His DNA Was Shredded By 2 Atomic Bombs. So What Happened When He Had Kids?

Post-apocalyptic genetic mutants are one of our favorite ways of scaring ourselves. But this crazy story challenges some of our basic sci-fi assumptions about what happens to human DNA when it's exposed to gamma rays. Cuz it's not like some of us haven't already lived through a nuclear bomb, right? What about two?! Yes, that really happened. Nothing stranger than real life, people. Listen in!

Mrill Ingram Curator: .

At 6:10, our hero starts a harrowing journey with a destination you won't believe. The "second nightmare" starts at 10:00, but absolutely don't miss the conclusion starting at 14:10. You will be so glad to hear it.

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Robert Krulwich: Sam are you there?
Sam Kean: I'm here. Hello.
Robert Krulwich: OK.
Jad Abumrad: Hey, Sam.
Sam Kean: Hello. How are you?
Jad Abumrad: Good. How are you?
Sam Kean: Good.
Robert Krulwich: So to begin with, we're talking to author Sam Kean.
Jad Abumrad: Radiolab regular.
Robert Krulwich: And he has just written a wonderful new book called "The Violinist's Thumb", and in it he tells a story, which is actually kind of...
Jad Abumrad: Encouraging, I think.
Robert Krulwich: Yeah.
Jad Abumrad: But to get to that part though, you have to make it through the worst luck imaginable.
Robert Krulwich: And a thousand year curse.
Jad Abumrad: Yeah.
Robert Krulwich: Well, I don't even know where to begin with you but...
Jad Abumrad: Maybe just tell us the fellow's name.
Sam Kean: The fellow's name is... hope I'm pronouncing it right. Tsutomu Yamaguchi.
Jad Abumrad: He is a Japanese of course. Story takes place in Japan, specifically...
Sam Kean: On August 6, 1945.

Robert Krulwich: What is his job? This fellow.
Sam Kean: He's a ship engineer. He designed big military and shipping boats for Mitsubishi.
Jad Abumrad: And Mr. Yamaguchi had spent the last couple of months working in Hiroshima.

Robert Krulwich: But now finally, he's about to leave.
Sam Kean: The next day.
Jad Abumrad: To return home.
Robert Krulwich: And on the morning of August 6, what's happening with him?
Sam Kean: He gets part way to work and he realizes that he has forgotten his inkan.
Robert Krulwich: What's an inkan?
Sam Kean: It's a seal that they use to stamp documents.
Robert Krulwich: Oh.
Sam Kean: That was his signature.
Jad Abumrad: Which you know was important for his work.
Sam Kean: So he goes back home to his boarding house, gets waylaid by the owners of the boarding house he's at and they say, "Would you come to have tea with us?" And he's very polite so he sits down for tea for awhile with them. Then finally, they let him go. He grabs his inkan, hops back on the bus.
Robert Krulwich: Takes his bus to street car, gets off the street car.
Sam Kean: And he starts walking. And at this point, it's about 8:15 a.m.
Jad Abumrad: He's got about a mile to walk to get to the Mitsubishi plant. So he's walking by some farms to get to the city. When all of a sudden...
Sam Kean: He hear something overhead. He looks up in the sky...
Jad Abumrad: And he sees a plane.
Robert Krulwich: Way, way up above him.
Sam Kean: And he can just see a very tiny speck descending from the belly of the plane.
Robert Krulwich: And he knows right away that's a bomb. I mean Japan is at war after all.
Sam Kean: He's been drilled in air raid tactics.
Jad Abumrad: So he drops to the ground.
Sam Kean: Covers his head and he plugs his thumbs into his ears.
Robert Krulwich: And he waits.
Sam Kean: For the big bang to go off.
Robert Krulwich: But this time, before there's even a sound.
Sam Kean: There was a very hot flash of very bright white light that sort of bathed over him. Then after that, came the roar. It actually picked him up off the ground and threw him. He could feel the air sort of racking over his belly, and it threw him down and he landed unconscious.
Jad Abumrad: OK. Before we move forward, Tsutomu's day does not end here. Let's just rewind the story, like a fraction of a second. Back to that moment when he's on the ground crouching, with his fingers in his ears and that light comes. The thing about that white light is that it is filled with...
Sam Kean: Gamma rays, which are basically like really high powered intense x-rays.
Jad Abumrad: And in that instant, light hits him. Those gamma rays shoot through his skin, into the cells of his body, where his DNA is, where they slammed into...
Sam Kean: Water molecules.
Jad Abumrad: That are clustered around the DNA.
Sam Kean: DNA is a very thirsty molecule. It has lots of water nearby it, and gamma rays...

Jad Abumrad: When they come crashing in.
Sam Kean: They knock electrons...
Jad Abumrad: Right off the water molecules.
Sam Kean: And it forms these very reactive molecules called free radicals.
Jad Abumrad: Which become like hungry little beasts.
Sam Kean: And they start to go after DNA. They are very greedy for electrons because they are missing electrons at this point. And they see this big molecule nearby, DNA, they go right after it. And they start ripping electrons off. They basically cut it at various points.
Robert Krulwich: All of which is to say that the moment the light hit him, Tsutomu Yamaguchi's DNA got shredded.
Jad Abumrad: Where did the bomb land approximately from him? Like right near him? Or was it miles and miles away?
Sam Kean: He was about a mile or so away. It's a little hard to judge but he was about a mile or so away. And he just remembers waking up, lying in the potato field.
Robert Krulwich: So then what happens?
Sam Kean: He wakes up and he has no idea how long he was unconscious because the bomb sucked up so much dirt that it sort of made the entire area dark. It was like storm clouds over the entire city, so he couldn't tell how long he been unconscious but he got to his feet and sort of started staggering through this potato field.
Robert Krulwich: And he looks down at his arms.
Sam Kean: It looked like he had this horrendous sunburn on both of his forearms, especially his left forearm, which was closer to the bomb. But he's walking by people who are torn over and bleeding or staggering. They are clearly not going to make it, and he's just sort of wandering through this field before he realizes that he should go report to work.
Robert Krulwich: He's going to go to Mitsubishi?
Sam Kean: He didn't know what to do. He was sort of dazed. That was the only thing he could think of to even try to do. It was the only real anchor he had to the city.
Robert Krulwich: But when he gets to the Mitsubishi plant, it isn't there. It's just rubble, his coworkers are dead. So he decides what he's gotta do is he's gotta find a way to get home and back to his family.

Sam Kean: And he starts hearing a rumor that there are going to be trains leaving Hiroshima to go south, which is where he's from. And he decides, he's gonna get to the train station no matter what. The unfortunate part is that he has to cross over rivers to get to the train station, and most of the bridges had been knocked out at this point.
Robert Krulwich: He finds himself walking along one river, literally filled with bodies that are beginning to pack together.
Sam Kean: And he's desperate enough, where he actually starts crawling over this bridge of bodies in the river because he had no other way of getting across, and they were clogging the river at a lot of points. So he starts crawling over them but he gets to a gap in the river, so he has to turn back. He goes a little bit downstream, and he finds that there's a railroad trestle across the river at this point. And there's one beam of it intact, so he climbs up this little tower and basically, like a tightrope walker, starts walking across this railroad trestle to get to the other side.
Robert Krulwich: Eventually he does find the train station.
Sam Kean: And there's predictably kind of a mob, waiting to get on these trains but he pushes his way through, gets to the train and he sits down.
Robert Krulwich: And the train leaves to take him home.
Sam Kean: To Nagasaki.
Jad Abumrad: Go wait. He's...
Robert Krulwich: Nagasaki.
Jad Abumrad: He's going from Hiroshima and a day later, in Nagasaki.
Sam Kean: He's going to Nagasaki the next day.
Jad Abumrad: I don't like where this is going.
Robert Krulwich: Does he find his family?
Sam Kean: He gets to them. He finds them at home.
Jad Abumrad: Spends a day swimming in and out of consciousness.
Sam Kean: And the next day, August 9, he gets up. Gets to Mitsubishi headquarters. He's bandaged up, not looking very good and he starts telling his boss and his fellow engineers about this enormous bomb that had exploded and devastated the city. And after a minute or so, his boss cuts him off and he says that this is complete baloney, "You are an engineer. Calculate it. How could one bomb destroy an entire city?" And as soon as he finish saying that, Yamaguchi felt the same flash that he felt in Hiroshima.
Jad Abumrad: Followed by that same warmth. For a second time.
Sam Kean: Yamaguchi's thought while this was happening was, oh my god, he thought the mushroom cloud had followed him from Hiroshima. In a sense, I guess he was right. It had sort of followed him there.
Jad Abumrad: And again in that flash, gamma rays flood his body.
Sam Kean: They would have created free radicals again, and it would have attacked his DNA a second time.
Jad Abumrad: A second time he pulls himself up. Staggers out of the building.
Sam Kean: That didn't collapse this time.
Jad Abumrad: And he climbs up a hill nearby.
Sam Kean: He starts looking over at Nagasaki.
Robert Krulwich: Which was burning just like Hiroshima was three days before, and the sky is black with clouds again.
Sam Kean: And he could see where his neighborhood was. And it looked like his neighborhood was completely burnt out too.
Robert Krulwich: He does eventually find his family. They made it into an air raid shelter, and they do try to restart their lives but within a short time...
Sam Kean: His health starts sinking pretty quickly. His hair fell out. He had boils erupting on his body. He kept throwing up. His face swelled. He lost hearing in one ear. His arm, he reported, looked like whale meat, that sort of bright red raw meat because he had sort of this black encrust over it. And when the second bomb came, it incinerated that and fell off.
Jad Abumrad: What was a really scary thing for scientists at that time, who you know, had begun to study the effect of radiation on the body, was that it seemed like all that physical trauma, that was just the beginning of the nightmare.
Sam Kean: Because remember these gamma rays attack the DNA that makes you, you. And that's not just a problem for you. That's the same DNA that you pass down to your kids and their kids, and their kids' kids.
Robert Krulwich: What if those genes stayed broken down through time?
Sam Kean: There was a famous quote from Hermann Muller, the person who first figured out that exposing genes to radiation could cause a lot of damage to them. He told The New York Times if the bomb survivors could foresee the results a thousand years from now, they might consider themselves more fortunate if the bomb had killed them.
Robert Krulwich: Woah.
Sam Kean: He thought that it would propagate.
Robert Krulwich: Like a biblical curse.
Sam Kean: Through the generations.
Jad Abumrad: And when the actual damage was done, how long did that take?
Sam Kean: It's over within a millisecond. The gamma rays coming in, that is over in a million of a billionth of a second. That happens pretty much instantaneously, and the free radicals doing their damage is over after about a millisecond.
Jad Abumrad: So a millisecond creates this, in Muller's, you know, forecasting, a thousand year curse?
Sam Kean: Exactly. It's over at that point.
Jad Abumrad: And here was a guy who got blasted...
Sam Kean: Twice within the span of three days.
Robert Krulwich: How many people on earth were in both blasts?
Sam Kean: There's only a handful of people that they know of who were in what they called the blast zone, about a mile or a mile and a half zone in both cites. And Yamaguchi was one of those few people.
Jad Abumrad: So the question was, was Muller right? Did these bombs create some kind of genetic curse that would echo through time? How long would it last?
Robert Krulwich: For the next 40, 50 years, scientists both in Japan and in America began to track birth defects incidents of cancer in children of those who had been hit or blasted by the bomb.
Jad Abumrad: Which brings us back to Mr. Yamaguchi.
Sam Kean: A couple of years later, Yamaguchi and his wife did decide that they wanted to have children.
Jad Abumrad: So he recovers.
Sam Kean: He does recover. He goes back to work at Mitsubishi again. It's been so good to him, he had to go back there.
Jad Abumrad: I mean it's not their fault.
Sam Kean: Right.
Jad Abumrad: Anyhow.
Sam Kean: So he gets back on his feet, his health returns and in the early 1950s, he and his wife decide that they want to have some more children. Then you could imagine there was a lot of anxiety about this, kind of throughout the world, people really didn't know what was going to happen. Especially because the initial blast of radiation really hit pregnant women hard. There were a lot of birth defects. It ended up producing a lot of babies with very tiny heads, microcephaly. And they had very low I.Qs, they couldn't do anything for themselves.
Jad Abumrad: Nonetheless, Mr. Yamaguchi and his wife decide they are gonna go for it.
Sam Kean: And they do have children.
Jad Abumrad: Children, plural?
Sam Kean: Yeah, they had two daughters after that.
Jad Abumrad: Oh.
Sam Kean: And the two daughters initially are fine. They don't have any noticeable birth defects or any birth defects. But they ended up, starting in their teenage years and especially as adults, having a lot of health problems. They had a lot of immune problems, and they quite naturally blamed it on the fact that their father got exposed to the nuclear bomb twice. And their mom got exposed once. But still...
Jad Abumrad: No cancer? No birth defects?
Robert Krulwich: And roughly 60 years later?
Sam Kean: As far as I know, they are still alive.
Jad Abumrad: Now, here's the amazing thing.
Sam Kean: In Japan, generally though, there's really no evidence that the next generation of people really suffered. The children of atomic bomb survivors in Japan really didn't have a higher incidence of birth defects or cancer or anything like that.
Robert Krulwich: Now, the people who were directly exposed to radiation, obviously they had a ton of health problems.
Sam Kean: But it's somehow didn't get passed on to the next generation it seems.
Jad Abumrad: Seriously? I find that's so surprising.
Sam Kean: Yeah. I just assumed that the next generation of children would have reported a lot of health damage, a lot of birth defects and much higher rate of cancer.
Robert Krulwich: But that didn't happen.
Jad Abumrad: Why not? I mean like how could it not affect the next generation, I mean given the way that the gamma rays attack the DNA just seems like it would have to.
Sam Kean: Well, there is evidence that...(fade)
Robert Krulwich: Sam says there's a couple of things that might have happened here. First of all, if you're talking about damage getting passed down through generations, the key thing for DNA is what's going on inside your sperm and your egg cells. Those are the sex cells.
Sam Kean: That's the only DNA that gets passed to the next generation.
Jad Abumrad: And he says, "Maybe these sex cells are just hardier than we thought."
Sam Kean: And probably even more importantly, it turns out that after four billion years, DNA can do a pretty good job of repairing itself. There's one gene in particular called the P53 gene, and that's sometimes called the guardian of the genome. And it looks for DNA damage wherever it can.
Jad Abumrad: It's sort of like our guardian angel, embedded in our genes. And there's a lot of different ways that DNA can get messed up.
Sam Kean: DNA is a double helix.
Jad Abumrad: Which means it's got these two strands of chemicals.
Sam Kean: The A, C, G and T letters.
Jad Abumrad: That all fit together, sort of like a zipper so that the letters always match.
Sam Kean: A always matches with T, and C always matches with G. So if you can read one side of the DNA strand, you know what has to appear on the opposite strand.
Jad Abumrad: So when one of the two strands get damaged, this P53 gene...
Sam Kean: Yeah, sort of whistles on over these certain handyman proteins, and they come over. They'll basically cut that strand out, throw it away...
Jad Abumrad: And pop in a new one. Because you've got A and C on one side, you know you need T and G on the other.
Sam Kean: Pretty simple. It's an ingenious system. Other times, both strands get snapped and that is kind of an emergency for your body.
Jad Abumrad: When that happens, this little guardian gene...
Sam Kean: Will basically force the cell to commit suicide.
Jad Abumrad: Because it can't afford to have that cell turn cancerous.
Robert Krulwich: Now, I don't think we wanna leave the impression that you know, you can stand in a bomb blast and your children will not be affected for sure, for sure. Because I don't think we're that sure.
Sam Kean: There is evidence that people from Chernobyl for instance, did show higher signs of birth defects but there was different kinds of radiation that got into the food supply. And when radiation gets in your body, it's kind of like a bazooka at short range and it does a lot more damage to your DNA.
Jad Abumrad: Which is why in 2011, with the reactor meltdown, the Japanese government immediately quarantined all contaminated food and animals. But still, what's sort of beautiful here is that something that seems so unbelievably intricate and fragile, like a strand of DNA. That little tiny flame that would pass into the future, that that can be so surprisingly resilient. That we can be so resilient.
Robert Krulwich: What happened to Mr. Yamaguchi? What was...
Sam Kean: He actually lived all the way until 2010.
Robert Krulwich: 2010?!
Sam Kean: He lived 65 years after that.
Jad Abumrad: How old was he?
Sam Kean: He was... let me look up to make sure. He was 93 years old when he finally died.
Robert Krulwich: Oh my god...

Big thanks to Sam Kean, whose work — we like what he does a lot. And he has a new book, which has a long title. Go ahead and read it.
Jad Abumrad: It's called "The Violinist's Thumb: And Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code".
Robert Krulwich: And what he does is he just takes a look at everything that's happened since the Human Genome Project end and he asks, "What have we learned?" And that's what the book tells you what we've learned, which is a lot.
Jad Abumrad: Yeah. I am Jad.
Robert Krulwich: I am Robert.
Jad Abumrad: Thanks for listening.
Matt Snodgrass:Hey Radiolab team, this is Matt Snodgrass. I'm a Radiolab listener from Portland, Oregon. And here is my reading of the credits. Radiolab is supported, in part, by the National Science Foundation and the Alfred P. Sloan Foundation, enhancing the understanding of science and technology in the modern world. More information at Sloan at www.sloan.org. Thank you guys for this opportunity. This is awesome. Best of luck. Bye.

There may be small errors in this transcript.

This cliff-hanger installment of "RadioLab" was created with Sam Keene, who is sharing some of his findings from his new book about what we are discovering about our DNA. Thumbnail image from the National Archives, used under Creative Commons license.

Aug 06, 2014

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