are experts in every single field. So, you know, the biodosimetrists speak a language I barely understand and need somebody to translate for me. We have physicists, we have health practitioners. You have people like me who are interested in the molecular biology. And we will sit there and we will argue through these papers for months. Many of these reports take actual years to produce because of the number of times we'll go back and say, well, is that a valid argument? Have they reported it properly? What about this paper? This paper says something else. So those are the reports that I would say are probably the best, that are justified in terms of the scientific evidence base.


[00:12:19] If you want to read something that's a little less technical (and they are highly technical reports) we did a radiation restatement with the Oxford Martin School who, bless them, having done lots of other controversial areas of science, thought that they would probably take about, you know, maybe three months to produce this. It took three years. There were so many internal arguments with the scientists as to how the evidence should be presented, which were the best papers to include. And they produced it in a way that you can say, well, there's a consensus on this. There's no consensus on this statement. And there's an emerging consensus. So if you want to see the way in which science improves with more and more evidence over time, it's a really good way of looking at the evidence around low dose effects of radiation--how that's been obtained, and where the good evidence is and where the less good evidence is for some of the statements that are made. That's available online. Just Google it.


Chris Keefer [00:13:15] So when talking about some of these alternative reports, because, again, there's vastly different estimates of, you know, the number of people affected or even killed by the terrible accident. There's been other studies that contradict the Chernobyl Forum and the UNSCAR reports. Can you talk a little bit, or have you looked at those reports? Do you have a sense of how methodologically sound they are, and whether they represent large numbers of scientists?


Geraldine Thomas [00:13:40] We have looked at them and they're not methodologically very sound at all. The problem is a lot of it is taken from the Soviet literature where they've been incorrectly controlled studies and you can't tell what was actually causing the increase. It might well have been something else in the environment that changed, [or] the way that things were being reported. It's just extremely difficult to tell, without having a proper control population and a proper controlled study, whether what you're saying is due to the radiation. The famous one that everybody quotes is the Yablokov study that was published by the National Academy of Science in the US, where they just said, you know, there were several--I can't remember the exact figure, but several hundreds of thousands of people had died since Chernobyl. Well, of course they have, because unfortunately, death is a natural occurrence in life. We're all going to die at some point. The surprise is when and how. And the problem is that unless you take into account all the other factors that impinge on health, then you can't necessarily say that all of those deaths were due to radiation. And there's a really good report, a white paper by UNSCAR, that I think came out in 2017, that looks at the uncertainties around exactly how many thyroid cancers were really caused by the radiation, how many were caused by better detection and things like that. And actually, it's really difficult to attribute something to radiation because so many other factors cause the same thing.


Chris Keefer [00:15:10] So can you just briefly give us a sense of what the--according to the scientific consensus, what the numbers are in terms of people who died as a result of the accident, or who got cancer as a result?


Geraldine Thomas [00:15:22] We'll break it down into different categories. So, at the time of the accident, there were three deaths that occurred that were not related to radiation, but related to the accident: so somebody died of a heart attack in the power plant, somebody is still buried under the rubble, and somebody else died of thermal burns--because you have to remember, there a fire as well. So that was thermal burns also occurring in that population. Then you had the people who were the first responders. So you had the firemen who came, who were brought in to put out the fire. And about a 135-140 of those had sufficient radiation to give them acute radiation syndrome, which is when it starts attacking the stem cells in the body. And, you know, it is quite often fatal.


[00:16:08] Now of that 140-ish [acute radiation syndrome cases], 28 actually died within the first weeks and months after the accident of acute radiation syndrome. And these were people who had doses over a sievert. Interestingly, those who died also had thermal burns as well, because obviously thermal burns are also pretty detrimental to your health. So it was interesting it was only those who had thermal burns, who also died. So there was a combination of factors going on there. They actually used G-CSF, which we now use to treat cancer patients to maintain their bone marrow as well while treated with cytotoxics, for the first time in man in that group of people, and that probably helped some of them survive. Now, 19 of that little cohort that have very high doses have subsequently died, but they died of things like car accidents, lung cancer, liver disease or alcoholism. One, I think actually died of a solid cancer, but only one out of the 19 who've died subsequently. So, you know, even though they had high doses, there's not been a stratospherically high proportion of them dying of cancer. Now, you can argue that's because actually they have other things that kill them faster, like they drink too much and smoke too much and drive too fast. But, you know, even in that high-dose sector, we haven't seen untold numbers of cancer.


Chris Keefer [00:17:34] So it seems like radiation is, contrary to popular belief--you know, there is a carcinogenic potential, and as you mentioned, in children who got really high doses of iodine-131, the link is obvious--but in general, radiation, even in high doses, seems to be a pretty weak carcinogen.


Geraldine Thomas [00:17:52] It is a pretty weak carcinogen. Going back to the numbers, we know that we've had 15 fatal thyroid cancers so far. We are expecting an excess of around about 16,000 thyroid cancers up to about 2050, because it is a quite long latency with some of these cancers. The good thing about thyroid cancer is it has a mortality rate of about one percent. So you would reckon that about 160 of that 16,000 may die of their thyroid cancer, but they won't die quickly. That's the other good thing about thyroid cancer. It rarely kills you quickly. The 15 who've died so far were actually--we got to them too late. They all got extensive metastases, and so they've died relatively quickly. But many other people will go on to live normal lives, and live through their lives, and may actually not die that thyroid cancer at all. Ninety-nine percent of them will not die of their thyroid cancer. So that's not a huge number of deaths. It's a large number of cancers, but it is treatable cancer. And you can replace the thyroid when you remove it surgically for treatment with thyroxine.


[00:18:57] Then you've got to consider the liquidator cohorts, so the people who were the first responders, the cleanup people who went through after and cleaned up the plant. And there's about, I think, six hundred thousand of those who were in various cohort studies. And as I said earlier, we haven't yet got any evidence of an increase of any form of cancer or leukaemia in that cohort. But you could argue it may be too early to say definitively there were no cancers in that cohort.


Chris Keefer [00:19:25] And I think the big irony here is that the poison is the cure for for thyroid cancer, is that right?


Geraldine Thomas [00:19:31] Yeah, people find that very difficult to understand that we get very high doses of iodine to kill off thyroid cancer cells. After you remove the thyroid itself to kill off any remaining cancer cells, you give high levels of radio iodine. And it is the magic bullet. It is one of the most effective treatments for cancer that we have because it targets only the thyroid cells. So it has little toxicity as well. But if you keep a low dose and you give it to children--and that is the key point. If you or I as an adult, me as a rather more senior adult than you were to have a dose of iodine, it wouldn't give us cancer. Unfortunately, the child, because its thyroid, is small, it receives a fairly high dose. Also, children also drink more milk, and one of the major routes of exposure was drinking contaminated milk. So lots of reasons why the doses were higher in children. But the key thing is the thyroid is still growing. There's this idea that if you give a mutagen, it doesn't matter what the physiology around when you give that mutagen is, [but] it really does matter. If you give a mutagen like radiation early in life while the organ is still growing to an adult size, you tend to keep the mutation, so you eventually will get cancer. And it's something that people find very difficult to understand. For me, it's a sort of natural thing because I totally get the initiation and progression phase of cancer. It's the growth that produces the progression phases of cancer. But it is odd when when you try to explain to people: if adults have iodine or are exposed to radio iodine, it's not really a worry. But if children are exposed, there's much more of a worry.


Chris Keefer [00:21:17] So just getting back to those alternative reports that are outside of the scientific consensus, I think there's the other report on Chernobyl. There is the Yabokov study you mentioned. It seems like a lot of these reports actually were either sponsored by Green Parties or--?


Geraldine Thomas [00:21:33] Yeah.


Chris Keefer [00:21:33] So the environmental movement, Greenpeace, the Green Parties, they're often, you know, when you look at surveys from the public about their credibility and honesty, they're ranked very highly. Are they looking at the science and sort of an objective way and an openminded way, looking for conclusions, or do you feel like their conclusions already kind of made up?


Geraldine Thomas [00:21:55] Their conclusions fit their original hypotheses, I think is the problem. I have had some very interesting encounters with green activists. And if you'd said to me a few years ago, you know, I'd be talking to green activists all the time, I'd say, nah, of course I wouldn't. And I did actually end up talking to people like George Monbiot in this country, Mark Lynas, Michael Shellenberger, Ben Heard in Australia--people who really fervently believe in the environment and most of whom were, like myself, anti-nuclear. But when you actually start having a conversation, putting the evidence, the scientific evidence to them and they read that, they sort of come to the same conclusion that I did eventually that hang on, I can't really be anti-nuclear because the science is telling us that nuclear is not as bad as we think it is. So I've had many interesting conversations with people in the Green Party and actually there's a new group starting out, that is Greens for Nuclear Energy in this country. And I think people are starting to understand there is a risk to everything we do to generate energy. But actually, nuclear is probably a much better bet and less risky in terms of the environment than some of the other technologies that we use that involve carbon like oil and gas and coal, etc. So I think the Green Parties are changing their understanding because there's now so much evidence for climate change, and there's far more evidence now for the fact that low-dose radiation doesn't do what we expected it to do. It is, as you said, a weak carcinogen, though I think that many of them are starting to change their ideas.


Chris Keefer [00:23:38] Yeah, that's a perfect segue way to what I wanted to touch on next, which is the subject of radiation, because that's people's main concern with nuclear energy, from the operation of the plant, to a potential accident, to issues with the spent fuel. You know, I'm an emergency physician, and in medical school and in residency when we were talking about toxicology, the key phrase was "the dose maketh the poison." And, you know, I've actually treated someone who took a massive overdose of a chemical called dihydrogen monoxide--H2O or water. You know, for whatever reason, you drink something like eight litres of water in about an hour. And, due to the imbalance in terms of the osmolarity between his blood and his brain and the blood-brain barrier, he ended up with severe swelling of his brain (cerebral edema) and required intensive care for about three or four days. And luckily, he was discharged from the hospital. So, I mean, that's a very high dose of a pretty benign substance.


Geraldine Thomas [00:24:41] And of course, if you inhale water, it doesn't do you any good at all!


Chris Keefer [00:24:43] No, the root, I guess, is very important. But, you know, we also ingest thousands of substances every day that are in absolutely tiny doses, and that don't have any obvious effect on our physiology, or just don't have any effect. So for radiation, what do we know about what is a dangerous dose of radiation? And how do we measure it?


Geraldine Thomas [00:25:08] Well, the way I think you need to look at it, I mean the measurement--we can measure it to the nth degree, and I think that is part of the problem. Most chemical substances we can measure and then we go below a threshold level where we can't measure it any longer. It's not like that with radiation. We can measure it to the nth degree, you know; it is really something that we can characterise quite well. So you have a problem, where if you could measure any dose, it's very difficult to set a threshold. And the problem we have at the moment is that most of the data that we have comes from things like the lifespan studies in Japan, which was the studies that were set up after the atomic bombs. And what's happened with all that data is, people have basically said, well, we can measure it down to the nth degree. It's a straight line. So that gives you what's called a linear no-threshold hypothesis, which means that--it is taken as being that any dose of radiation could potentially cause a tumour. The problem is you need to put that into context with other things. So the way that I illustrate this is, the [???] report in the states is full of masses of data. And the Americans are really good because they've got huge numbers of people on databases with huge numbers of interesting information about health in general. And if you look at it this way, if we gave 100 Americans 100 millisieverts, each of radiation, one of them would be likely to get a radiation-induced cancer. Forty-two of them would get cancer from other causes. And, of course, as it's a linear response, the lower dose you go down, the more that individual dose of radiation pales into insignificance with what else causes cancers. You know, smoking, drinking, obesity, you name it. All the other things are far more effective, as the dose of radiation goes down, at giving you cancer than radiation is. So you get to a point where you think, why am I worrying about, you know, one out of four hundred and twenty is a dose of 10 millisieverts. Shouldn't I be a bit worried about more worried about finding the causes of cancer in the 420? They get it from the other sources. So it's because we have a hypothesis which we can neither prove or disprove because we are permanently surrounded by radiation in this earth, and we won't get away from that. It's really impossible to do the experiment that will work out what a tiny, tiny dose of radiation would actually do to a population, because you have to isolate people from all of the sources of radiation. You can't do that. It's very delicate.


Chris Keefer [00:27:54] I've heard that they've buried rats far underground to try to do an experiment.


Geraldine Thomas [00:27:59] Yeah, but a rat is not a human. No, and that's part of the problem. The other way to think about this is, you know, we are a species that's been around on this earth for many, many millions of years, thousands, millions of years. So we've actually evolved with radiation in our environment. And it would make sense if we were evolving with low dose radiation in our environment to have some defences against it. And once you start looking into the biology, you know, you look at all the DNA repair mechanisms and things like that, which in humans are very highly developed. So, you know, maybe we've actually got all of our defences to this very low dose. And actually, I find chemical carcinogens far more dangerous than radiation. If you smoke, you take in about--if you're smoking 40 cigarettes a day for a year, the dose to your lungs from polonium-210, which is a pure alpha emitter, is about 10 millisieverts. But that's not what gives you lung cancer. It's all the nasty chemical carcinogens that give you the lung cancer. For me, I did pharmacology and toxicology. I'm always more worried about the chemicals. These are nasty things and they don't decay in the environment. They usually hang around.


Chris Keefer [00:29:12] Yeah. I mean, I think it's interesting in terms of just, again, getting a sense of those numbers, 100 millisieverts, 10 millisieverts, and then comparing that to the doses that I routinely administer in the form of diagnostic imaging. You know, where I'll do a head C.T., which is about two millisieverts, which is, I guess, similar to the background dose of radiation that you get over a year living where I do.


Geraldine Thomas [00:29:35] And you'll get that in a dose very quickly when you give it.


Chris Keefer [00:29:39] Yes, exactly, to get it all at once. And people tend not to really object to--I mean, some doctors will really struggle with, you know, should I C.T. this younger person or not. But in general, you know, the general public certainly isn't very afraid of radiation when it is a potential benefit to them individually on a medical level, like with imaging or with cancer treatments. But when it comes to potentially a population benefit, you know, in Ontario where I live, we managed to phase out all of our coal electricity generation, which was about 25 percent of our electricity generation. We were able to do that because of the nuclear power plants that we were able to get started up again. And you know, that ended up saving thousands of lives in terms of reductions in air pollution. What are the relative risks? Again, I think I've heard you say in the past that nuclear accidents are actually not a high source of high doses of radiation to the general public.


Geraldine Thomas [00:30:40] Yeah, that that's correct. I mean, the iodine is a worry for children. But if you do what the Japanese did and cut the food chain very quickly, you know, and you make sure that kids don't drink contaminated milk and they don't eat contaminated leafy green vegetables. Then you reduce the iodine considerably--in the event of a very, very rare accident. I mean, people forget we have nuclear power now since the 1950s. And how many accidents if we really had? We've only had one that resulted in big enough levels of radio iodine to actually affect the health of the population. And that was a poor design to be fair.


Chris Keefer [00:31:17] Yeah. And the iodine, is this one of these radio isotopes, radionuclides that sticks around in the environment forever?


Geraldine Thomas [00:31:24] No, no, that's the interesting thing. All of it's gone within three months. So if you get a release of iodine, it'll all disappear in three months. It's got a halflife of of eight days. So caesium sticks around for a bit longer. Caesium-137 has a halflife of 30 years. But because it doesn't concentrate anywhere in the body and because it has that long halflife, it doesn't emit much while it's inside you. It has a biological halflife of about 100 days, the same as iodine. But because its physical halflife is that much longer, it doesn't admit much radiation while it's inside you. So there is this confusion in people's minds that is, if something is long-lived in terms of its physical radioactivity, that it must be much more dangerous because it's around for longer. But actually it means it's pretty boring and doesn't emit much radiation. It's like, you know, plutonium is something that people have big bugbears--it's the most poisonous thing known to man. Well, no, actually, you can sit and hold it in your hand inside a plastic bag or a bit of shielding. You can sit there and hold it quite happily and it won't even feel warm.


Chris Keefer [00:32:28] So one of the arguments of folks that are very concerned about low-dose radiation is this idea of a hot particle. Like if I were to inhale, you know, some uranium powder and it got into my airways and my lungs that the local dose to the tissues would be very high. Is that something that's been studied?


Geraldine Thomas [00:32:45] Well, I hate to tell you, do you swim in the sea?


Chris Keefer [00:32:49] I have.


Geraldine Thomas [00:32:50] Yeah, well there's uranium in the sea. So it doesn't--you have uranium in your body anyway, at very low levels, but you have uranium in your body. You'd have to ingest quite a lot of uranium to actually do anything. And actually, if you ingested that much, it will be the chemical toxicity that would kill you. That would be toxic to your liver and your kidneys rather than the radiation. So this focus on uranium being, you know, terribly dangerous just isn't the case. You'd have to ingest huge amounts to get it a significant radioactive dose. And by that time, it would have killed you from the chemical toxicity.


Chris Keefer [00:33:24] And when we talk about environmental sources of radiation and natural background radiation?


Geraldine Thomas [00:33:29] It all comes from uranium. You have to realise that. It starts with uranium, but you get radon produced. And in certain areas, well, the radon is much higher. For example, I got into a lot of trouble in this country by telling people that actually the radiation levels in Cornwall were higher than they were in most of Fukushima, which was true. But the Cornish tourist board didn't like me for saying that. But in some areas where you've got a lot of granite and things like that (Colorado is another good example in the States ), then you will get higher levels of radon gas being produced, which again, you can mitigate against. But most of all, background radiation actually comes from radon gas.


Chris Keefer [00:34:07] So, say, if we were in Denver, Colorado, how does that level of background radiation compare to the areas surrounding Chernobyl, for instance?


Geraldine Thomas [00:34:16] It is about six millisieverts a year that people in Colorado will get from background radiation, whereas you compare that with 10 millisieverts from caesium over a 50-year period, sorry, 25-year period in Chernobyl. You know, actually, most of the worry is not around what happens from nuclear power plants. And we shouldn't be worried about that. In fact, if you live close to it, within 80 kilometres, say, of a coal-fired plant, you'll receive more radiation than from a nuclear plant. Because when you burn coal, you release the radioactivity that's present in carbon.


Chris Keefer [00:34:55] I think one of the big barriers to nuclear energy being deployed is, you know, again, this fear of radiation and the level of regulation that arises as a result of it. And it's very hard to make an argument to the public that, hey, we should allow more "pollution" into the environment for this industry. But I think if you compare that to, you know, if we were as concerned about heavy metal pollution from broken solar panels, for instance....


Geraldine Thomas [00:35:22] Yeah, cadmium and things like that are really nasty. It's interesting. We know people focus on nuclear waste. I think that's more of where people are putting their angst at the moment. But actually, the nuclear industry is one of the few industries that actually knows what to do with this waste, packages it, and can dispose of it properly, whereas the solar panels frequently end up being broken up in poorer countries. And then you have the problems of heavy metal leaching into water causes, etc., and the actual chemical toxicity from that, which for me is worse than the radiation.


Chris Keefer [00:35:57] So, you know, a timely event for our conversation is that there was measurement, I think, by a system that's put in place to detect to see if anyone is doing nuclear weapons testing. So some very sensitive instruments. And they've picked up, I think, some caesium and ruthenium, a couple of radionuclides that are associated with civilian nuclear fission in the Baltic Sea. You know, the media. More on Twitter. I think I've seen speculation that another Chernobyl is in the making.


Geraldine Thomas [00:36:26] I don't think it's another Chernobyl; I think it's probably something to do with nuclear weapons. You know that, unfortunately, we don't know everything that goes on in everybody else's country. But the good thing about radiation is you can detect extremely low levels. And there is so much monitoring that is going on, particularly in the Baltic countries where they are closest to Russia. So they're going to want to know first if there's anything going on. There's so much monitoring going on, they'll pick up all sorts of things. And you have to remember that, you know, Russia has nuclear weapons, nuclear submarines and things like that. It isn't always something to do with nuclear power.


Chris Keefer [00:36:59] Yeah, I know they're certainly doing some nuclear rocketry recently.


Geraldine Thomas [00:37:03] That's the suspicion [as to] where some of that radiation may have come from.


Chris Keefer [00:37:08] Yeah. So you were involved in talking to the media in the aftermath of the Fukushima incident. And, you know, there was certainly a lot of harm from the tsunami and also from the evacuation itself, where I understand there were people on life support in intensive care units that were sent off in a very kind of panicked evacuation. What was your take on the impacts of the Fukushima nuclear accident?


Geraldine Thomas [00:37:37] Well, it was it was it was very funny because my kids called me through to say, Mum, Mum, go home and watch the news now! So I was watching it as it unfolded. And then the telephones started to ring and I ended up doing lots of stuff for the media. And I kept saying to people, this is a non-event. This is not going to have a major health effect. You know, the Japanese have done exactly what they're meant to do, focus on the tsunami and the earthquake. I mean, the 20,000 people lost their lives in the tsunami. And they reckon about 800-1800 people died as a result of a hurried evacuation because people were scared of the radiation.


[00:38:14] And I've actually stood in one of the old people's homes (obviously, there's nobody there now) that overlooks the power plant. And it's a concrete building. And several people from that home were evacuated and lost their lives because they didn't have adequate water and food supply and medical supplies on the buses they put them on. And they'd have been perfectly safe, if they just stayed indoors in a concrete building with windows and doors shut. It was interesting. The journalist who is there with me said, yes, but what happened if it had blown up? And I said, oh, hang on, hang on. Those are words that we use around nuclear power. It melts down. It does not blow up. What you see is the hydrogen explosion. It's not a nuclear explosion. And so what you get is the volatile chemicals coming out of a plant which are in a cloud in an airstream that passes over you. So if you shut your windows and doors and stay inside, then you'd be perfectly OK. And people can then be evacuated properly with the right medical support, etc. And when they did that, they did that in other homes, and they found they didn't lose anybody when they moved people. So it just shows that if you panic, your panic is going to be much worse than the radiation's ever going to do to you.


[00:39:27] And the key thing, if there's another one--it was interesting, we had just written an editorial for our whole journal piece that we put together because it was the 25th anniversary of Chernobyl in April and Fukushima happened in March. So everything was ready to go to press. And one of the points we made in the editorial was the one thing we have not yet learnt from Chernobyl, which we must learn, is how to communicate the real health risks of radiation better. And what did we do? Made a mess again and frightened people. And that's inexcusable. It really is inexcusable. I've taken a lot of the journalists to task after that, and many of them have now sort of said, we created all of this and feel quite guilty about it and would like to do something about it. But it's very difficult trying to now tell everybody that nuclear power is safe. And all these headlines that we saw actually have meant nothing. But what they have done is damage those communities and made them very frightened. And fear has a very bad effect on human health.


Chris Keefer [00:40:30] And in terms of the impacts on health from Fukushima, what's anticipated there and what's been seen so far?


Geraldine Thomas [00:40:38] Well, the major effects are psychological. It's people being scared of radiation. Some people still believe they're going to get acute radiation syndrome. You know, it's the inability to turn off, stop a fear becoming a phobia, that is our real issue, I think, around here. There have been no health effects in terms of the radiation simply because the doses were much lower than Chernobyl, because of the different design of reactor. It was a different climate at the time. You know, the cows were inside. They didn't drink very much milk anyway. They cut the food chain, so they limited the amount of caesium and iodine that got to the population in food, which is the major source when there's an accident like this. But people are still scared to eat food from that area. And the worst thing for me is going--I've been there, I've been to the power plant five times over the years--but the worst thing is seeing all the fantastic topsoil that used to provide the best rice in Japan is now scooped up and put in plastic bags and left on the side of a field. So they've also damaged their agriculture because they've completely ruined their topsoil as well.


Chris Keefer [00:41:44] And that was because of fears that you're seeing caesium in the soil.


Geraldine Thomas [00:41:49] Yeah. Whereas if they'd left it spread out across the land, it wouldn't have had an effect on human health. But the problem was nobody would buy their food because they didn't believe that it was healthy food any longer. It's really sad.


Chris Keefer [00:42:05] And how do you, what's your take as a science communicator on how to, I guess, rectify this extreme misunderstanding of the risks and particularly the relative risks of low-dose radiation, such as what's seen in Fukushima Prefecture?


Geraldine Thomas [00:42:22] Yeah, I think it's difficult. It's never going to be an easy thing to do because you're on the back foot. In all the time since Chernobyl--you know, we don't say anything in science until we got the evidence to say it. It takes many years to get that evidence in terms of the stochastic effects of radiation. So I think we need to be more vocal. I think it has been difficult to speak out at times because you get attacked publicly. And many scientists, particularly in Germany, I know, put the head well below the parapet because they were scared about the backlash that they would get from people if they actually said, no, this is not as bad as it looks. So I think we need to be less scared about speaking out. I think there has to be a balance in the amount of information that people have. And we have a real problem because nobody actually knows what news is genuine news any longer. So I think we have an uphill battle over this. But you have to remember that living life is risky. You cannot avoid risk in life. You just have to be able to balance those risks. That's good for you personally, but also good for society. And we have a duty to do that as scientists to keep trying to put that balance over, because it's very, very easy to get a jaundiced idea of the risks. You know, the antivaxxers and people like that. Case in point, a rise in measles. And I've seen some reports recently that people will not have the coronavirus vaccine when it finally comes out because they don't believe in vaccination. Well, that could be catastrophic because you may have a pool of people there who are going to keep that virus going. And in terms of society, the responsible thing is to have that vaccine. But if you have a significant pool of people who don't have it, we have a problem.


Chris Keefer [00:44:09] Yeah, I mean, it's another sort of tragedy of the commons there, because, you know, even if we do get a successful vaccine with longstanding immunity, it's unlikely to be as efficacious in the people who are most vulnerable and the elderly, because their immune systems are pretty worn down. So there's a even bigger benefit to younger people enthusiastically embracing the idea of protecting others and acting for the collective good.


Geraldine Thomas [00:44:35] Yeah, but it's difficult to do if a youngster. I'm speaking as one of those more elderly ones likely to appear to be in trouble. I'm diabetic and not thin. So, you know, I'm well aware that I'm in a higher-risk group, although actually I think I've already had the virus. But I had it early on--I had the classic symptoms, so I'm pretty convinced I've had it, but I have no proof that I've had it, and I've no proof that I have now got an immunity to it either. But, you know, I think we are in a very dangerous position in the way that people view scientific evidence. And it's almost as if it is actually opinion that matters, not evidence any longer. If you've got an opinion and you express it well and you are charismatic, people are going to take you at your word rather than being able to look at the proper scientific evidence. And unfortunately, most scientists aren't very good communicators. So we have a real problem. We have to get a lot better at communicating the science and explaining uncertainty. And that is difficult to do. But you can do it if you try.


Chris Keefer [00:45:37] Okay. Is it okay if I call you Gerry?


Geraldine Thomas [00:45:40] Yeah, absolutely.


Chris Keefer [00:45:41] Okay, Gerry, thank you so much. It's been a really wonderful conversation and I've certainly learnt a lot. There's many more ways to see more of Dr. Thomas's work. She has a number of YouTube videos. If you just search Geraldine Thomas on YouTube, you'll find some other excellent talks that she's given. And those really help because there's a lot of slides and visuals that go along and extracts from really high quality journals, infographics, which I find to be--talking about science communication, I find that to be a really, really useful tool to make information accessible.


Geraldine Thomas [00:46:14] Chris. I'd just say if you go to the Chernobyl Tissue Bank web pages, which is just Chernobyltissuebank.com, there is a page on podcasts and videos and also a whole load of links to information about Chernobyl, etc.


Chris Keefer [00:46:30] Okay, Gerry, thank you so much again for coming on, and I look forward to maybe speaking with you again in the future.


Geraldine Thomas [00:46:35] Thanks very much, Chris.


Chris Keefer [00:46:36] Okay, bye for now.


[00:46:44] If you enjoyed the podcast, please make sure to subscribe, like and review us on your podcast platform of choice. Until next time, guys.