[SOUND] There was no containment building. All of these fission products just blew through the roof and up into the surrounding countryside. This is a picture of what the core looked like from the air, no building in the way. Nothing to stop those debris from going. Here's another aerial picture right after the accident. Of course, this was quite a disaster, and the world noticed. Some of the first people to notice were scientists, I think in southern Germany, near Switzerland. They had some detectors set up and they said it's going to rain. Sometimes you can see the fallout from earlier atomic weapons tests and they're very sensitive detectors. And when they were looking at this experiment and the rain was coming down, they said my God, this isn't from some ten year ago nuclear experiment. This looks like the entire core contents of a nuclear reactor. A nuclear reactor in Sweden, with very sensitive radiation detection monitoring because, of course, you want to make sure nothing goes wrong in your own reactor. The alarm starts going off because of the stuff coming in the air from outside. The Soviet Union was at first very tight lipped about this. No free press, no great way to try to describe what's happening in the world. They mobilized their own fire department, of course, right in the local Chernobyl fire department, and those were the fatalities. The fire fighters wanted to put out the fire on the building, and maybe they were heroes or maybe they needed more training. Because by putting out those fires they absorbed enormous radiation doses, and over the next few days got radiation sickness, and maybe over the next few weeks perished, 30 people. The major effect on health from the Chernobyl incident was all of these fission products, these radioactive high level wastes, now shot up into the atmosphere because there was no containment building. And what's going to happen is the wind will blow and this fallout, this radioactive material, will move across the countryside. Let's watch a video that shows where the wind conditions were on those days and therefore where the radiation plumes would go with the fallout. So there is Chernobyl Power Plant in the northern part of the Ukraine. And you can see that the immediate wind pushing the fallout is right towards Sweden. In fact, it was a Swedish nuclear power plant that first even noticed that some radiation was coming out, because of course the Soviet Union was not big at publicity. Then you notice that the wind shifts back going to the east, and there was pollution all the way up to the Lapp people in Siberia. We now have wind currents pushing back down, covering Poland and more of central Europe. And you can always find Chernobyl, because it's still spewing out radioactive material, even though we're now here at May first, a few days later. The winds change, going to the south and then pushing back to the east. And one thing to note, that even though it looks like all of Europe is covered, this means there was detectable levels of cesium at one point. But it doesn't mean just because there was fallout over a certain area that the people are all going to die or the people are contaminated. The areas that have had the most coverage of red over some time will probably have quite a bit of stuff on the ground, and we'll get to that in a moment. But pretty soon here, we're at the fourth of May, fifth of May, that they did finally get the reactor all covered up. because you notice this has been a continual source and shortly here, you'll see that the source stops. Because they finally are no longer taking more material out from the reactor. Here is an actual map of the actual cesium-137, the radioactive material that is actually still measurable in the ground from the Chernobyl incident. And if we blow up the worst zones, you can see that they are here, right near the Chernobyl reactor itself, and some other places that got the immediate and the most numbers of plumes. The stuff that's in red on here is still a closed, restricted zone. A place where basically they don't let people go. The people in the next area, is a much more heavily monitored zone as well as the light pink and the yellow places sort of back to normal. Yes, you can measure the amount of cesium still in the ground, but it's deemed low enough that people can continue their normal lives in those areas. The dark red zones, particularly the town of Pripyat, right next to the Chernobyl reactor, are abandoned to this day. And they are basically empty collections of buildings because the pollution level was just too high. And you might wonder, why are we talking about cesium-137 and also iodine-131? Well the fission products from a nuclear reactor, the things that uranium splits into have a wide variety of different isotopes. And they have different half lives. Things that have half lives of millions or billions of years. Well, they don't decay. They don't give off radiation all that often, and so it's not as dangerous. The things that have a very short half life, minutes, hours, well they're extremely dangerous if you're next to them because that's what they're decaying and giving off the radiation. But they're all gone. So it's the things in the middle range the hundreds, thousand year range, that have the most potential damage. Particularly things that your body will take up. Iodine is one of those. You have iodine in your thyroid, and you need it. So if there's radioactive iodine it will go into your thyroid and then maybe give you a much higher incidence of thyroid cancer because those gamma rays coming from it will hurt your cells. Cesium can be taken up in the bone. There's not a large quick replacement of material that's in your bone. So those two isotopes are a good marker and a good thing to notice and to therefore avoid. So if we look at what are the health effects of all of this fallout, fortunately it can be measured fairly accurately. The first thing is the people who were the radiation workers, the immediate responders, the firemen. This reactor was on fire, there's large glowing chunks of the core around and the people working there rushed out to fix it. They rushed to their deaths. Of the initial 30 some fireman, they did all die, of acute radiation sickness. In all told, there were 134 people diagnosed with acute radiation sickness. This is getting something like at least 200 rems of radiation, and from that 134 people that were diagnosed with acute radiation sickness, 47 of them died. This, of course, is the immediate effect. What about the long term effect of the people that were inundated with this fallout? Well the economic effect is probably one of the largest. Because places that had the radioactive material, say the strontium or the cesium on the ground and then the cows ate it and the cows gave milk, all that milk had to be thrown away. Many of the animals had to be slaughtered and not eaten. That many of the vegetables that were growing over this time period where the material would get onto the leaves or incorporated in the plant had to be thrown away. So there was clear economic impact of the immediate fallout wash across all of this area. There are also people, particularly children, who aren't growing quickly. And in Poland and in some other places, I think they wisely administered potassium iodide. If you think about your thyroid, and it's going to pick up iodine from your diet. If you suddenly eat a whole bunch of iodine not straight iodine it's poisonous but in some forms it's not poisonous. Now the small amount of radioactive iodine you might get is very diluted so the chance of your thyroid picking it up it when you've eaten a whole potassium iodide tablet is low. And that's very helpful. Because there clearly were a large number of thyroid cancers detected in children that normally would not of course be at that rate. Fortunately 98.8% survival rate of childhood thyroid cancer is quite possible and was in this case. Of this higher incidence of thyroid cancer, which is relatively rare, but here of course in the fallout areas it was noticeably up, maybe 4,000 cases of thyroid cancer. Thyroid cancer being diagnosed and treated, it's extremely treatable, a 98.8% success rate of quote, curing or eliminating that cancer. This has led, so far, to 15 deaths. But when we not just look at immediate things, we look at long term health consequences, we wonder that, will people die sooner than they would've otherwise? There were 600,000 people. Many of these were the workers that, the army soldiers that went in to try to build the sarcophagus around the reactor. Or it was the people in those red zones that received quite a bit of fallout. This group is estimated to have had at least ten rems of radiation. Now, of this 600,000, of course, some have already died, but in any group of 600,000 people 20 to 30 years later, some amount will have died. And the key is to ask statistically how many more deaths will there be from this cohort than there would otherwise? Everyone dies, and an awful lot of people, maybe a quarter of the people who die, die of cancer. Statistically though, this is a large enough dose and a large enough number, that the estimate will be, that maybe 4,000 excess deaths will occur from this. Of course, we don't know this exactly and we can't tell which person will be an excess cancer death, but this is a fairly accepted number in this range. Now, there are clearly were millions, maybe 6 million more people, right? That all received dose, maybe on the order of one rem. And the question is, will this give us any excess deaths? The linear hypothesis which we described says, yes of course, we get ten times more they have ten times less dose that should be another four thousand people. But, the threshold hypothesis or maybe theory, says radiation dose at a low enough level is something your body has evolved with. And it's something your body can actually cure and deal with, since you're always exposed to some level of radiation. Remember, CT scan is 1.2 rem. So maybe that's three times your annual background, over this shorter time period. So will there be any excess deaths from here? Hard to quantify or tell. While this might be the science, there is very much still a psychological aspect. And since our brain and our bodies are so well linked, there are more potential medical problems. Stress disorders, my gosh, I was at Chernobyl, I was nearby, I must've received radiation. I feel sick. And probably really are, whether it had nothing to do with radiation, but it's still real. The other thing is in terminology. This group of people, the 600,000, are being monitored continuously. Because while it wasn't an intentional experiment, at least we do have an experiment in data and tracking people to look at long term health effects of radiation exposure. This group is known as The Chernobyl Victims. And just by that choice of words, it leads people to feel, that my gosh I'm going to have some health effects from this. Perhaps the term Chernobyl Survivors would have been much better. That's what you need to know about the health effects of Chernobyl. [MUSIC]
