WEBVTT - Ep 53 Radiation: X-Ray Marks the Spot 0:00:01.160 --> 0:00:04.560 Just a warning out there. This is a pretty gruesome 0:00:04.720 --> 0:00:08.400 first hand account, and so if you would choose not 0:00:08.440 --> 0:00:10.840 to listen to it, please fast forward a few minutes. 0:00:12.680 --> 0:00:15.320 The midsummer sun was already glaring. On the morning of 0:00:15.360 --> 0:00:19.320 August sixth, nineteen forty five. After the all clear signal 0:00:19.320 --> 0:00:22.200 following the air raid warning, everything went back to normal, 0:00:22.280 --> 0:00:25.319 with people busy doing their own business. Going on an 0:00:25.440 --> 0:00:28.040 errand to a post office in Mayuki, Bashi under the 0:00:28.040 --> 0:00:31.480 scorching sun. I could not bear the heat anymore, so 0:00:31.520 --> 0:00:34.080 I turned back home to fetch my parasol. I was 0:00:34.240 --> 0:00:36.919 just about to open the parasol at the threshold when 0:00:36.920 --> 0:00:40.000 an intense flash burst upon me. The flash was a 0:00:40.080 --> 0:00:43.440 yellowish orange color, just like the magnesium light, but hundreds 0:00:43.440 --> 0:00:46.760 of times stronger. I instinctively rushed back into the house 0:00:46.800 --> 0:00:49.000 and laid myself down on my stomach, as had been 0:00:49.040 --> 0:00:53.040 trained in evacuation drills. Stepping outside, I found the clear 0:00:53.080 --> 0:00:55.680 blue sky had turned dim as if it were at dusk. 0:00:56.440 --> 0:00:58.800 Dust in the air blocked the view across the river. 0:00:59.360 --> 0:01:03.720 The place was filled with an indescribable smell. Pulling myself together, 0:01:03.800 --> 0:01:05.360 I looked back at my house to see if my 0:01:05.400 --> 0:01:07.840 mother was all right. Her hair was a mess and 0:01:07.920 --> 0:01:11.240 standing on end. Her lips were cracked and her head bleeding. 0:01:11.640 --> 0:01:14.800 She stood there like some unearthly creature. Then I saw 0:01:14.840 --> 0:01:17.800 my younger brother staggering about with his white cotton kimono 0:01:17.920 --> 0:01:20.959 soaked with blood. Are you both all right? I asked? 0:01:21.319 --> 0:01:25.000 That's my blood. He's not hurt, replied my mother. We 0:01:25.080 --> 0:01:27.520 carried her on a stretcher to the Mutual Aid hospital, 0:01:27.560 --> 0:01:30.120 where the doctor sewed up the cuts and her lips, jaws, 0:01:30.120 --> 0:01:32.760 and shoulders, but he did not do anything for her 0:01:32.760 --> 0:01:35.240 wounded wrist, as it had already been given first aid. 0:01:35.800 --> 0:01:37.760 Because of this, it took a long time before the 0:01:37.800 --> 0:01:40.119 wound got better, and the thumb and the index finger 0:01:40.200 --> 0:01:43.679 of her right hand were left to be paralyzed. Mother 0:01:43.760 --> 0:01:48.360 passed away in January nineteen ninety five. I also remember 0:01:48.360 --> 0:01:50.640 seeing a woman lying dead at a house by the 0:01:50.720 --> 0:01:53.280 river bank, her neck stuck through with a piece of 0:01:53.320 --> 0:01:56.480 glass blown by the blast. The glass must have cut 0:01:56.480 --> 0:01:59.800 the artery. Blood was scattered around her. She had been 0:02:00.360 --> 0:02:04.000 her baby. The baby was still absorbed and sucking the breast. 0:02:04.240 --> 0:02:06.680 There was a middle school student who was severely burned 0:02:06.720 --> 0:02:08.639 above the neck except for the top of his head, 0:02:08.720 --> 0:02:11.720 which had been protected by his combat cap. He was 0:02:11.760 --> 0:02:15.720 walking barefoot, saying, please give me water. I'm hot hot. 0:02:16.280 --> 0:02:19.440 His school uniform was burned to tatters. There came a 0:02:19.520 --> 0:02:22.519 drove of people whose faces and clothes were burned black, 0:02:23.000 --> 0:02:26.800 almost naked, and burned beyond recognition. They came tottering along, 0:02:26.880 --> 0:02:29.839 dangling their arms in front of them like ghosts. Some 0:02:29.919 --> 0:02:32.880 had their work pants burned away save the elastic strings. 0:02:33.360 --> 0:02:36.320 Others had all their clothes burned except for the front part. 0:02:36.520 --> 0:02:41.280 They kept chanting, water, give me water, exposed juicely wet flesh, 0:02:41.680 --> 0:02:46.440 peeled skin hanging from their fingertips like seaweed. An unfamiliar 0:02:46.440 --> 0:02:49.200 smell was floating in the air around the Mutual Aid Hospital. 0:02:49.520 --> 0:02:53.320 Dead bodies were piled up on the roadside. Strangely enough, 0:02:53.400 --> 0:02:55.799 I never felt the dignity of life as seriously as 0:02:55.840 --> 0:02:58.920 I do now, Faced with so many deaths, had my 0:02:59.000 --> 0:03:02.040 mind stopped working after experiencing such a sudden attack by 0:03:02.080 --> 0:03:05.800 the bomb. I took my father back home from Ninoshima 0:03:05.800 --> 0:03:09.160 on August eighth. Flies swarmed around him because of the 0:03:09.200 --> 0:03:11.959 odor his festered burns, and the white ointment gave out. 0:03:12.680 --> 0:03:16.000 It took some effort to chase the pests away. On 0:03:16.040 --> 0:03:18.040 the way to the mutual Aid hospital, there was a 0:03:18.080 --> 0:03:20.960 first aid station where wounded people in a serious condition 0:03:21.000 --> 0:03:24.680 were laid on straw mats. They were delirious, begging for water. 0:03:25.080 --> 0:03:27.960 Those whose backs were burned lay on their stomachs, and 0:03:28.000 --> 0:03:30.760 those whose front was burned lay on their back. They 0:03:30.800 --> 0:03:34.639 could not even move to change the position. Their wounds 0:03:34.680 --> 0:03:38.000 and burns were covered with countless flies laying eggs. 0:03:38.080 --> 0:03:38.280 There. 0:03:38.800 --> 0:03:42.280 Those eggs hatched into maggots, and these crawled all over 0:03:42.320 --> 0:03:47.280 their bodies, causing them infernal agony. My father asked for water, 0:03:47.680 --> 0:03:49.560 knowing he would die if he drank too much. I 0:03:49.600 --> 0:03:52.160 only gave him a tiny cup of water. I did 0:03:52.160 --> 0:03:54.760 so because I wanted him to survive. I am not 0:03:54.800 --> 0:03:56.920 sure if I did the right thing, and my heart 0:03:56.960 --> 0:03:59.920 aches whenever I think of it. On the day of Japan, Sir, 0:04:00.440 --> 0:04:04.280 he mumbled, Japan lost the war. He died undramatically the 0:04:04.320 --> 0:04:08.400 next day, complaining of the cold. The damage caused by 0:04:08.400 --> 0:04:10.680 the bomb was not confined to those who were actually 0:04:10.720 --> 0:04:14.280 exposed to it. People who sustained no injuries e g. 0:04:14.440 --> 0:04:16.560 Those who went near the hypocenter to look for their 0:04:16.600 --> 0:04:20.000 children suffered a high fever and got purple spots all 0:04:20.080 --> 0:04:23.480 over their bodies, went almost mad, and died one after 0:04:23.560 --> 0:04:26.839 another during the six months following the bombing. My elder 0:04:26.839 --> 0:04:30.040 brother was suddenly stricken with leukemia and died many years 0:04:30.080 --> 0:04:33.320 after that dreadful experience, when we had almost forgotten about it. 0:04:34.000 --> 0:04:36.560 I myself suffered from diarrhea for some time at the 0:04:36.640 --> 0:04:39.599 end of August. It is not easy for me to 0:04:39.640 --> 0:04:42.919 talk about my experience as an A bomb survivor. For me, 0:04:43.200 --> 0:04:45.960 it is like airing my dirty linen in public. But 0:04:46.040 --> 0:04:48.760 here I am to talk to you because I really 0:04:48.800 --> 0:04:51.279 want all of you to remember that the piece we 0:04:51.400 --> 0:04:54.360 have today has been achieved through the sacrifice of those 0:04:54.400 --> 0:04:57.719 people who were mercilessly killed without receiving a drop of 0:04:57.800 --> 0:05:01.799 water to quench their thirst, keep a lasting, permanent peace. 0:05:02.240 --> 0:05:05.360 I want to convey the heart of Hiroshima, hoping that 0:05:05.400 --> 0:05:08.320 what I do will be like small ripples growing into 0:05:08.360 --> 0:06:00.440 big waves and into a tidal wave. Oh my god, yeah, 0:06:00.560 --> 0:06:04.640 it's I have no words. 0:06:05.160 --> 0:06:05.440 No. 0:06:06.680 --> 0:06:12.320 So that is the story of Miyoko Wantanabi, one of 0:06:12.800 --> 0:06:17.159 the Hiba Kusha, which is the survivors of the A bomb. 0:06:17.680 --> 0:06:20.920 And there are so many of these that have been 0:06:20.960 --> 0:06:24.880 collected in a big project, and I really encourage people 0:06:24.920 --> 0:06:27.600 to go seek out more of them because it is 0:06:28.120 --> 0:06:35.200 just yeah, yeah, no, they're my goodness. Yeah wow. 0:06:36.360 --> 0:06:36.800 Yeah. 0:06:37.200 --> 0:06:41.120 Hi. I'm Eron Welsh and I'm Erin Alman Updyke and 0:06:41.160 --> 0:06:43.080 this is this podcast will Kill You. 0:06:43.680 --> 0:06:46.360 And today we're talking about radiation. 0:06:47.279 --> 0:06:50.240 Yeah. It's a very very big topic. 0:06:50.360 --> 0:06:52.040 Massive topic. Absolutely. 0:06:52.560 --> 0:06:54.560 I don't know how this episode's going to turn out 0:06:54.720 --> 0:06:58.520 eron me neither. I don't know if we're going to 0:06:58.600 --> 0:07:00.920 do it justice, but we'll try. We'll try. 0:07:01.000 --> 0:07:02.720 We'll do our best. That's all we can do. 0:07:03.480 --> 0:07:07.120 Yeah. Well, we are very excited this week because you know, 0:07:07.520 --> 0:07:11.200 radiation is a very interesting topic. It's got a massive history. 0:07:11.240 --> 0:07:15.920 The biology is super fascinating. And we were fortunate enough 0:07:15.960 --> 0:07:19.840 to speak with doctor Timothy Jorgensen, who is Associate Professor 0:07:19.880 --> 0:07:22.800 of Radiation Medicine and director of the Health Physics and 0:07:22.880 --> 0:07:27.840 Radiation Protection Graduate Program at Georgetown University in DC, and 0:07:27.920 --> 0:07:31.200 he wrote the incredible book called Strange Glow, which is 0:07:31.200 --> 0:07:34.280 really great. It's really really it's like one of the 0:07:34.320 --> 0:07:37.520 best examples of science writing. Yeah, I have ever found. 0:07:37.600 --> 0:07:40.600 I love that. I agree it explains, I am, I 0:07:40.800 --> 0:07:45.120 never took the time to learn physics properly back in 0:07:45.280 --> 0:07:50.440 undergrad and so like this was a very intimidating topic 0:07:50.520 --> 0:07:53.480 for me, and I feel like in our interview he 0:07:53.640 --> 0:07:57.360 explains it so beautifully and his book is just so clear, 0:07:57.960 --> 0:08:00.760 and it's it's engaging to read. It's really really great. 0:08:00.920 --> 0:08:04.880 Highly recommend it's yeah, totally, it's really it's really great. 0:08:04.920 --> 0:08:07.560 And so we are going to bring him on to 0:08:07.720 --> 0:08:11.400 talk first about the physics of radiation and radioactivity, how 0:08:11.400 --> 0:08:14.880 it works, what the different kinds are, and then we're 0:08:14.920 --> 0:08:17.880 going to dive into the biology and then the history. 0:08:18.000 --> 0:08:20.800 So pretty much standard, but we've got bring in some 0:08:21.160 --> 0:08:25.000 outside expertise who can talk about physics much better than 0:08:25.120 --> 0:08:25.920 you or I could do. 0:08:26.240 --> 0:08:28.040 I would never be able to do it. 0:08:28.880 --> 0:08:31.840 Although I will admit that, like after this, after reading 0:08:31.840 --> 0:08:33.559 his book, I was like, oh my gosh, I wish 0:08:33.640 --> 0:08:35.480 I had taken more physics. I wish I had like 0:08:35.880 --> 0:08:39.679 studied more about this because it is so beautiful. Some 0:08:39.760 --> 0:08:43.720 of the like examples of the logic that you need 0:08:43.760 --> 0:08:47.959 to like understand. Oh you know, how was Bragg's peak measured? Whatever? Okay, 0:08:48.360 --> 0:08:53.920 getting too much into the weeds, already, but still anyway, absolutely, 0:08:54.600 --> 0:08:55.080 oh yeah. 0:08:55.520 --> 0:09:01.640 Well, well, first of all, important business before we get started. 0:09:01.760 --> 0:09:03.000 It's quarantin any time. 0:09:03.280 --> 0:09:06.360 It is quarantiny time. What are we drinking this week? 0:09:06.720 --> 0:09:09.079 We're drinking glow and Behold. 0:09:10.000 --> 0:09:13.880 Great name, great name. Shout out to Andy, thank you 0:09:14.080 --> 0:09:14.600 so much. 0:09:15.880 --> 0:09:17.280 So what's in glow and behold? 0:09:17.480 --> 0:09:22.720 Aaron? Fantastic question, Aaron Glow and Behold has gin lemon 0:09:22.840 --> 0:09:27.040 juice thedori, which gives it that lovely neon green color 0:09:27.920 --> 0:09:30.719 and egg white, so of course it's like a gin 0:09:30.800 --> 0:09:31.719 fizz kind of a thing. 0:09:32.320 --> 0:09:35.600 Fantastic. We'll post the full recipe for that quarantiny as 0:09:35.600 --> 0:09:38.200 well as our non alcoholic placey Berita, on all of 0:09:38.240 --> 0:09:42.520 our social media channels and our website. Do we have 0:09:42.559 --> 0:09:43.960 any other business? 0:09:44.320 --> 0:09:48.080 I don't think so. I think we should just dive in. 0:09:48.600 --> 0:09:52.600 All right, let's start off by learning some physics of 0:09:52.679 --> 0:09:56.280 how radiation works right after this break. 0:10:18.160 --> 0:10:20.880 My name is Tim Jorgensen, and I'm a professor of 0:10:21.040 --> 0:10:25.240 radiation medicine and biochemistry at Georgetown University School of Medicine. 0:10:25.800 --> 0:10:28.600 I've been working there for a number of years, and 0:10:29.040 --> 0:10:32.559 I have a PhD in Radiation health Sciences from the 0:10:32.640 --> 0:10:36.560 John Tompkins School of Public Health. And my background is 0:10:36.720 --> 0:10:40.880 I'm really trained as a radiation biologist, which has led 0:10:40.920 --> 0:10:44.120 me into various aspects of that, and I run a 0:10:44.120 --> 0:10:48.800 graduate program in health physics at Georgetown excellent. 0:10:49.960 --> 0:10:52.400 So could you start us off really broadly just by 0:10:52.440 --> 0:10:55.839 explaining what is radiation and how does it work? 0:10:56.480 --> 0:10:58.720 Okay, So the simplest way to think about it is 0:10:59.600 --> 0:11:03.880 it's energy on the move. Basically, it's energy moving through space, 0:11:03.960 --> 0:11:06.480 and that can be empty space or that can be 0:11:06.559 --> 0:11:09.880 solid space. It's because depending on type of radiation, it 0:11:09.920 --> 0:11:14.120 has the ability to penetrate things like X rays. It's 0:11:14.280 --> 0:11:19.679 really there's two fundamental types. There's the electromagnetic type moves 0:11:19.920 --> 0:11:23.319 as waves and we're familiar with that microwaves, radio waves, 0:11:23.840 --> 0:11:26.080 X rays, gamma rays, and things like that. But then 0:11:26.120 --> 0:11:30.240 there's another less well known type called particulate radiation that 0:11:30.360 --> 0:11:34.840 is actually little pieces of atoms, and we also have 0:11:34.880 --> 0:11:37.959 heard of those terms too, like alpha particles, beta particles, 0:11:37.960 --> 0:11:40.920 things like that. Those are the particular types of radiation. 0:11:41.000 --> 0:11:45.440 So it comes in two flavors, electromagnetic and particulate. But 0:11:46.520 --> 0:11:48.600 the ones that we're most concerned about are those that 0:11:48.640 --> 0:11:52.360 are called the ionizing radiations, so they have enough energy 0:11:52.400 --> 0:11:56.880 that they can actually damage chemicals, they can break covalent bonds, 0:11:56.920 --> 0:11:59.320 and that's what we think the mechanism for all health 0:11:59.320 --> 0:12:02.480 effects are. So we focus a lot on the electro 0:12:02.840 --> 0:12:05.800 the ionizing radiation is because those are the ones that 0:12:05.880 --> 0:12:07.800 pack a punch in terms of health effects. 0:12:08.840 --> 0:12:09.280 Gotcha. 0:12:10.840 --> 0:12:15.320 So you mentioned at the beginning that there are these 0:12:15.320 --> 0:12:19.080 different types of radiation electromagnetic particle. Could you go into 0:12:19.080 --> 0:12:22.040 a little bit more detail on what those different types 0:12:22.080 --> 0:12:25.720 are and sort of the differences between them. 0:12:26.080 --> 0:12:30.160 Sure, So let's start out with the electromagnetic radiation. So 0:12:30.760 --> 0:12:33.760 these are all essentially the same thing. There are waves 0:12:33.800 --> 0:12:38.480 of electromagnetism that are going through space, and they're all 0:12:38.520 --> 0:12:41.199 the same. The only thing that's different is their wavelength. 0:12:42.000 --> 0:12:45.679 So usually people talk about light first because that's right 0:12:45.720 --> 0:12:48.520 in the middle waves of lengths of light are around 0:12:48.920 --> 0:12:51.760 just a few hundred nanimeters. And the thing that's interesting 0:12:51.760 --> 0:12:53.440 about this is this is the only part of the 0:12:53.600 --> 0:12:58.000 entire spectrum that humans can see. When things get longer 0:12:58.040 --> 0:13:01.800 than light, then we start getting wavelengths are longer. These 0:13:01.840 --> 0:13:06.880 are weaker types of radiation, and think radio waves, think microwaves, 0:13:06.920 --> 0:13:09.760 and things like that. These are traditionally called the non 0:13:09.880 --> 0:13:13.240 ionizing radiations. So some of these are very long, like 0:13:14.120 --> 0:13:17.040 radio waves are about the length of a football field, 0:13:17.880 --> 0:13:22.200 and X rays on the opposite side, they're just like 0:13:22.360 --> 0:13:26.160 a hundredth of the width of the human hair. So 0:13:26.200 --> 0:13:29.240 that's the that's the range that we're talking about. So 0:13:29.280 --> 0:13:31.679 as we go to the shorter waves lengths, the energy 0:13:31.760 --> 0:13:34.520 keeps going up and up and up. First we hit 0:13:34.559 --> 0:13:37.040 the X rays, and then beyond them are the gamma rays. 0:13:37.080 --> 0:13:39.520 Gamma rays are much shorter, so they have they have 0:13:39.559 --> 0:13:44.280 the highest energies, and everything would be shorter wavelengths shorter 0:13:44.320 --> 0:13:47.800 than visible light. These are called the ionizing radiations because 0:13:47.800 --> 0:13:51.920 they have enough energy to actually rip electrons off of 0:13:51.920 --> 0:13:54.840 atoms and produce ions. That's what we call them ionizing radiation. 0:13:55.240 --> 0:13:58.280 And the reason that that that's not good is because 0:13:58.320 --> 0:14:02.880 they break chemical bonds, particularly in biological molecules. So they're capable, 0:14:03.040 --> 0:14:07.040 for example, of ripping electrons off of DNA and causing 0:14:07.080 --> 0:14:10.880 breaks in DNA and other chemical reactions to happen. And 0:14:10.920 --> 0:14:13.360 so this is the mechanism of what we think all 0:14:13.400 --> 0:14:17.560 the biological consequences are. So we worry about the ionizing radiation. 0:14:17.920 --> 0:14:21.240 We don't worry so much about the non ionizing radiation. 0:14:21.800 --> 0:14:24.360 And then there are the particular radiations. So the particular 0:14:24.480 --> 0:14:30.400 radiations are released from radioactive materials. So radioactive materials are 0:14:30.920 --> 0:14:34.880 all atoms are a combination of protons and neutrons in 0:14:34.920 --> 0:14:39.120 their nucleus. The stable ones, the ones that are non radioactive, 0:14:39.160 --> 0:14:42.360 tend to have an equal number of protons and neutrons 0:14:42.360 --> 0:14:45.800 in their nucleus, but that doesn't have to be the case, 0:14:46.320 --> 0:14:51.280 and whenever there's excess protons or excess neutrons, the atom 0:14:51.400 --> 0:14:54.320 is unstable. And what it does is it does something 0:14:54.320 --> 0:14:57.400 we call decay, and that means that either a proton 0:14:57.560 --> 0:15:00.760 becomes a neutron or a neutron becomes proton, and when 0:15:00.800 --> 0:15:05.320 that happens, energy is released. Now, the energy can be 0:15:05.400 --> 0:15:10.720 released in the form of gamma rays, which are the electromagnetegration, 0:15:11.320 --> 0:15:16.240 and or it can also release particles, and so those particles, 0:15:16.960 --> 0:15:19.960 the most common ones are something called the beta particle okay, 0:15:20.000 --> 0:15:23.320 which is a negative particle equal in size and mass 0:15:23.360 --> 0:15:26.480 to an electron in net but except that it comes 0:15:26.480 --> 0:15:29.600 out of the nucleus. That's a beta particle larger particles 0:15:29.680 --> 0:15:32.760 are alpha particles. An alpha particle is really really like 0:15:32.800 --> 0:15:37.080 a helium nucleus without the electrons on it. Alpha particles 0:15:37.080 --> 0:15:39.960 on beta particles are the classic examples. There are other 0:15:40.080 --> 0:15:43.080 examples of things that are emitted fission products and things 0:15:43.160 --> 0:15:45.320 like that, but those are the main ones. And these 0:15:45.360 --> 0:15:48.840 particles also because they're charged and they have high energy, 0:15:48.880 --> 0:15:52.120 they move through materials and ionize things along the way, 0:15:52.520 --> 0:15:56.320 and so that's why we call them ionizing radiations as well. 0:15:56.480 --> 0:15:59.880 And we believe for the most part, they act on materials, 0:16:00.080 --> 0:16:03.920 biological materials in the same way they rip electrons off 0:16:04.040 --> 0:16:08.880 cause damage to chemicals, particularly biological chemicals, and that's the 0:16:08.920 --> 0:16:10.000 mechanism of their action. 0:16:10.760 --> 0:16:14.400 Gotcha. Can you talk a bit about why there's no 0:16:15.040 --> 0:16:19.800 safe level quote unquote for radiation exposure because of the 0:16:19.880 --> 0:16:21.000 cellular damage. 0:16:21.480 --> 0:16:25.160 Okay, So the key in terms of safety is that 0:16:25.280 --> 0:16:29.000 everything is related to dose. And so what we mean 0:16:29.080 --> 0:16:32.520 by dose is the amount of energy that's deposited in 0:16:32.560 --> 0:16:37.040 the material. And so the more energy you deposit in something, 0:16:37.600 --> 0:16:40.000 the more likely you are to damage it. So you 0:16:40.040 --> 0:16:43.760 can have relatively high doses. At very high doses, the 0:16:43.840 --> 0:16:47.520 damage is so severe that it will actually kill a cell, 0:16:47.920 --> 0:16:49.880 and the way that it kills a cell is by 0:16:49.960 --> 0:16:53.280 damaging the DNA. So the DNA is the critical target 0:16:53.320 --> 0:16:56.240 and the reason we keep saying DNA DNA. Everything else 0:16:56.600 --> 0:16:59.400 in the cell can be replaced, All the proteins can 0:16:59.480 --> 0:17:03.200 be replaced, all the RNA's carbohydrates, everything can be fixed 0:17:03.200 --> 0:17:07.119 and replaced. But there's only one set of DNA and 0:17:07.200 --> 0:17:10.359 each gene only has two copies. If you cause a 0:17:10.359 --> 0:17:13.359 lot of damage to the DNA, the DNA can repair 0:17:13.480 --> 0:17:16.960 some of that damage, but it can't repair a lot 0:17:17.000 --> 0:17:19.640 of damage, and so the cell will die. So these 0:17:19.680 --> 0:17:23.199 are consequences when the dose is a relatively high and 0:17:23.240 --> 0:17:28.240 that's what causes radiation syndromes, radiation sickness, and things like that. 0:17:28.600 --> 0:17:32.679 But when you get to doses below which you cannot 0:17:32.760 --> 0:17:38.240 kill cells, then essentially you don't have any of those effects, 0:17:38.520 --> 0:17:41.960 and what you really have now is an increase risk 0:17:42.160 --> 0:17:47.600 of mutagenesis. Now, most of the time this grambling or 0:17:47.720 --> 0:17:54.439 mutation is of little consequence. Let's, for example, suppose you 0:17:54.600 --> 0:17:59.320 have a liver cell and the radiation damages the hemoglobe 0:17:59.359 --> 0:18:03.120 and gene liver cell. Well, liver cells don't produce hemoglobin. 0:18:03.280 --> 0:18:06.920 They don't really care that their chemoglobal is damage. They 0:18:07.000 --> 0:18:08.320 just keep going on. 0:18:08.800 --> 0:18:09.240 But if you. 0:18:09.240 --> 0:18:13.639 Should get a mutation in the gene that regulates growth, 0:18:15.119 --> 0:18:18.320 then you can have a problem. Because growth regulation is 0:18:18.359 --> 0:18:21.080 what's keeping us from having a cancer. So if the 0:18:21.119 --> 0:18:24.840 cell loses its ability control its growth, it starts to 0:18:24.840 --> 0:18:28.200 proliferate and then you have a cancer. So we say 0:18:28.240 --> 0:18:33.680 that there is risk involved at every dose. That's rather controversial, 0:18:33.800 --> 0:18:37.000 and the reason it's controversial is there are some scientists 0:18:37.080 --> 0:18:39.520 that believe that that's not true. And the reason they don't 0:18:39.520 --> 0:18:42.840 think it's true is because we know that cells can 0:18:43.000 --> 0:18:46.600 repair low levels of damage, but these levels are so 0:18:46.840 --> 0:18:49.919 low that we cannot measure the amount of damage and 0:18:50.000 --> 0:18:52.720 repair at those levels. So that may be true, It 0:18:52.760 --> 0:18:57.320 could very well be true, but conservative assumptions are that 0:18:57.520 --> 0:19:00.960 some damage happens at every level because we cannot rule 0:19:01.000 --> 0:19:01.400 it out. 0:19:02.600 --> 0:19:06.439 Gotcha, So kind of switching gears a little bit and 0:19:06.520 --> 0:19:09.800 talking about radiation not as much of something that will 0:19:09.800 --> 0:19:12.400 give you cancer, but something that is used to treat cancer. 0:19:12.520 --> 0:19:16.480 We've come a long way in terms of the specificity 0:19:16.680 --> 0:19:20.120 and how accurately you can target certain tumors and so on. 0:19:20.240 --> 0:19:22.200 But you know, can you talk a little bit about 0:19:22.240 --> 0:19:25.320 how that works maybe in some of the risks associated. 0:19:25.880 --> 0:19:30.520 Yeah, So the actual the initial thought with radiation therapy 0:19:31.359 --> 0:19:34.959 is that it would be an ideal agent for treating 0:19:35.000 --> 0:19:40.320 cancer because it exploits that sensitivity of rapidly dividing cells. 0:19:40.840 --> 0:19:44.679 So when you have a tumor embedded within a normal tissue, 0:19:45.040 --> 0:19:49.080 the tumor is dividing more rapidly than the normal tissue is. 0:19:49.560 --> 0:19:52.160 So if you hit it with radiation, it's the tumor 0:19:52.440 --> 0:19:56.760 that will be preferentially killed by the radiation radiation, and 0:19:56.800 --> 0:20:01.600 that is the underlying basis for radiation therapy. So it's 0:20:01.600 --> 0:20:07.560 also given infractionated doses because so if you've known't anyone 0:20:07.600 --> 0:20:10.160 who's had radios and therapy, usually they come back every 0:20:10.240 --> 0:20:12.840 day for a period of time and they spread the 0:20:12.880 --> 0:20:16.640 dose over several weeks. And the reason for that is 0:20:16.640 --> 0:20:21.159 is that the normal cells repair better than the tumor cells. 0:20:21.520 --> 0:20:26.240 So by giving a rest between doses, the normal cells 0:20:26.240 --> 0:20:29.600 can exploit that rest and repair themselves better than the 0:20:29.600 --> 0:20:32.439 tumor cells can. So you have another differential, So you 0:20:32.480 --> 0:20:35.840 have two differentials. You have capitally dividing cells and the 0:20:35.840 --> 0:20:40.200 better ability of the normal tissue to repair itself compared 0:20:40.200 --> 0:20:42.680 to the tumor, and for that reason, it's a very 0:20:42.720 --> 0:20:45.360 effective treatment for cancers. 0:20:46.640 --> 0:20:49.840 I think a lot of people also don't necessarily realize 0:20:49.880 --> 0:20:53.360 that we're exposed to a certain level of background radiation 0:20:54.359 --> 0:20:57.119 all the time just by living. Can you talk a 0:20:57.119 --> 0:21:00.719 little bit about what that is and where it comes from? 0:21:00.960 --> 0:21:05.960 Yes, so we had We receive background radiation from a 0:21:06.080 --> 0:21:10.320 number of sources, both external and external to our bodies. Okay, 0:21:11.080 --> 0:21:14.040 a lot of natural chemicals that we have in our 0:21:14.080 --> 0:21:16.800 body have atoms that are radioactive, and some of the 0:21:16.800 --> 0:21:21.520 most famous ones that we hear are about potassium. And 0:21:21.560 --> 0:21:25.439 potassium is a major part of the electrolytes in our body, 0:21:25.880 --> 0:21:31.480 and potassium forty component of that potassium is radioactive. There's 0:21:31.480 --> 0:21:34.840 a lot of potassium bananas, So if you eat a 0:21:34.840 --> 0:21:38.199 banana and you have excess potassium, you pee out the 0:21:38.240 --> 0:21:41.440 same amount of potassium that you just ate. So there's 0:21:41.440 --> 0:21:45.160 the radioactivity that's in your body. I believe that your 0:21:45.359 --> 0:21:49.600 internal normal radioactivity contributes just a couple of percentage points 0:21:49.600 --> 0:21:53.080 to your total annual background does. But then there are 0:21:53.840 --> 0:21:56.879 external sources of exposure, and a lot of that comes 0:21:56.880 --> 0:22:01.399 from the ground, for example, your uranium and radium in 0:22:01.440 --> 0:22:04.399 the ground. That varies tremendously about where you are in 0:22:04.440 --> 0:22:07.080 the country, but you get some of that. So people 0:22:07.080 --> 0:22:10.640 who live in in brick buildings or mortar buildings, they 0:22:10.680 --> 0:22:13.520 get some more radiation exposure, and people who live in 0:22:13.560 --> 0:22:17.600 wooden buildings we get a lot from cosmic radiation. So 0:22:17.680 --> 0:22:20.560 cosmic radiation is radiation it's coming from the from the 0:22:20.560 --> 0:22:23.040 Sun and out other areas of the solar system and 0:22:23.119 --> 0:22:26.639 pinging on Earth. And then we have exposure from raydon. 0:22:27.000 --> 0:22:30.200 Raydon is a major source of exposure for those people 0:22:30.200 --> 0:22:33.399 who have radon in their homes largely, but it's it 0:22:33.440 --> 0:22:35.600 acts more like a spring, so you know how a 0:22:35.640 --> 0:22:37.840 spring will pop up here and not be there. So 0:22:38.000 --> 0:22:40.399 you could put one house on top of a Raydon 0:22:40.720 --> 0:22:44.080 spring and the next the neighbor have nothing. But anyway, 0:22:44.160 --> 0:22:47.160 raydon is a concern because you can breathe it and 0:22:47.240 --> 0:22:50.359 it can produce It can irradiate your lung, and it 0:22:50.400 --> 0:22:52.720 can produce lung cancer. It doesn't do anything else other 0:22:52.760 --> 0:22:56.520 than produce lung cancer. Those are the major sources. But 0:22:56.560 --> 0:22:59.640 then apart from those things, we also have to consider 0:22:59.760 --> 0:23:04.800 the average number of diagnostic and therapeutic radiation procedures that 0:23:04.840 --> 0:23:08.120 people have, and so now that's amounting to I think 0:23:08.160 --> 0:23:11.280 about a third of the total background those that people 0:23:11.280 --> 0:23:14.480 are getting annually. But again that's spotty because one person 0:23:14.520 --> 0:23:17.160 may have a lot of procedures and then the other 0:23:17.280 --> 0:23:21.600 person may have none. So anyway, but on average, for 0:23:21.680 --> 0:23:26.240 people living at sea level, they get about three milliseiverts 0:23:26.240 --> 0:23:30.439 of background radiation a year, but again it varies. So 0:23:30.560 --> 0:23:33.520 for example, people that live in Denver they get about twelve, 0:23:34.000 --> 0:23:37.080 okay milli siverts. And the reason that they're getting it 0:23:37.119 --> 0:23:40.760 is because Denver is the mile high city, right, so 0:23:40.800 --> 0:23:43.439 the air is thinner up there. They end up getting 0:23:43.480 --> 0:23:47.399 more exposure to cosmic rays and so they have a 0:23:47.480 --> 0:23:50.919 higher background level. So within the United States, the range 0:23:50.960 --> 0:23:56.760 is generally between three and twelve milliseiverts per year, but 0:23:56.800 --> 0:24:01.120 it's very heterogeneous among the population. But that's the general range. 0:24:01.920 --> 0:24:05.879 Awesome. So you kind of touched briefly earlier about this, 0:24:05.960 --> 0:24:07.680 but I was wondering if you could explain a little 0:24:07.680 --> 0:24:10.680 bit more about the differences in elements and what makes 0:24:10.720 --> 0:24:13.520 some elements radioactive and others not. 0:24:14.280 --> 0:24:19.920 Okay, so let's go back to the supernova that that 0:24:19.960 --> 0:24:22.800 created our solar system. So you can think of this 0:24:23.040 --> 0:24:27.800 as as a huge explosion like the Big Bang, and 0:24:28.400 --> 0:24:33.359 all the elemental subatomic particles, the protons and the neutrons, 0:24:33.600 --> 0:24:36.560 they all just scrambled and coalesced and came back together. 0:24:37.359 --> 0:24:40.960 The ones that came back together with five protons and 0:24:41.040 --> 0:24:46.159 fourteen neutrons, they were so unstable they disappeared instantly, and 0:24:46.200 --> 0:24:49.440