 ThinkTek Hawaii. Civil engagement lives here. Welcome to another episode of Likeable Science. I'm your host Ethan Allen here on ThinkTek Hawaii. Thanks for joining us today. Likeable Science is all about how science is a vital and interesting part of everyone's life, part of the world around us. And we should all learn about science. We should embrace it and enjoy it. We should not think of it as something confined to the ivory tower or distant laboratories. It is all around us. Today I have with me my friend Darro O'Carroll. He's back again. Darro was with me a couple of months ago. A couple of months ago. Yeah, thanks for having me back. Yeah, well it's great. He's just been up in Japan at a conference on radiation and we were talking about that. Let's talk about some radiation stuff and get a show on it. Maybe first give an overview of what you learned in this conference in Japan. Japanese conference was in Hiroshima and I think we all know the significance of that. I think what I learned it was a very short conference about four days and the field of nuclear medicine and physics is so broad that it was tough for me to learn a lot of take home points. But what I think I did take back with me is the appreciation of the Japanese culture and how they deal with disasters. Throughout the Japanese history or the history of Japan they've had so many earthquakes, so many tsunamis and back in 2013 when the tsunami hit and the earthquake hit. It was a 9.2 on the Richter scale. That's huge. That's massive. Huge tsunami. Yeah, 150 feet in some places and 18,000 people were wiped off the face of the earth. Knocked out a nuclear power plant. And then a nuclear power. So earthquake, tsunami and a nuclear fallout disaster all in one fall swoop. Like if that happened anywhere in any other country in the United States I think everybody would be pulling their hair out. And the Japanese have adapted themselves from this far in their history that they just, you know, did what they had to do. And so it's kind of they've put it into their culture and we're even like the, I think all the four local news channels came and made sure that everyone knew that all these physicians from all over the world, there were some from Mongolia, some from Brazil were coming to learn from these experts in radiation poisoning because they really are their experts. They've had some of the big cases of it. The only real use of nuclear weapons in war were of course Rosha Nagasaki. Sure. We're going to take a little different tap today though in the show and talk about it a little closer to home here and perhaps less well known less widely appreciated, which is that the 67 not just one, not just a dozen, but 67 in different nuclear tests that were done in the Marshall Islands. I was astounded when I heard that. I thought it might have been, you know, my prelim knowledge a couple or some 67 and that was just US bombs, right? Didn't the French elsewhere? I don't even know about that. They don't disclose, but somewhere in the US. Yeah, but it wasn't an arm I don't think. Those are all US. And naturally that's caused huge disruptions and their lingering health effects. Indeed, the first time I went to Majuro right across the parking lot, my hotel, there is a center that says something like US Agency for International Development, a whole body counting center and I was sort of making a back by looking at that. Do I need to go over there? What is this? And I don't realize it's part of the legacy. There are people who got massive doses of radiation who are still sort of monitoring these people. Sure. Basically. But maybe we should start out by talking a little bit about sort of what radiation is. Radiation is used as a very broad term, right? Yeah. Heat radiates out, sunlight radiates down upon us, but we're not talking about that, right? Yeah, we're talking about ionizing radiation and what we typically think of in a nuclear bomb is ionizing radiation and even X-rays that you take for over your hand, over your chest, that is a type of radiation and that is released by a nuclear bomb as well. These are radiations that can come in and literally knock atoms apart basically. Yeah. Yeah, and they can really, how they affect the human body is they do damage to mostly your DNA and they also can actually cause some severe burns as well that won't ever, you know, they take a long, long, long time to heal and sometimes they don't ever heal. Yeah. And so basically there is of course again there's sort of nuclear fission and there's nuclear fusion and fission is a splitting apart of heavy atoms and fusion is the joining of light atoms. Right. Both of those end up releasing an enormous amount of energy. Right. Nothing on Earth can ever, you know, it happens billions of times on the sun per second but this is its massive amount of energy we're talking about. Right. So we have a photo one will show the process of nuclear fission. So you take a big atom, you slam something like a neutron into it, it splits apart. Yeah. Other neutrons may go flying loose if you do that the right way. Yeah. Creates a straight chain reaction and more big atoms, but those they send off more neutrons. Yeah. And then all it took was 14 pounds of this plutonium or uranium in the fat boy and little man in Nagasaki and Hiroshima. 14 pounds of substance to release not just a thousand, how they measure the, you know, the energy released by these atoms is not by like a ton of TNT. That's how they usually use scale it. Yeah. They use a kilo ton and then this was 15 kilo tons and that's what created the bomb on Hiroshima. It's 15 kilo tons of energy. That was basically from softball size. Softball size of 14 pounds. Yeah. Of dense, heavy stuff. Yeah. And they basically surrounded that with commercial explosives. Standard commercial explosives when they're all blew up. Yeah. They call it critical mass, right? Yeah. It was more of kind of like a sleeve and baseball mechanism where it was plutonium here and then the neutron that needed to start it was shot into it like that and there it went. Yeah. Yeah. I mean, it's amazing science, but unfortunately for the wrong reason. Right. And then, so the types of nuclear radiation are shown in our, excuse me, our next picture and there are several here. So we get these alpha particles of big chunks of high basically go rather slowly or very easy to stop. Yeah. But very damaging when they do hit it. Yeah. They have a pack so much moment because they've got so much mass. They do. Yeah. So it's two protons, two neutrons and you know, a piece of paper can easily stop it. The outer layer of your skin can stop it as well. So it's not the one that kind of does a ton of external damage, but if somehow you were to ingest a Alpha source. An Alpha source. Then you know. It's going to pick out your intestines. Yeah. Yeah. So that's it's not good. And then I guess the next one from there would be beta. Right. Beta radiation and that's an electron and that can go through, you know, cutting board, piece of size, thick piece of plastic. And that's just an electron that, you know, it can penetrate for talking about human radiation now, it can penetrate that, you know, most of your outer layer of skin and into your kind of fat tissues and that sort of thing. Right. Again, more dangerous and all about really what people were much more careful about is the gamma rays. Yeah. X-rays, gamma rays. Gamma rays can penetrate through lead and that's why you need a big thick wall of concrete to be underneath or in front of you to stop these. And then the next one after that is the neutron. And the neutron, while it is a particle radiation, has enough energy to get through lead and you know, even some of concrete. So that's the one that you really need to be careful about. I mean, you may recall some a couple of decades ago that I was taught to build a neutron bomb, specifically where they would release a bunch of neutron radiation. The theory was these would be great because they would leave infrastructure intact, a relatively small explosion flooding an area with neutron radiation. Just kill off all the people, believe the buildings and then you could get your area clean. So, I mean, I don't know how we get these more good ideas. That's crazy. But somebody out there is, yeah, so all their devastating thing, as you mentioned about neutron radiation, is that it turns the environment radioactive. Right. Maybe that's what stopped them ultimately. They realized that the city looks intact, but you're not going to want to live there. Nobody will. Yeah. Because then the very walls of the buildings are re-radiating. Yep. Back at you, gamma rays, x-rays, beta. Even the soil, the trees, the plants, everything are going to... Different ones are going to produce, depending on what they hit, are going to produce different radioactive isotopes, which are going to decay at different rates. Some will decay quickly, others will last for months, others will last for years or decades or centuries, right? Even if you say I was nowhere near you to say a hundred, like a thousand miles away, you got exposed to severe neutron radiation and I took a plane and arrived half an hour after you had been exposed. You would be admitting radiation to me. Right. And probably possibly dangerous doses. Possibly fatal, if I was around you and close enough. So, neutron radiation is a deadly thing. Right. Now, neutron radiation isn't typically produced very much at all. It's by the standard fission atomic bombs, right? Correct. But when you get the hydrogen bombs, so called H bombs, we're going to infusion. Yep. Then you are getting neutron radiation. And so these thermonuclears, the technical term, but most people know them as hydrogen bombs and these are kind of the souped up, packed up, ultra-nuclear bombs. They start with a fission reaction and you need the normal, say the normal Nagasaki or Hiroshima bomb to get this going and then they compress hydrogen into deuterium, which is just two hydrogen atoms together. And then from there, it creates a massive fusion reaction. Now, instead of splitting atoms, you're joining atoms together and that releases a ton of neutrons, which accelerates the initial fission reaction. And then you just get on the order of instead of 15 kilotons, we're talking about 15,000. A thousand times bigger than Nagasaki. And so you're going from a blast radius of five kilometers. I mean, that's enough to take out any city, really, to a blast radius of not kilometers, but 40 miles. And I mean, that's like something to put it in scale. That means all of Oahu is not just radiated, it's completely incinerated. Done. Basically a fireball that big. Why did we create... We'll touch on that later. So taking this back to the Marshal, so we started doing some testing there and you can sort of see why they wanted a few. If you're going to test nasty unknown weapons, you want to do it in sort of the most remote place you can possibly do it. And here was a place stuck in the Marshall Islands, actually a fairly big country. It was right over thousands of square miles of ocean. And what we're talking about in Bikini are the far northwest corner of the Marshalls, the least inhabited part. They pulled the people off and returned those into testing grounds. They tested bombs from essentially post-World War II, I guess into the 60s maybe. I think the first thermonuclear one was 58. Yeah, so they were still doing the traditional ones. Yeah, and these make just incredible explosions. Maybe a third photo will show us Yeah, I mean you begin to get some sense of this and the next, the fourth photo actually even shows us. See this was done you can see the little palm trees and this was done probably off of it. Yeah, this was the Baker test and this was a couple seconds after it was detonated. And this is only a 20 kiloton bomb. We're not talking thermonuclear here. That was just the 20 kilotons. They had set up their older chips in the lagoon to sort of see what the impact was going to be and then the surface level blast there. And of course the worst part of this was they were also testing new bomb designs some of which turned out to be sort of duds and in a good A-bomb, everything fissions right and everything sort of broken apart. You have a huge blast of energy, radiation but then it's pretty much all gone, right? But in a dud, like an H-bomb kind of dud, you end up with like heaps of stuff left over that hasn't quite done it. It's not just that it didn't detonate, it's still radioactive, it's still Yeah, I mean it's hotter than the stuff they make nuclear fuel rods out of, right? And this stuff's now scattered across your landscape. That's what happened on both and we talking on Bikini, basically the islands were pretty much sterilized. It kind of makes you think what were we thinking? Why do you want to unleash that level of devastation? And there's all kinds of interesting sort of social aspects of that too. I mean yes, of course they did out there in Marshalls because one it wasn't in the US and two it was, it was very remote. It was as small populations as you could probably find anywhere but people did get exposed. Yeah, and I think the first thermonuclear bomb was Castle Bravo and that did a lot of damage because the US didn't think it was going to be that big. They thought it was going to be on the order of 6,000 kilotons or 6 megatons and it was performed, I guess performed is not a great word but that's what they called it. Performed better than they thought it was going to and was double the size, more than double as 15 megatons. So it was double what they thought it was going to be so that was where a lot of the problem came from. And an interesting anecdote around that too is Castle Bravo, a lot of the fallout spread all over the islands but there was a Japanese fishing vessel, the lucky fishing vessel number 24 I think it was called but they got dosed with all this fallout and so there was 24th instrument who became acutely radiation sick and back in Japan it cost huge up war because everything was very sensitive, we were talking only 12, 10, 12 years after 80,000 people were wiped out twice and it's just kind of again it makes me think, what were we thinking? Dara Carroll is with me today in the studio, I'm your host Ethan Allen, you're here with us on the show tonight so we're going to take a one minute break and then we'll be right back. Hi I'm Pete McGinnis-Mark and every Monday at one o'clock I'm the host of Think Tech Hawaii's research in Munna and at that program we bring to you a whole range of new scientific results from the university ranging from everything from exploring the solar system to looking at the earth from space, going underwater, talking about earthquakes and volcanoes and other things which have a direct relevance not only to Hawaii but also to our economy. So please try and join me one o'clock on a Monday afternoon to Think Tech Hawaii's research in Munna and see you then. Good afternoon my name is Howard Wigg I am the proud host of Code Green a program on Think Tech Hawaii we show at 3 o'clock in the afternoon every other Monday. My guests are specialists both from here and the mainland on energy efficiency which means you do more for less electricity and you're generally safer and more comfortable while you're keeping dollars in your pocket. And you're back here on likeable science I'm your host Ethan Allen here on Think Tech Hawaii with me today is Dara O'Carroll doctor who's just a radiation conference and we've been talking about radiation what it is how it's produced how it was used in the highlands. We didn't talk in the first half a little bit about the dosing how it's measured you know I mean you get a lot of radiation you get a little bit of radiation. And they use a scale called GRAYS which is Yeah it's not GRAYS anatomy but it's named after a scientist named GRAY and so GRAY is the amount of radiation that can be imparted on any object really kind of any inanimate object or human but my understanding is that the sievert is usually used in when we're talking medical purposes when it's imparted on a human but they're both the same dosage they translate one GRAY equals one millisievert to put it in perspective I mean radiation is all around us background all the time it's part from the Big Bang part from the Sun part from everything kind of going around even our bones have made a little bit of radiation and so the average dose that we are every human on the earth is subjected to in one year is two millisieverts a thousandth of a sievert so that's what we're talking about in average background presumably doing little if any real harm that's the accumulation of radiation throughout 365 days at chest x-ray it takes 40 chest x-rays to equal two millisieverts so one chest x-ray doesn't do a ton if you're getting a lot of x-rays it will add on to your accumulation dose a CT scan is about CAT scan of the chest or the abdomen is about ten millisieverts so you multiply times five your dose throughout the year so that's a significant amount and there's some fascinating studies that the Japanese are conducting in Hiroshima of they're able to see the DNA breakage just after a CAT scan and they're able to see the chromosome change if you were to put a cell if I was to get direct radiation on to part of your skin cells that are living and put that under a microscope you'd be able to see the chromosomes actually break but they get fixed but ideally so even after a CAT scan so when we're talking about radiation from nuclear fallout we're not on the millisievert dose anymore it's a full seevert it's a thousand years worth of radiation so the bomb victims in Hiroshima and Nagasaki that were unfortunately spared from the thermal incineration the ones that survived experienced anywhere from two gray to about 32 seeverts to 30 seeverts and on average there's a concept called LD50 as well and so the lethal dose of 50 so if somebody was to expose 100 people to this amount of radiation 50 of them would perish and usually they perish and we can talk about how they perish but in about a week to two weeks the LD50 so half the population would perish is about 3.5 gray 3.5 seeverts and so two seeverts is significant enough to cause it's a whopping dose to cause increased rates of if you don't pass from it you can still pass away from it but cause increased rates of cancer both solid types of cancer like liver cancer brain tumors thyroid cancer to increase rates of leukemia bone cancers all sorts of problems cataracts, liver problems, high cholesterol, high blood pressure so there's a lot of significant medical issues some lasting years and years and likely shortening your life certainly impacting the quality of your life nothing to sneeze at and really for instance the Marshallese population has certain cancers that are hundreds of times higher than sort of standard world population rates of these cancers in the studies in Japan that have shown that the increased rate of leukemia is about one and a half times the normal so you get a 50% increase of getting leukemia and that usually happens about 10 years after the radiation exposure they found the solid cancers usually happen a little bit later take a little bit more time to manifest 20 years later and they're about depending on which cancer you're talking about 5 times more likely so it's a significant if you don't pass away from it there's still a significant amount of damage that's done throughout your lifetime and the acute effects are not at all pleasant no yeah acute radiation syndrome usually affects if you're I would say the dose to really start feeling it is about one gray ish to really feel like two gray acute radiation syndrome and it usually affects the rapid turn over cells first so skin being one so you kind of and hair losing your hair but then also the really important stuff like your GI tract the intestine lining because we're always turning over the GI tract those epithelial cells then also your bone marrow and your bone marrow is responsible for hugely important like making blood you're going to get anemic you're going to be short of breath you're going to lose your white cells so you can't fight off infection and the way that most of acute radiation syndrome patients pass away from is they get really low blood counts so they have trouble breathing and also they get it's like having HIV you can't fight infections you've got sometimes no white blood cells you probably can't absorb nutrients that you need desperately to get well because your intestines are basically trashed out and you have the cells that are responsible for patching up for clots as well the platelets and so you're in the blood that you're putting in is just being usually pooped out and you're bleeding from every orifice it's really it's a really scary scary type of death. On that cheering note this is like a full science after all we should mention one of my favorite little animals of the tardigrade and we have a photo of one these are little tiny things cute little I say little they're less than a millimeter long usually so they're very very small but they're incredibly tough these animals and they you point out the LD50 on people it's about 3 gray roughly 3.5. These things the LD50 is about 5,000 gray. What are they made of? They are tough little things they've set them up and exposed them literally put them in a hard vacuum of space exposed to the vacuum of ionizing radiation of space and while that eventually knocks a bunch of them out a fair number of them that you can survive out and come back and thrive after that 50 of them you can freeze them down at like minus 20 degrees for weeks and weeks and they'll come back from that you can freeze them down to minus 200 degrees even for a few minutes. Can you go back to that photo again? Is he smiling? I can't know what their names because they are sort of cute looking they live all over the world they're not actually an extremophile that is they're not really made to live in extreme environments but they're just incredibly versatile and they can take, you can dry them out and their body goes from being 85% water down to being 3% water and then they can come back from that I mean if we go from down to probably you lose 5% of your body weight and water 10% you're in rough shape and they can lose huge amounts so they're sort of our with the radiation being the theme I just thought we had to bring them and give them a little kudos we should have a jar right here so we know if the world ever gets in bad shape they're probably going to take over and they'll become huge they'll be like a snuffle luffagus and we can all give them hugs I like it what's your take away from both the Japanese conference on radiation and now having this conversation here on the Marshall Islands you know I mean there's always I mean it kind of seems like we're going into another not to get too political another cold war type of thing tensions with Russia are always there but Hiroshima they have this flame they call it the eternal flame in the memorial park and it's going to be lit until the world is completely rid of nuclear weapons and I hope one day that flame is extinguished because what's the point I mean if why continue to have them why continue to use them why continue to even keep them in your back pocket it's all you know these big countries and you know men at the top kind of and I think for the good of humanity and they should just all be extinguished you know yeah no I agree and then you can see even the peaceful uses of nuclear radiation and power plants they're not properly designed you know Japan's going to be dealing with Fukushima for a century or more easily and nobody's really talking about it but the amount of nuclear power plants being built around the world is rapidly accelerating and most of them are being built in China and so I hope they adhere to the strict building codes yes and so I think in the next five years summer give or take there's going to be 30 nuclear power plants in China being built in the five to ten years that's a huge amount so it's a sobering thing this is a good time to sort of step back and think do we really want this stuff around if you're going to use it to care of it right yeah you know put every safeguard you can think of it my personal opinion if a nuclear power plant saves us from you know more carbon dioxide pollutants then yes let's just do it responsibly yeah absolutely yeah your responsibility is clearly awful awful thing so many levels well hey Dara thank you so much for being here it was great great to have you back here look forward to getting you all in here again okay and I hope you'll come back next week and join us in another episode of chemical science here on think tech Hawaii