A.P. Moller, abundance, academic research, animals, Austria, Belarus, biodiversity, biological consequences nuclear disaster, biology, birds, butterflies, cattle, Chernobyl, Chernobyl wolves, children, chromosome breakage, CNRS, comet assay, cows, crickets, dangers of nuclear, DNA fingerprint markers, dosimeter, dragon flies, Europe, evacuation zone, evidence based science policy energy environment, evolution, fitness, Fukushima, Geiger counter, genetic damage, grasshoppers, gray hair, Hanford, high frequency nuclear disaster, hypotheses, IAEA, insects, Italy, Kiev, logic, methodology, methods, mice, mutation rates, mutations, nuclear clean-up, nuclear energy, nuclear power, nuclear waste, partial albino, people, plants, radiation decline in diversity, radiation decline in wildlife abundance, radiation dose, radiation levels, radiation zone, Research, risk, Russia, scientific method, scientific research, Scotland, sheep contaminated, Stress, survival, swallows, Three Mile Island, Timothy Mousseau, tritium, U. of South Carolina, UK, Ukraine, Vermont Yankee, voles, white spots Fukushima cattle, wildlife decline Chernobyl
Slides from Mousseau’s May 2014 presentation at the US Library of Congress: “Biological Consequences of Nuclear Disasters: From Chernobyl to Fukushima, LOC-Mousseau ” http://youtu.be/NSO4ZoY7GT0
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Today’s event is organized by Science Technology and Business Division of this Library of Congress. I’m Tomoko Steen, research specialist here at the Library of Congress. Today’s speaker, Tim Mousseau, maybe I should say Professor Tim Mousseau, is currently professor at the Department of Biological Sciences, University of South Carolina. He has a Ph.D. from McGill University in Canada. And he has served as the Dean of the Graduate School, Associate Vice President for Research and Graduate Education at the University of South Carolina. And he also was in the Washington area. He was a Program Officer at NSF, National Science Foundation. He serves on many editorial boards for both domestic and international scientific journals. And he was also on the advisory panel for NSF, USGS and a wide variety of agencies. And also international grant foundations. He has over 160 publications, probably a lot more now, but also 2 published edited books, published by Oxford University Press. And he’s also co-editor of the annual review series, “The Year in Evolutionary Biology”. I have one copy on Chernobyl in the back there… Since 1999, Professor Mousseau has been collaborating with colleagues from CNRS and the University of Paris, working on these cases of Chernobyl, especially focusing on the biological effects of radiation, various species, birds, insects and people. And now his focus is Fukushima and comparing his data with Chernobyl to Fukushima. So before further adieu… please join me in welcoming Professor Mousseau.
^M00:03:10 It really is an honor and a privilege to be here today in the bright lights as it were and to be your lunchtime entertainment. I really welcome the opportunity to do this.
Today I’m going to give you a very, very brief overview, rather superficial overview of the work we’ve been doing in Chernobyl and more recently in Fukushima. And this slide here to begin with is just to remind me to acknowledge my partner in all of this research, Anders Moller at CNRS in France who’s been a major inspiration for a lot of what we do. And of course all of our funding agencies we need to thank them first and foremost.
Prior to three years ago I used to get the question all the time, so why are you studying Chernobyl? It could never happen again. You know it was a unique event, world history, we’ll never see anything like this again. And of course Fukushima hit three years ago, March 11th and so it’s a little bit easier to answer this question now.
But let me give you a brief review of why it’s important that we invest in research, basic research related to these events. The first really comes from the fact that we are, no matter what you think of nuclear energy, we are completely dependent on nuclear energy on a global scale.
There have been more than 600 commercial nuclear power plants since the beginning of time, in the 1950s. They’re currently about 435 nuclear power plants in 31 countries, 62 in the U.S. And 17 new reactors are under construction in 15 countries right now, but half of them in China of course.
In this time there have been three major nuclear accidents at commercial plants, not including the military accidents or the accidents at refineries or things like that. These are just the energy generating plants.
Starting first with Three Mile Island in 1979. Most of us in the room are familiar with that one. And Chernobyl, 1986, 28 years ago and of course Fukushima 2011. So that’s three out of 600.
It’s kind of a, I don’t know, any statisticians in the room? What, what’s the probability there? I don’t know if any of you would get on an airplane if there was a 1 in 200 chance of it crashing.
But anyway, fairly high frequency of these kinds of disasters no matter how you look at it. There have been 33 serious incidents and accidents at nuclear power plants since 1952. And yet given this, what I would consider to be a relatively high frequency of significant accidents and incidents, there’s relatively little known about the biological consequences. Certainly lots of controversy around it, lots of discussions as well as the health consequences for humans. So that’s one good reason for doing this.
The other is that all these nuclear power plants, there’s a bunch of new ones being built but most of them out there are quite old, 30, 40 years old. And, you know, any of you with a 30 or 40 year old car, 10 year old car, know that mechanical equipment deteriorates if it’s not properly maintained. And sometimes you can’t really maintain it. So, there’ve been quite a number of revelations in the last few years about break downs at the, some of these power plants. The most famous recently, The Vermont Yankee Plant, where they discovered tritium leaking, significant amounts of tritium leaking offsite. So, nobody really cared too much when the tritium was contained within the borders of the power plant. But when it, once it starts getting offsite, the potential for it to get into the ground water and to effect drinking water is significant. And there’s also the fact that we know very little about what the potential ecological and environmental health consequences of tritium leaks might be. We all think that they’re probably minimal given the small amounts that are leaking but we really don’t know what they are. And of course, once they discovered this one they discovered that probably half of the power plants across the country were leaking more than they were supposed to. So it’s a significant issue.
Another one, another reason for being interested in the facts of environmental radioactive contaminants, of course we have all of these cold war era relics sitting around across the country. This is the most famous of course, the Hanford Site where they have hundreds of millions of gallons of radioactive waste. And the expense so far, 40 billion dollars have been spent, 40 billion dollars have been spent on trying to patch things up. They’re anticipating at least 115 billion more will be needed before they’ve got this under control. And of course you know how government spending goes. It’s probably going to be a lot more of that in the end.
All right, so Chernobyl 1986, we just had the anniversary not too long ago, 28 years ago. Major catastrophe, lots of design problems, human errors but, you know, there’s lots of discussion of that. The fact is it happened. Nuclear fire burned for ten days. Released absolutely enormous amounts of radioactive contaminants both in the form of fission products as well as in the form of particles of unspent fuel plutonium released, scattered across the environment. Most of it of course is in Ukraine and Belarus and parts of Southwestern Russia. But also vast areas of Scandinavia were significantly contaminated. Ironically parts of Austria near the International Atomic Energy Agency offices, Northern Italy and even parts of the UK up in Scotland were affected to the point that they couldn’t eat the animals, they couldn’t harvest the sheep for instance. So vast areas. About 200,000 square kilometers at minimum were contaminated.
Fukushima, the second largest disaster. Probably, you know, if you had to, you know, ball park it you would say that it was about 1/10 the size in terms of the impact to terrestrial systems. Of course we have no idea what the impacts will be on the marine side. Again very little research is being done there other than to catch a few fish now and then and see how radioactive they are. And a little bit of modeling going on to see where these contaminants might end up. But not a whole lot of investment really. But here’s a map, a citizen scientist generated map of contamination about a year after the event. You can see this part of Fukushima very highly contaminated. But even parts of Northern Tokyo have quite significant levels of contamination that certainly most of us in this room would not want to experience on a prolonged basis. I think a short visit is not a problem but at least to my mind but not everybody feels that way either.
So we started working in Chernobyl in 2000 as a team, Anders and I. And we’d both been there before then and we decided this would be an interesting place to potentially discover new kinds of adaptations in plants and animals.
We also began work in Fukushima in July 2011, three or four months after the disaster. Again mostly populations of birds, insects, microbes, mammals, just about mostly everything except people.
Although we have started a small project in collaboration with the hospital in Kiev looking at a cohort of children because they found many parallels to what we found with the animals and so they’re interested in maybe pairing some of these studies.
More than 30 research expeditions to Chernobyl, 10 to Fukushima so far, more than 60 papers just on Chernobyl, Fukushima.
And you can find most of them on my Website if you’re at all interested in seeing these papers [http://cricket.biol.sc.edu/Mousseau/Mousseau.html]
I make this point at every talk because I frequently, I don’t know why but I frequently get invited to speak to anti-nuclear activist groups. Some of my best friends but, you know, I make the point of we are independent biologists. We don’t have a dog in this race as it were.
And we’re mostly interested in the biological consequences of elevated mutation rates which is something that evolutionary biologists have not been able to really look at beyond a laboratory setting. And so being able to look at this, the effects of mutation inputs in a field setting at a landscape scale is kind of a unique opportunity for evolutionary biologists. I did discover recently that I am indeed an activist but I’m an activist for evidence based science policy as it relates to energy in the environment.
So, as a biologist, as an active scientist of course, we frame everything that we do in the context of hypotheses and questions. We try to be logical about it. And I’m not going to spend a lot of time at this but I just want to show you the chain of thought as it were involved in the logical progression in what we do.
You know, the first question is, you know, do, does the radiation levels, do the radiation levels that exist in Chernobyl and Fukushima, do they do anything?
Are they high enough to cause increased mutation rates in natural populations? You might think that would be a given but it’s, you know, there were lots of questions about this and so that’s one of the, been one of the priorities for us is to document what kind of, what amount of genetic damage occurs as a result of the exposures that are there.
Are there consequences? You know, we all have mutations inside our bodies and many of them don’t do anything. They’re not expressed, they’re just sort of neutral as it were or slightly neutral. Dr. Steen can tell you about that. So you need to know whether or not these mutations have any meaning to the, to the animal. Particularly in terms of whether it has any meaning to the fitness of the animal. Does it affect its survival? Does it affect its ability to reproduce? Does it affect its susceptibility to disease and that kind of thing? You need to know this for it to really matter to make any difference. Finally, you know again, well not finally but again as ecologists we’re quite interested in the notion of can there be adaptation? Will there be adaptation? In much the way that we’re interested in whether or not plants and animals can adapt to climate change right now. That’s a big topic as it were. We’re interested in knowing whether or not there can be adaptation to elevated radiation levels. And I’ll talk a little bit about that. Are there effects at the, you know, at the ecological scale on abundances in biodiversity? And finally are there effects on ecosystem functioning? Do the ecosystem services that we all rely on for generating clean water and food and building materials, are they effected in some significant way as a consequence of these kinds of disasters? I have to say that, you know, apart from the novelty we were also motivated by statements published by the International Atomic Energy Agency and their Chernobyl form reports from about 10 years ago. And in this reports they actually suggest with these words that the plants and animals inside the zone are actually, and you’ve probably all heard this. The plants and animals inside the zone are actually thriving. They’re doing great because there’s a fence and there’s no people. And by implication because the radiation has no effect, right? And so we were intrigued by this notion. And so we wanted to see for ourselves. And we wanted to, turns out there wasn’t a lot of data for it but there were, you know, lots of newspaper reports, you know. Chernobyl becomes a wildlife haven. Maybe you’ve seen, you know, the video, Radioactive Wolves and, you know, Disney Channel has these kind of Cinderella stories for Chernobyl on a regular basis. And we, but there, when we went to look for it there wasn’t any quantitative scientific data published. This was really all anecdotally based. And so this motivated us. We knew that we could, whatever we found would be publishable. So we decided to get to it.
And as I mentioned, most of our work has been with animal models, mostly birds because they’re easier to see than most other animals. And a lot’s known about birds. But also because I’ve never seen a barn swallow drinking vodka or smoking cigarettes. And as far I know they don’t get stressed out from the disaster which has been used as one of the, you know, stress is an important component of human disease. We all know this. But the animals don’t get stressed out from this and so we’re presuming that if we do find things that are related to, you know, effects that are related to the radiation, it’s not due to stress. I’ll just leave it at that. And also because the animals don’t respect the fence, you know, they come and go, we do find animals, some animals to play with, to observe even in the most radioactive areas. So, that gives us the range of variance that we need to do the statistically analyses that are needed for scientific study. We most recently, we just recently started a new project in Fukushima with cows. Turns out the farmers inside the zone, some of the farmers have not wanted to give up their cows for a number of reasons. And many of these cows are living in very, very contaminated areas. It’s not a great photo but this is 125 microsieverts per hour at this location where there are a bunch of cows. So that’s, you know, about twice that level, chronic exposure is likely to significantly affect you in you know, two, three years. It’s a very high level of radiation. So this is an opportunity to study what’s going on and we’ve taken it. So the first question you have to ask, the first question I’m always asked by the physicists in the crowd, any physicists here today? Okay, this is for you. How much of a dose are these animals getting? You know, every paper we’ve published I get asked this question. And so we’ve had to take it seriously. Health physics is most concerned about dose. Nuclear physicists are most concerned about the dose. We’re not so interested in dose because of the way we do our studies but we are interested in knowing if it’s a high, medium or low dose. And so we’ve actually made a lot of progress in this area.
The first thing you have to do is you have to catch the animals. And so we string out large numbers of nets along forest sides and we bring them into our makeshift laboratories inside the zone. And the best part about this work is actually that we get to see these animals that people rarely see. This is a wryneck. It’s a snake mimic.
It lives in holes of trees and if something comes in and bugs it it’ll stick out his neck like a snake and try to poke at it. And lots of really interesting critters. So anyway we put out, when we were doing these we put out 1/3 of a mile worth of nets and catcher. We’ve caught thousands and thousands of birds.
And we started putting little dosimeters, miniature dosimeters on the birds.
And, you know, we put out thousands of these now. And we can, we get back between 10 and 20 percent of them will come back when we need them. And so we can get an estimate of what dose, external dose they’re getting.
We’ve also done this with mice, little collars around their necks with little dosimeters. They’re very cute.
They will bite though and they are so stinky. Oh, I had no idea mice were so stinky. And cows are much easier of course you can, you know, you can put a dosimeter on a cow, you can put anything. You can put, we put GPS and activity sensors and all sorts of things on cows. That’s one of the great things.
The other great thing about cows is their easier to catch than birds. You know, if you ring the dinner bell, the cows come running. You know, they just stampede looking for that treat for dinner. And so they’re much easier to work with. And of course they give big samples.
We also get internal body burdens by sticking the mice and birds inside a little lead cave with a gamma spectrometer and we can get the, an estimate of the dose. This was an early version of our setup. We have a much more advanced version now but it worked fine.
Basically, you know, 4 or 500 pounds of lead is the minimum you need. And with cows of course you can’t stick the cows inside there but you can take a blood sample that’s large enough to get readings of just how much internal dose they’re getting or approximately. The veterinarians have figured out how to do this.
The good news for us is that it turns out that the birds at least and probably for the cows, you can take your handheld Geiger counter, your $400 Geiger counter and put it on the ground in the area of interest where the bird is caught. And this is actually a very good predictor of the external dose it’s getting. During the time of the year that we’re doing the work with these birds, they’re quite territorial, they’re right very close to their nests. And so when we catch them we catch them close to their nests and that actually is a very good predictor of what they’re getting. So we can combine these different measures of radiation and come up with a dose for these animals fairly well.
All right, that’s how we know the doses. So the first step, mutation rights. Does it matter? Do these doses that they’re getting lead to genetic damage of some sort or another? First question. And so to get at this we’ve used, you know, a wide number of different approaches. There’s no one best way to do it. Well there are some best ways but the best ways of course are extremely expensive so we don’t use those yet. But we have used DNA fingerprint markers. The same kinds of fingerprints that the police use and the FBI use for forensic analysis. We can use it, use these kinds of markers on the birds. And we have used them to show that mutation rates are increased 2 to 10 times.
Another approach that we use a lot because it can be used on any animal without too much development time and cost, so called comet assay. I’ll show you a picture in a second. We also do other standard radiation tests that have been tried and true and have worked for these kinds of studies for eons. And we were also using proxies for genetic damage like damage to the sperm. We would like to get into gene expression and whole genome scans but, you know, there’s still measured in terms of hundreds of thousands of dollars to get a project off the ground which we don’t have at this point. So the comet assay though is one that’s relatively inexpensive. Once you have the microscope we do this a lot. And you basically take a single cell and as long as it’s got a nucleus with DNA in it you can make it work for this test. And basically what you’re looking for are the effects of radiation on chromosomes. When the radiation hits chromosomes it breaks the chromosomes if it’s, if there’s enough of it. And you end up with little pieces of chromosomes in the nucleus where there was once big chromosomes, intact chromosomes, then you end up with little pieces. You put it under an electric field in a gel under a microscope, label the DNA. And low and behold if the chromosomes have been damaged basically all the pieces migrate out into a comet tail as it were. Hence the name comet assay.
And so when you use this approach which we’ve done for dozens of species now, you see this very nice clear pattern.
In areas of higher contamination there are higher levels of genetic damage for lots of things. These are my crickets, grasshoppers, dragon flies, butterflies, mice, people, anything at all. And the other real positive aspect is that you can if your Dean is nice and buys you a microscope with a robot attached to it, you can scan thousands and thousands of samples in a short period of time which is what we’ve done.
So without going through all the dirty details of all the other studies, this graph summarizes the results of more than 50 studies looking at genetic damage in Chernobyl. It’s a meta-analysis. It’s a way of combining the results of disparate studies done at different systems, different times into some kind of cohesive test of a single hypothesis. In this case, does radiation lead to genetic damage in Chernobyl is the hypothesis? And these are, this is the frequency distribution basically of effect sizes. And this is the zero line here. And the basic answer is that overwhelmingly from, you know, the 50 plus studies that happened on genetic damage is associated with radiation exposure in Chernobyl. It’s, you know, the question is answered.
All right, so now that we know that there’s increase mutation rates, does it matter? Maybe none of it matters. The first visit to Chernobyl, you know, we were just kind of exploring, looking for in the case, the case, the first visit we were looking for barn-swallows because they’re relatively easy to find. If you find a barn, a cattle, a dairy farm, you can find swallows. And even if you find an abandoned farm you can still find swallows because they will keep coming to the same place year after year after year as long as their alive. And so the first thing we noticed after catching these birds is that some of them had patches of white feathers, what we call partial albinos. And when we started looking a little more detailed, about 20 percent of the birds in radioactive areas had the, were these partial albinos whereas in clean areas it was usually less than 1 percent.
And, you know, I don’t think it hurt the bird but again it was sort of biomarker for radiation exposure. And, you know, we’ve published a couple of times on that and I’m not going to bore you with the statistics. You can find the paper on my Website. It’s published in, the latest one was published in mutation research last year.
So what about Fukushima? Well we started monitoring barn swallow populations in Fukushima. And low and behold this was the first one I found. Here’s a male barn swallow, he’s got a little patch of white feathers. We only see in this in Chernobyl on any kind of frequency anywhere else. So kind of hints that there might be something to this radiation as the cause of this.
Some of the Japanese amateur scientists and scientists have been helping us to track these. And here’s another example of a bird, a barn swallow with again the same kinds of patches of white feathers that we really only see in Chernobyl. And then last year they actually were fairly methodical and found 15 cases of these partial albinos in about 70 or 80 barn swallows. So about the same frequency as we see in Chernobyl in the radioactive areas. Fairly strong evidence that, that this is good biomarker for radiation exposure.
I apologize for showing the rear end of a cow. It doesn’t reflect on the quality of science. The cows, if you look read, if you’ve been following this story, many of the cows in the radioactive areas also have these white spots.
Now the veterinarians will say oh, it’s because they have a micronutrient shortage, maybe zinc. But the truth is nobody’s really investigated this carefully to see if that really is the case. And so we’re hoping to get at these questions as well. Where did the spots come from on Bessie the cow?
We’ve also been using, I don’t know if this is appropriate lunchtime subject for the LOC. You’re all above 18 I hope. We’ve been using sperm again sperm, the gamete, the male gamete, the germ line that’s passed from one generation to the next. It has the DNA packaged inside. Damage to sperm will be transmitted if it’s viable, will be transmitted to the next generation. And this is, it’s one thing to get a cancer and have disease associated with that in it but it ends in that carrier. But it’s another for genetic damage to get passed to the next generations because it can affect many, many more individuals if it spreads as it were. And we all know a lot about genetic diseases.
So we, we developed a method to extract using a very special massaging technique, fresh sperm from these birds. It actually had been written about in the turn of the last century by some budgie, budgie fanciers as they call themselves, bird keepers who were breeding these little budgies. They needed to do artificial insemination and they developed this method. But nobody, it had been lost to the world until my colleague Anders discovered it and started applying it to our birds. And sure enough it allows us to get tiny, tiny minute amounts of the material. And we can actually look at the morphology of the sperm. We can look at the behavior of the sperm. And there are large effects on both. This is again, this is a fresh sample from a bird from Chernobyl with a microscope, in the field running on a generator. And but we get a lot of information from it. And the main observation for the behavior was that it’s the combination of radiation, increasing radiation plus oxidative stress. And this will be a little bit of a theme. Oxidative stress, so the lack of antioxidants is one way you can have oxidative stress. The combination of the two lead to the most abhorrent behavior in the sperm of many of these different birds. We’ve also again found many cases of abnormally shaped sized sperm.
Much higher levels in Chernobyl than elsewhere. So this is a study again just published last year showing the frequency of abnormal sperm in clean areas, in Europe versus Chernobyl. And we weren’t too picky about where they were. So this was just hot and cold comparison. The, in 9 of the 10 species where we had samples from both, much greater rates of abnormal sperm in these birds. So again another marker for radiation exposure.
Given that this is, you know, a key ingredient for fertility, you know, if you have bum sperm you’re not going to do well as a male in the evolutionary sense. And so this is an important measure of potential fitness for males.
Another discovery, this is currently in review, and most of you, you know, if you follow the cancer treatment literature at all you know that if you’re going in for cancer treatment, radiation therapy, they tell you bank your sperm if you’re thinking of having kids, right. Because there’s a good chance that you’ll either be temporarily or permanently sterile as a result of that cancer treatment. Well it turns out in the hottest parts of the Chernobyl zone almost 40 percent of the birds are sterile, the male birds. And so again this drops off to basically zero in the clean areas. And so this is again a very striking observation, parallels to what we see in the human population as well in Chernobyl.
You know, everybody talks about tumors. We started counting the birds carefully. You know, cancers and tumors and some of these other diseases are relatively rare diseases. Even when they’re common, they’re not very common if you know what I mean. And so it wasn’t until we had counted, collected, handled, observed a couple thousand of these birds that we started to an idea of the what the frequency of these different abnormalities might be. And when we did this we realized again in these Chernobyl areas, dramatically higher levels of tumors. Many of them on the head and around the eyes but also on the chin, here’s another example here.
Some strange developmental abnormalities as well again often where the birds are being exposed I suspect. But just strange kinds of growths that are almost never seen in normal populations. So again dramatically elevated frequency of these things, these kinds of things. And again this was published last year.
Another example, you know, again one of the striking observations from the lifespan study of Hiroshima and Nagasaki survivors was the very high frequency of cataracts. Radiation, turns out cataracts in eyes, eyes are very sensitive to radiation. And it turns out that, it turns out that the stem cells, maybe you didn’t know this, your, the lens of your eyes is completely being, is being grown all the time. There’s new layers of cells being put down all the time and at the back of the posterior portion of the lens. And the stem cells that generate these clear cells for the lens are very sensitive to radiation. And so if they’re damaged as a result of the radiation they end up making opaque cells. And so it’s very easy to see this signal of radiation damage in the form of a radiation cataract and noticed in many of the atomic bomb survivors but also in people who work around x-ray machines in the medical field or in other, nuclear industry.
And so we decided well what the heck, what’s going on with the birds? You know, we should see it in the birds if it’s real. If there are radiation effects we should see cataracts in birds as well. Nobody had looked before.
And sure enough though, again not real common. You can imagine that a bird with a cataract, a serious cataract probably ain’t going to live too long, right? So the frequency isn’t extremely high, you know, 2, 3, 4 percent maximum. But again nobody had looked before and very strong sort of dose response relationship much more, much higher likelihood of seeing cataracts in these birds in the higher radiation areas. Again, I know this doesn’t look like much but this is very highly significant relationship in terms of the probability of seeing cataracts in, is much higher in these areas of higher radiation.
We started working with, we got a grant, we got a big grant from the Academy of Finland. I was kind of hoping for a big grant from the Department of Energy but the Academy of Finland came through. And they working in collaboration with some folks in Finland and France and Portugal and to work on the rodents in both Chernobyl and Fukushima. And so we started doing many of the same kinds of things that we’ve been doing with birds with these mice and voles. And be damned if, you know, the third or fourth mouse I pulled out of the box in this first trip to Chernobyl, we find a mouse with a great big cataract and very striking.
Of course out of the 300 mice I caught that week, we caught that week, this was the only one that had this major a cataract. But we did actually measure the opacity, the lack of clarity in the lenses after we’d finished working with the other aspects of the mice. And found again very striking significant relationship between the frequency of cataracts, the degree of cataract and background radiation but only for females, not in males in this case.
This is a preliminary study so we’ll see if it holds up in the next year or two. But it is kind of interesting.
A couple years ago we started measuring the size of the birds’ heads. We’d done some work showing that the brain size in the bird is very tightly correlated to the head measurements. This is sort of typical of birds where minimizing weight, minimizing size, maximizing aerodynamics is a key factor. And so we started measuring all this and we found that low and behold, birds inside the Chernobyl zone are, have brain sizes about 5 percent smaller. No effect, no big effect on body size but the brain size, relative brain size 5 percent smaller. And this wasn’t surprising when we started talking to people because of the known effects of radiation on neurological development. It turns out neurological tissue is well known to be quite sensitive to the effects of radiation, more sensitive than most other tissues. It had been observed in children in Belarus as well but of course nobody wanted to ascribe radiation as the source of that. But, just to skip over the statistics.
The other thing we learned though is that for a bird, 5 percent decrease in brain size is important. You might have thought it might not be but turns out that the birds with the larger brains were the ones that were more likely to survive from one year to the next. The birds with the smaller brains were much more likely to die from one year to the next. So they were obviously cognitive in fitness effects as a consequence of this brain size.
In fact when we look at the rodents, we started looking at the rodents, same effect. Smaller brains in the more radioactive areas.
For these one’s we actually dissected out the brains and measured them. I do want to mention that the, for the bird work, we did not hurt any of the birds. The birds were all released live, no effects. The rodents were a different issue.
I don’t know if any of you read the Smithsonian Magazine. They published some of my photos a few weeks ago, actually online. The point I wanted to make with this, this series was that when you start looking and measuring and using the scientific method to approach these questions, there’s, you know, every rock we turn over we find some signal of the consequences of the radiation. This one’s, this one’s, being an entomologist by training I was quite interested in this one. This is a firebug, very common in Europe, common in Chernobyl.
Can you all see the face mask? Sort of looks like a face mask, you can see the, you know, sort of upside down, its nose, its eyes. And just to make it easier, you know, it’s pretty clear, you see that face mask? That’s a normal looking firebug.
And we go to Chernobyl, we go to the radioactive areas this is the range. We see about, you know, 20, 30 percent of the firebugs in the more contaminated areas have gross deformities of their, of the color patterns.
We don’t know about their genetics yet. We haven’t tested that but, you know, everywhere you look you see a signal of the consequences of the mutigenetic effects in radiation in the environment.
Okay, we really, I need, just one more class of observations to discuss. And that is the question of impacts on abundance in biodiversity. As I mentioned at the beginning, it had been suggested by the International Atomic Energy Agency that the animals were thriving in the zone. That there were, you know, you couldn’t keep, you couldn’t count them there were so many of them. And anecdotal reports in the media, movies, videos, and so we decided okay well let’s go do the hard work. Let’s go count them. And it turns out Chernobyl and Fukushima to a lesser extent but are ideally suited to test these kinds of hypotheses. And the reason is that is that this radiation, the radioactive contaminants were dumped in a very patchy way. It’s kind of a mosaic or a quilt work of contamination where you have very hot areas here and here and here and here and up here and then you have areas right here that are inside the zone absolutely clean, perfectly pristine. In fact the background radiation levels in some of these areas are lower than they are in this building simply because this part of the world has very low natural levels of background radiation because of the geology of the region.
And so by comparing this and this and this and this and this and this doing large numbers of samples, our observations across this mosaic we could get at these questions of abundance and radiation effect fairly rigorously. Here’s a larger scale so we’ve also replicated what I’m going to talk about in Ukraine over here as well as in Belarus in a completely independent area which has actually more people as well so we can look at the effects of people versus non-people.
And in Fukushima, again the same kind of, same kind of thing. It’s not quite as heterogeneous in Fukushima. It is on a micro scale but you do get hot and cold areas in fairly close proximity. Same kind of habitat, same kinds of environment, same species living in these areas so you can compare hot and cold areas repeatedly.
We employ what I call a massively replicated biotic inventory approach. It’s kind of a long name. But basically as we go to, we go to 400 locations in Fukushima and about 300 locations in Chernobyl. We’ve been to each of these 3 times now so far, and we basically count everything we see and identify everything we see at these 3 and 400 locations. We also measure everything else that might be important to determining whether a bird is there or not. What kind of trees there? Is there water there? What’s the ground cover like? What’s the soil type? What’s the pH of the soil? Basically everything that’s measurable in a relatively short period of time as well as the radiation level. And we do some GIS kind of things and multivariate statistics.
And this allows us to factor out in a very sensitive manner whether or not there is as many animals as there should be of a given species at a given location. And what proportion the variation or the deviation from prediction from expectation is due to radiation? And we do this, turns out that in the hotter parts of Chernobyl abundance is depressed by 2/3. There’s on 1/3 as many birds as there should be living in these hot areas.
So if you went there you’d still see a few birds. And you might go oh, looks kind of normal. But when you go and count them and you relate this to the radiation and everything else that’s important, very, very strong signal, only 1/3 as many birds, about 1/2 as many species of birds in the area. So big effects on the abundance of biodiversity of birds.
But it’s not just birds. Spiders, again very few in the hot areas.
Grasshoppers, fewer in the hot areas.
Dragonflies, fewer in the hot areas.
Bumblebees are quite sensitive it turns out and missing from the hot areas.
Butterflies missing from the hot areas.
And the question everybody asks of course is what about the mammals? To get at this we went and tracked animals in the wintertime. Not much fun but we can do this. Anybody have any idea what that footprint is? It’s a wolf, yeah, it’s a wolf. Look at the size of this thing. It’s huge. There are wolves inside the zone. But when you look at the entire assemblage of mammals using this technique, many fewer mammals especially the smaller mammals in the hot areas.
Here’s one looking just at the voles. Aren’t they cute? And basically when you get to above 10 microsieverts per hour, there are no voles in any part of the zone. They seem to be quite sensitive.
They like to eat mushrooms that tend to concentrate the [inaudible] radiocesium.
So we convinced at least BBC, I’m not sure we convinced anybody else but we convinced BBC that it’s not a wildlife haven in the radioactive parts of the zone. The clean parts of the zone are just fine. But the radioactive parts of the zone are depopulated. We went to Fukushima, we did the same kind of study and a little bit more intensively really. Published a paper on it last year. Since I’m running out of time I’m just going to skip ahead and tell you the bottom, the punch line is that in Fukushima we see strong negative effects on birds and butterflies and cicadas in the first year, in the first few months.
But no effect on grasshoppers, bees and dragonflies. In fact the spiders in Fukushima that first summer after the event increased in numbers. Anybody have any idea why spiders might go up? The birds are missing, yeah, you know, the birds are their main predators on spiders. That’s our guess. We have tested that. That’s our hypotheses. We’ll try and test it. We’ll see what happens in the coming years.
But it turns out that the effect on birds, there are 14 species of birds that are found in both Chernobyl and in Fukushima, same species. And when we compare the relationship between decline in abundance versus radiation the effect is about twice as strong in Fukushima as we currently see in Chernobyl.
And this lead somebody, some journalist who suggests, I didn’t say this but the journalist came up with this all on his own. Good journalist. He’s provided a lot of inspiration. Suggested that maybe this difference was because of adaptation going on in Chernobyl where there’s been, you know, more than 20 generations. And so actually we decided we would test this a little bit more carefully. And we just published a paper last week actually. It came out and hot off the presses where we looked at the birds that seemed to be doing okay. So we couldn’t look obviously we couldn’t test the birds that are missing from Chernobyl in the hot areas because they’re missing, right? So you don’t know what you don’t know. But we couldn’t look at them but the ones that are there, the one’s that appear to be surviving we looked carefully at their biochemistry and the genetic damage. And low and behold, turns out that of the ones that are there, if they are capable of allocating to antioxidants, to defense against ionizing radiation, they have lower levels of genetic damage. This was the main finding of this paper. It got us a little bit of attention. It’s funny they’d written this article before this paper came out but they, they liked that happy ending to the story so much they had to go change all the headlines. But anyway, I’m not going to bother you with the graph too much but suffice it to say that it, what it’s trying to show in a very complicated way is that the birds that manage to allocate antioxidants, in this case GSH, to defense against oxidative stress induced by radiation. Those birds have lower level of genetic damage and that appears to be responsible for their success.
But there’s smaller brain, yeah? Well little bit smaller brain for some of them, yeah. And, you know, we need to do the experiments, you know. We need to do the experimental work to go on with this. This is correlational, so it’s just a first stab at this. But it certainly points to something that’s worth pursuing. So just to finish up.
So, what did we find? We found that most organisms show significantly increase rates of genetic damage where it’s radioactive, no surprise there. Most, many of the organisms show increased rates of deformities and other kinds of developmental abnormalities again in proportion to the contamination levels, reduced fertilities, shortened lifespans. I didn’t talk about that but we have data on this. Reduced population sizes and reduced biodiversity in many of these hot areas.
Some other more interesting speculative suggestions are that there may be in some groups, there’s some evidence of sort of amplification, magnification of genetic damage because of chronic multigenerational exposure to the radiation. There’s some people, there are folks in Japan who have been working on this question and shown that this indeed happens for some butterflies and some mice under some sets of conditions. So it’s certainly worth pursuing. And then the other issue of potential importance is the fact that because this radiation is low dose radiation, it doesn’t kill the animals immediately. Most of the animals do not die as a direct result of the radiation and some other consequence. They live long enough to move as animals do. And so there’s migration of this genetic damage outside of the zone.
Good news, there’s not much good news, but it’s, you know, there’s some evidence that, that natural selection is working to improve response for some of these species. We don’t know whether it will continue in the future. We don’t know what’s happening in Japan for the critters that are there. And let me just end with this then that I’d like, I’d like the next headlines to be something like this, you know. Basic scientific research reveals hidden effects of radiation that may be of general relevance for energy and health policy. That’s what we’re trying to do. And of course the one after that we’d like to see as would all of us in this room I’m sure. Thank you very much.
[audience applause ]
Yes go ahead.
[inaudible audience question ]
Yeah, so good question. The question was really given that we’re seeing similar consequences in both Chernobyl and Fukushima, even though Fukushima was a much smaller event at least on the terrestrial side, does this imply that there is some threshold below which there are no effects? The short answer is well let me just start by clarifying. We have very little information, almost no information concerning developmental genetic effects in Fukushima. That’s just starting. We have some of the ecological observations, the population sizes but the genetic stuff is just coming in. So we don’t know what’s going on at that level very well. But all of our data is consistent with, it may not be a linear response but there’s certainly no evidence of a threshold response. There’s no evidence that the effect disappears below a certain level. It disappears but it disappears into the noise as it becomes harder and harder to detect any kind of signal given the noise that exists at these lower levels. So sample sizes would need to be larger if we were to really just, you know, attempt to figure out whether that was a some kind of gradual linear response or a threshold response. But there’s no evidence of a threshold.
Certainly we see strong statistically significant signals at the levels of, you know, half a microsievert per hour which was set 4, 5 millisieverts per year. So that’s not really, that’s a pretty low level and we still see detectable effects on most of these things. They’re obvious and there’s no reason to expect that they’re fading away. They just become less important, less smaller in size.
Yes, I was struck by the fact that you saw albinism in two different species. And I was wondering do you have a sense of correlating the effects in particular parts of the genome for both of those species? I mean is it, does it exist in the same areas or?
So the question relates to the fact that we see these kinds of partial albinism in multiple species. In fact not just two but many species of birds, cows. We’ve seen some color changes in the mice as well, although we haven’t seen any of these kinds of partial albinos so far. But the suggestion is that the common mechanism related to this, it relates to melanin production, the melanocyte cells. The suggestion is that they are very, one suggestion from chicken research is that they’re quite sensitive to oxidative stress and are among the first cells to perish as a result of oxidative stress. And hence white spots emerge where the melanocytes disappear. This last paper showing adaptation, I didn’t have time to go into the details but it turns out that melanin comes in three forms in most animals. One is in neurological tissue and then the other two come in, in ectoderm I guess in the skin and feathers. Pheomelanin and eumelanin are the two dominant forms of melanin. Pheomelanin leads to reddish colors, sort of reddish chest, nutty brown colors. And then eumelanin makes the darker browns and blacks. And so it turns out that if this cascade is driven by antioxidants. GSH is the precursor to melanin production and so there’s a tradeoff between production of colors through melanin and the use of the antioxidant against oxidative stress. And that may be another part of this color effect that we see in some of these organisms. Maybe there’s a threshold on melanocyte development related to that. We need to know more. I’m not much of a biochemist, so. Yes?
[ inaudible audience question ]
So, you know, good question. And we have done a couple of the microbially related studies. The first was an investigation of the microbial community on the feathers of the birds where we found, where we found that the bacterial community, it might be getting this mixed up, I have to look at the paper. I think the bacterial community was not affected by the radiation, did not change in response to the radiation. Whereas the fungal community did change depending on the background. But we also just finished a study, published a study not too long ago, let’s see if I have, I may even have a picture, yeah. We were intrigued by the fact that in parts of Chernobyl in the hotter areas and we see this in Fukushima as well, there’s an accumulation of plants, dead plant material on the ground. So these are logs from the, that were killed, trees that were killed during the initial event in 1986. Twenty years later they’re almost intact. And, you know, not a lot of microbial decomposition or insect decomposition going on. And also if you walk around where there are trees in slightly cooler areas, the litter layer is much thicker. And we have an interest in fire issues in this zone, especially with climate change. Because litter has, is where most of the radioactive contaminants are located. And we noticed that the litter area was getting thicker, was quite thick in some of these areas. So we did the experiment. Basically we went and put out our fresh clean dead plant material in little bags, you can see these little bags filled with plant material that we scattered throughout the zone, left for almost a year and then retrieved them after a year of decomposition. And low and behold decomposition rates presumably reflecting the microbial community primarily, also some invertebrates, but mostly the microbial community were dramatically effected and much lower in the hottest parts. Again we weren’t the first to notice this but we were first to do the experiment to demonstrate experimentally in this case, not just a correlation, this was an experimental manipulation that the microbial community was affected. And we’re hoping that we can get some interest by folks who specialize in metagenomic analysis of soil, microbes and maybe we can look at this question in more detail.
[ inaudible audience question ]
So the question relates to essentially, you know, we have, we’re using a very crude measure of genetic damage looking for whole chromosome breaks which are really kind of very traumatic for this [inaudible]. First is the most subtle kinds of genetic damage, you know, base pair substitution, small inversions, smaller deletions at the level of chromosomes. Where, where whole genome sequencing is required combined with the issue of the fact that large segments of the genome at least in term of the base pair sequence may not be particularly important to the expression or the survival fitness of the individual. And these are all important questions that, you know, I would love to spend more time getting to. We are initiating a couple of projects to look for, you know, look for de novo mutation rates at the level of individual base pairs. Now that we can do whole genome sequencing for not too much money, we’re starting first with human populations in collaboration with people who know how to do this. And we hope to expand that into other organisms as well. Because it’s, you know, one thing we have learned from quantitative genetics, the modern realm of quantitative genetics in the last two decades were, you know, the use of molecular markers looking for associations with disease or some other expression. One thing we have learned is that you need a lot of markers in order to find these kinds of direct associations. And we’re a long ways away for the work that we’re doing before we can find a direct linkage between a specific genetic damage, a specific event, specific site. Yeah, that’s a long ways away but, you know, that’s where we’re hoping to head. Certainly there’s interest in that.
If you don’t have any more questions, please join me to thank Professor Mousseau for the wonderful talk. Thank you.
This has been a presentation of the Library of Congress. Visit us at loc.gov.”
http://www.loc.gov/today/cyberlc/transcripts/2014/140515stb1130.txt Video: http://www.loc.gov/today/cyberlc/feature_wdesc.php?rec=6295 There are more slides at the original video. We uploaded many of them, so that people could understand the seriousness of this research. This is real, serious, academic research, unlike a study which has recently made the news, and which also misrepresented Mousseau’s work. The recent study has tainted funding tied in with the US Dept. of Energy-Savannah River Nuclear Site and a UK entity responsible for disposal nuclear waste. They obviously have a dog in the race. (Emphasis our own; A few spelling-grammar corrections of the transcript were made, especially for Dr. Steen’s introduction.)
One paper cited in Mousseau’s presentation:”Differences in effects of radiation on abundance of animals in Fukushima and Chernobyl“, by Anders Pape Møller, Isao Nishiumi , Hiroyoshi Suzuki, Keisuke Ueda, Timothy A. Mousseau (June 2012) From the Abstract: “These findings are consistent with the main effects of radiation on the abundance of animals at Fukushima being due to radiotoxicity while those at Chernobyl may be due to a mixture of radiotoxicity and mutation accumulation, because chronic exposure have been present for many generations thereby allowing for accumulation of mutations.”
From a more recent interview with Timothy Mousseau:
Even though the background radiation at Fukushima has declined somewhat over the last four years, harmful effects of the nuclear accident on birds are increasing. Mousseau states: “So now we see this really striking drop-off in numbers of birds as well as numbers of species of birds. So both the biodiversity and the abundance are showing dramatic impacts in these areas with higher radiation levels, even as the levels are declining.” http://www.sc.edu/uofsc/stories/2015/04_tim_mousseau_fukushima_birds.php. “Dwindling bird populations in Fukushima”
Posted on: 4/14/2015; Updated on: 4/15/2015 By Steven Powell