{"version":"1.0.0","segments":[{"startTime":5.555,"endTime":11.207,"body":"This year, I'm going to be doing a series of lectures on, uh, medical and"},{"startTime":11.207,"endTime":13.845,"body":"healthcare issues after disasters and major accidents."},{"startTime":14.685,"endTime":21.09,"body":"And in the first one, I'm gonna talk about reducing harms after radiological nuclear and"},{"startTime":21.09,"endTime":21.945,"body":"chemical emergencies."},{"startTime":24.125,"endTime":29.93,"body":"Now, uh, these are broadly defined, defined as, uh, radiological incidents, uh, where you don't"},{"startTime":29.93,"endTime":30.317,"body":"have a blast or explosion from a nuclear event, uh, a nuclear incident, uh, where"},{"startTime":30.317,"endTime":30.705,"body":"there is a blast or explo or exposure, uh, due to nuclear fission, uh, and"},{"startTime":30.705,"endTime":43.865,"body":"then chemical, which can be deliberate."},{"startTime":44.165,"endTime":48.425,"body":"So, chemical warfare, for example, poisonings, uh, or accidental."},{"startTime":48.445,"endTime":49.625,"body":"Now I'm in the chemicals."},{"startTime":49.645,"endTime":55.23,"body":"I'm really gonna talk, uh, just as about the, uh, agents that are used in,"},{"startTime":55.23,"endTime":57.465,"body":"uh, military, uh, uses throughout this."},{"startTime":58.165,"endTime":64.523,"body":"The key thing to understand with both radiological and, uh, with chemical issues is an"},{"startTime":64.523,"endTime":64.946,"body":"old, uh, saying from Paracelsus, uh, in the 16th century that the dose makes the"},{"startTime":64.946,"endTime":71.305,"body":"poison."},{"startTime":72.055,"endTime":77.83,"body":"Very low doses of either radiation, uh, or of even quite dangerous chemicals, uh, are"},{"startTime":77.83,"endTime":82.065,"body":"usually harmless or you recover from them, uh, really quite quickly."},{"startTime":82.565,"endTime":86.345,"body":"Uh, high doses, of course, are what cause significant problems."},{"startTime":88.545,"endTime":95.225,"body":"Radiological, uh, nuclear and chemical incidents tend to cause widespread and very understandable concern."},{"startTime":95.225,"endTime":100.701,"body":"They tend to dominate, uh, the news agenda, uh, and they are indeed, um, uh,"},{"startTime":100.701,"endTime":101.067,"body":"dramatic, uh, and, uh, are turned quite frequently into dramas, including, uh, two very, uh,"},{"startTime":101.067,"endTime":109.465,"body":"well, uh, regarded, uh, ones I've put up here."},{"startTime":110.085,"endTime":115.077,"body":"Um, this talk, however, is going to talk, uh, to think much more about the"},{"startTime":115.077,"endTime":115.41,"body":"science of these events, uh, and also what we can do in health terms to"},{"startTime":115.41,"endTime":124.065,"body":"minimize the risk to, uh, individuals, to families, uh, after the event,"},{"startTime":126.465,"endTime":133.125,"body":"Radiological incidents from civil, mainly from civil, uh, um, uh, nuclear ins, uh, installations are"},{"startTime":133.125,"endTime":139.785,"body":"the, um, the are the most common of these, although even these are very rare."},{"startTime":141.005,"endTime":145.892,"body":"Um, some important, uh, large scale events include, uh, the Fukushima and the au, uh,"},{"startTime":145.892,"endTime":148.825,"body":"disasters we shall talk about, uh, in more detail."},{"startTime":149.165,"endTime":154.824,"body":"But there have also been, uh, leaks from nuclear, uh, inst, uh, installations, uh, in"},{"startTime":154.824,"endTime":157.465,"body":"the USA three Mile Island, for example."},{"startTime":157.845,"endTime":163.095,"body":"Uh, and in the uk in Windscale mainly, uh, very, uh, small and with, uh,"},{"startTime":163.095,"endTime":164.145,"body":"limited health impacts."},{"startTime":164.205,"endTime":166.865,"body":"And there have been several smaller incidents along the way."},{"startTime":167.485,"endTime":171.907,"body":"The Gresham College lecture that you're listening to right now is giving you knowledge and"},{"startTime":171.907,"endTime":172.202,"body":"insight from one of the world's leading academic experts, making it takes a lot of"},{"startTime":172.202,"endTime":176.625,"body":"time."},{"startTime":177.125,"endTime":180.312,"body":"But because we want to encourage a love of learning, we think it's well worth"},{"startTime":180.312,"endTime":180.525,"body":"it."},{"startTime":181.505,"endTime":185.688,"body":"We never make you pay for lectures, although donations are needed, all we ask in"},{"startTime":185.688,"endTime":186.525,"body":"return is this."},{"startTime":187.035,"endTime":189.365,"body":"Send a link to this lecture to someone you think would benefit."},{"startTime":189.705,"endTime":193.388,"body":"And if you haven't already, click the follow or subscribe button from wherever you are"},{"startTime":193.388,"endTime":194.125,"body":"listening right now."},{"startTime":195.265,"endTime":197.125,"body":"Now, let's get back to the lecture."},{"startTime":199.515,"endTime":205.047,"body":"Now, it's important when thinking about this to recognize that, uh, power generation, at least"},{"startTime":205.047,"endTime":208.735,"body":"by conventional sources, has always had a risk to health."},{"startTime":209.315,"endTime":213.855,"body":"Uh, and most conventional power generation, uh, causes substantial air pollution."},{"startTime":215.075,"endTime":217.415,"body":"And this causes, uh, very significant harm."},{"startTime":217.915,"endTime":223.851,"body":"Uh, coal, uh, burning, uh, for production of power in particular, is extremely damaging to"},{"startTime":223.851,"endTime":224.247,"body":"human health, uh, and through air pollution can cause increases in heart disease, stroke, lung"},{"startTime":224.247,"endTime":224.643,"body":"cancer, uh, and, uh, many other, uh, potential diseases, uh, and nuclear, uh, power needs"},{"startTime":224.643,"endTime":238.495,"body":"to be seen, uh, in that context."},{"startTime":239.275,"endTime":243.704,"body":"Uh, I have given a talk previously at Gresham College, uh, on the risks of"},{"startTime":243.704,"endTime":244.295,"body":"air pollution."},{"startTime":245.995,"endTime":251.75,"body":"Uh, and here's a graphical way, uh, of really demonstrating this, uh, and showing that"},{"startTime":251.75,"endTime":252.134,"body":"deaths from, uh, air pollution and other accidents, uh, are much higher actually, in terms"},{"startTime":252.134,"endTime":262.495,"body":"of numbers, particularly from the most polluting form of coal, uh, called lignite."},{"startTime":262.795,"endTime":268.157,"body":"Uh, but coal in general has, uh, and to lesser extent, oil ha burning have"},{"startTime":268.157,"endTime":271.375,"body":"very significant potential health impacts due to, uh, pollution."},{"startTime":274.795,"endTime":282.076,"body":"Moving on to, um, uh, radiological incidents, accidents tend to be either due to, uh,"},{"startTime":282.076,"endTime":282.562,"body":"the human error or to natural disasters, and they can be some combination of those,"},{"startTime":282.562,"endTime":290.815,"body":"uh, to novel."},{"startTime":291.075,"endTime":297.12,"body":"In 1986 is the best known, uh, the best studied, uh, and the largest of"},{"startTime":297.12,"endTime":297.523,"body":"these, uh, the causes for it, uh, were complex, and a whole series of things"},{"startTime":297.523,"endTime":304.375,"body":"essentially lined up."},{"startTime":304.755,"endTime":309.895,"body":"Uh, combination of poor design of the reactor and human error, uh, led a test"},{"startTime":309.895,"endTime":312.295,"body":"shutdown to lead to an energy surge."},{"startTime":312.755,"endTime":314.815,"body":"And then there was a, an explosion."},{"startTime":314.925,"endTime":320.109,"body":"It's caused by steam, uh, and then a secondary explosion, which breached, uh, the, the"},{"startTime":320.109,"endTime":320.455,"body":"call."},{"startTime":321.035,"endTime":324.981,"body":"Um, and then there was a reactor fire, and that led to, uh, radioactive material"},{"startTime":324.981,"endTime":325.245,"body":"being carried, carried a long way up 'cause of the heat of the fire into"},{"startTime":325.245,"endTime":329.455,"body":"the atmosphere."},{"startTime":329.515,"endTime":334.095,"body":"And then, uh, it, uh, tracked around, uh, over Europe, uh, for quite some time."},{"startTime":335.315,"endTime":336.855,"body":"I'm not gonna go into the details of this."},{"startTime":337.025,"endTime":341.469,"body":"Those who are interested can look at the IAEA report on this, which is really"},{"startTime":341.469,"endTime":342.655,"body":"the definitive, uh, version."},{"startTime":345.185,"endTime":352.535,"body":"Fukushima, um, uh, in 2011 in Japan, uh, was, uh, largely caused by a natural,"},{"startTime":352.535,"endTime":353.515,"body":"uh, disaster."},{"startTime":354.095,"endTime":358.356,"body":"An earthquake, uh, led, uh, to the, uh, reactor shutting down as it was designed"},{"startTime":358.356,"endTime":358.925,"body":"to do."},{"startTime":359.225,"endTime":364.593,"body":"But then there was a sub, sub subsequent tsunami wave, uh, which damaged, uh, the"},{"startTime":364.593,"endTime":369.605,"body":"cooling, uh, system, and then the reactors overheated, and there was a partial meltdown."},{"startTime":370.305,"endTime":373.685,"body":"And then there were subsequent explosions, mainly due to hydrogen buildup."},{"startTime":373.685,"endTime":374.885,"body":"To be clear, this is hydrogen."},{"startTime":374.885,"endTime":377.965,"body":"The gas, this isn't a hydrogen, uh, like a hydrogen bomb."},{"startTime":377.965,"endTime":382.577,"body":"This is actually just buildup of hydrogen gas, uh, which, uh, exploded and breached the"},{"startTime":382.577,"endTime":382.885,"body":"core."},{"startTime":383.415,"endTime":386.722,"body":"Again, the, the, uh, there is an official report of this for those who are"},{"startTime":386.722,"endTime":387.605,"body":"interested in the details."},{"startTime":390.385,"endTime":395.685,"body":"Now, after there's been an accident, there are broadly four kinds of effects on health."},{"startTime":396.745,"endTime":401.558,"body":"The first of these, um, uh, the first two of these are really only going"},{"startTime":401.558,"endTime":404.125,"body":"to occur for people in the immediate vicinity."},{"startTime":404.355,"endTime":409.668,"body":"Generally, people who are actually nuclear workers or emergency workers on the site at the"},{"startTime":409.668,"endTime":411.085,"body":"time of the emergency."},{"startTime":411.875,"endTime":416.95,"body":"There's physical trauma, um, if there are explosions, and there were explosions in both those"},{"startTime":416.95,"endTime":417.965,"body":"two, uh, cases."},{"startTime":418.665,"endTime":424.17,"body":"And then there is acute radiation sickness, uh, which I'll go on to describe, uh,"},{"startTime":424.17,"endTime":424.537,"body":"in the next few slides for those not actually on the site, um, there is"},{"startTime":424.537,"endTime":432.245,"body":"a risk, uh, but it's massively lower."},{"startTime":432.825,"endTime":438.238,"body":"Uh, and the longer term, uh, effects, which can occur for people who are exposed"},{"startTime":438.238,"endTime":441.125,"body":"usually to a radioactive plume, downwind are cancers."},{"startTime":441.305,"endTime":444.525,"body":"But the rate, the rates of those as I show, are low in fact."},{"startTime":444.905,"endTime":446.405,"body":"And then psychological effects."},{"startTime":446.465,"endTime":451.995,"body":"And the studies of, uh, hun, uh, nuclear disaster survivors showed that these psychological effects"},{"startTime":451.995,"endTime":457.525,"body":"were often the most, both the most common and in many ways, the most severe."},{"startTime":457.625,"endTime":461.285,"body":"So people worry about it, uh, after the event, for understandable reasons,"},{"startTime":464.345,"endTime":470.045,"body":"To understand the risks, um, and how to, uh, reduce them significantly after an event."},{"startTime":470.555,"endTime":474.445,"body":"It's important that we have, uh, a basic understanding of radiation."},{"startTime":474.865,"endTime":479.586,"body":"So the next few slides are really going to just run through some key bits"},{"startTime":479.586,"endTime":480.845,"body":"of understanding of radiation."},{"startTime":482.015,"endTime":489.233,"body":"There are broadly three types of, uh, radioactive material or radioactive exposure, uh, which are"},{"startTime":489.233,"endTime":494.045,"body":"important after a radiological, uh, and indeed a nuclear incident."},{"startTime":494.145,"endTime":499.431,"body":"Uh, alpha particles, um, these are, are, these can travel just a few centimeters in"},{"startTime":499.431,"endTime":504.365,"body":"air, uh, and they can be stopped by a variety of relatively small barriers."},{"startTime":505.635,"endTime":507.605,"body":"Then there are beta particles more important."},{"startTime":508.105,"endTime":513.405,"body":"Um, and these can travel tens of centimeters in the air, but not huge distances."},{"startTime":513.784,"endTime":516.605,"body":"Uh, and again, they can be stopped by slightly larger barriers."},{"startTime":516.705,"endTime":519.284,"body":"And then finally, um, there are gamma rays."},{"startTime":519.284,"endTime":520.565,"body":"These are not particles."},{"startTime":520.565,"endTime":526.365,"body":"These are, uh, wave forms, uh, and they can travel many meters to some kilometers,"},{"startTime":526.365,"endTime":527.525,"body":"but not indefinitely."},{"startTime":527.785,"endTime":531.885,"body":"But the further they travel, the more their energy will be attenuated, reduced."},{"startTime":532.185,"endTime":535.565,"body":"Um, so, uh, the effects will weaken over distance."},{"startTime":539.125,"endTime":544.825,"body":"And just, you know, to reiterate this point, alpha particles are stopped by things as"},{"startTime":544.825,"endTime":545.205,"body":"as limited as paper, uh, and the out outer, therefore dead, uh, layer of the"},{"startTime":545.205,"endTime":550.905,"body":"skin."},{"startTime":551.965,"endTime":556.812,"body":"So really, if it's only if, uh, significant amounts are ingested, they tend to cause,"},{"startTime":556.812,"endTime":558.105,"body":"uh, any significant harm."},{"startTime":558.895,"endTime":564.757,"body":"Beta particles, uh, again, more important, uh, are stopped by glass, aluminum and other relatively"},{"startTime":564.757,"endTime":568.665,"body":"small, uh, barriers, uh, or at least very significantly reduced."},{"startTime":570.205,"endTime":576.625,"body":"And gamma rays can penetrate those, uh, but they are significantly attenuated by, uh, walls,"},{"startTime":576.625,"endTime":580.905,"body":"uh, uh, and brick made of brick, concrete or stone."},{"startTime":581.245,"endTime":585.233,"body":"And essentially, the larger, the mass between you and the gamma ray source, the lower"},{"startTime":585.233,"endTime":588.425,"body":"the amount, the dose of radiation that you are going to get."},{"startTime":589.015,"endTime":591.305,"body":"Repeating my constant refrain through this talk."},{"startTime":591.605,"endTime":593.065,"body":"The dose equals the poison."},{"startTime":593.125,"endTime":596.818,"body":"If you can reduce the po the dose, then uh, the effects will be much"},{"startTime":596.818,"endTime":597.065,"body":"smaller."},{"startTime":601.155,"endTime":607.167,"body":"The human body, uh, is remarkable in its ability to handle and to recover from"},{"startTime":607.167,"endTime":610.775,"body":"large numbers, uh, of, uh, uh, assaults on it."},{"startTime":611.155,"endTime":613.015,"body":"And radiation is one of these."},{"startTime":614.265,"endTime":620.304,"body":"Radiation is actually occurring in the background every day as radiation in, in, uh, almost,"},{"startTime":620.304,"endTime":621.915,"body":"uh, all, uh, environments."},{"startTime":622.455,"endTime":627.035,"body":"Um, some buildings are, have, have higher levels of radiation."},{"startTime":627.325,"endTime":632.155,"body":"Quite a lot of very healthy foods, uh, have traces of radiation."},{"startTime":632.155,"endTime":637.235,"body":"Tobacco has radiation, um, and so you are being exposed to radiation the whole time."},{"startTime":637.375,"endTime":642.025,"body":"Now, come on in a second to kind of the doses we're talking about at"},{"startTime":642.025,"endTime":642.955,"body":"a higher dose."},{"startTime":643.415,"endTime":647.995,"body":"Um, uh, in medicine, we use radiation in two, broadly, two ways."},{"startTime":648.695,"endTime":651.715,"body":"Uh, it's used diagnostically using X-rays."},{"startTime":651.715,"endTime":656.735,"body":"And people who have an X-ray have a CT scan are exposed to very small"},{"startTime":656.735,"endTime":657.069,"body":"amounts of radiation, which really have, uh, for practical purposes, uh, with the exception of"},{"startTime":657.069,"endTime":657.404,"body":"fetuses, um, uh, from, for women who are pregnant, but for practical purposes, have, uh,"},{"startTime":657.404,"endTime":671.795,"body":"no increase in risk, uh, under ordinary circumstances if people just have a single x-ray."},{"startTime":672.135,"endTime":678.079,"body":"Uh, and then the, at a much, much higher dose, uh, radiotherapy, which is based"},{"startTime":678.079,"endTime":678.476,"body":"on the fact that, uh, healthy cells exposed to radiation may be damaged, but they"},{"startTime":678.476,"endTime":687.195,"body":"will then recover, uh, from the radiation dose."},{"startTime":687.535,"endTime":692.315,"body":"So the body can both handle small amounts and recover from, uh, larger amounts."},{"startTime":693.615,"endTime":698.065,"body":"Now, I talked about cancer treatment in a, uh, a series, uh, a previous series"},{"startTime":698.065,"endTime":698.955,"body":"at Gresham Cottage."},{"startTime":699.095,"endTime":703.282,"body":"I'm not gonna go through this in detail, but I think it's just useful to"},{"startTime":703.282,"endTime":705.795,"body":"understand this background for understanding the, uh, wider risk."},{"startTime":706.335,"endTime":711.682,"body":"So the way in which, uh, radiotherapy occurs, uh, in a variety of ways of"},{"startTime":711.682,"endTime":712.395,"body":"achieving it."},{"startTime":712.495,"endTime":717.246,"body":"But, um, the most common thing is to, uh, fire external radiation at the body"},{"startTime":717.246,"endTime":717.563,"body":"from, uh, multiple angles so that there's only one, only the area with a cancer"},{"startTime":717.563,"endTime":725.165,"body":"in it has a very, very high level of radiation."},{"startTime":725.505,"endTime":730.09,"body":"The other areas of the body that the radiation passes through has a much lower"},{"startTime":730.09,"endTime":731.925,"body":"level, and those cells will recover."},{"startTime":731.985,"endTime":736.863,"body":"So again, this is just a demonstration of the fact that normal cells will recover"},{"startTime":736.863,"endTime":737.189,"body":"from radiation, uh, in the great majority of cases, and the right of ways of"},{"startTime":737.189,"endTime":737.514,"body":"doing it on the right, I've shown, uh, how, um, uh, both, uh, x-ray type"},{"startTime":737.514,"endTime":750.525,"body":"and proton beam therapies can be used for this concentration of x-rays."},{"startTime":750.815,"endTime":757.853,"body":"Where a, uh, cancer is found, there are quite, there are the way in which"},{"startTime":757.853,"endTime":763.015,"body":"you measure the, uh, amount of radiation can get quite confusing."},{"startTime":763.155,"endTime":766.055,"body":"Uh, gray's, seaberts, a variety of ways of, of thinking about it."},{"startTime":766.475,"endTime":771.156,"body":"Uh, one way that people have thought about it is the, uh, number of, um,"},{"startTime":771.156,"endTime":771.468,"body":"bananas you'd need, uh, to eat to achieve the same amount of radiation exposure, because"},{"startTime":771.468,"endTime":771.78,"body":"even bananas, very healthy, uh, uh, food, like many other foods, have a very small,"},{"startTime":771.78,"endTime":783.015,"body":"very small amount of, uh, radiation in them."},{"startTime":783.515,"endTime":788.756,"body":"And on the left here, uh, you can see, um, uh, the, and essentially the"},{"startTime":788.756,"endTime":789.455,"body":"banana equivalent."},{"startTime":789.455,"endTime":793.547,"body":"This is a slightly crude scale, so, but it's just to give a sort of"},{"startTime":793.547,"endTime":797.095,"body":"sense of relative scale, uh, of, um, the amount of radiation you get."},{"startTime":797.095,"endTime":800.495,"body":"So your normal background dose would be around about a hundred."},{"startTime":800.735,"endTime":803.415,"body":"A dental X-ray would be lower than that, so it's less than a day's worth."},{"startTime":803.915,"endTime":809.367,"body":"Uh, a, an X-ray of the chest, uh, might be somewhere between twice and five"},{"startTime":809.367,"endTime":810.095,"body":"times that."},{"startTime":810.195,"endTime":812.695,"body":"So five days worth of background radiation."},{"startTime":813.155,"endTime":817.802,"body":"Uh, and, and the, the, by, by the time, by the time, you know, by"},{"startTime":817.802,"endTime":818.111,"body":"the time you get up to ct, slightly higher than that, but really a, a"},{"startTime":818.111,"endTime":818.421,"body":"very substantially greater amount of radiation for radiotherapy, um, and a massively higher dose, uh,"},{"startTime":818.421,"endTime":829.575,"body":"if you are to have a fatal dose."},{"startTime":829.575,"endTime":834.275,"body":"These are the kinds of, uh, levels of radiation, which actually are going to cause"},{"startTime":834.275,"endTime":835.215,"body":"really substantial harm."},{"startTime":837.365,"endTime":840.425,"body":"So, low doses we handle, uh, as bodies, uh, really well."},{"startTime":843.895,"endTime":849.816,"body":"So the first of the major causes of, uh, illness after exposure to radiation, um,"},{"startTime":849.816,"endTime":851.395,"body":"is acute radiation sickness."},{"startTime":851.505,"endTime":855.855,"body":"This is by far the most severe end of the spectrum, uh, and a relatively"},{"startTime":855.855,"endTime":858.755,"body":"or very small number of people, uh, will be affected."},{"startTime":858.895,"endTime":863.263,"body":"But for them, uh, this, uh, is a serious, uh, risk to their health for"},{"startTime":863.263,"endTime":863.555,"body":"this."},{"startTime":863.735,"endTime":867.391,"body":"And these, as I say, will be people really just on the site of an"},{"startTime":867.391,"endTime":867.635,"body":"emergency."},{"startTime":867.635,"endTime":872.995,"body":"Generally, there are four, uh, sub syndromes with right of ways of describing this."},{"startTime":873.375,"endTime":878.186,"body":"Uh, but they, they're all, uh, caused by the fact that radiation has its biggest"},{"startTime":878.186,"endTime":881.715,"body":"impact on the cells in the body that are rapidly dividing."},{"startTime":882.665,"endTime":888.521,"body":"Uh, and the, for the hemopoietic system, this is the thing that makes blood, uh,"},{"startTime":888.521,"endTime":891.645,"body":"makes red cells, makes platelets, which stop bleeding."},{"startTime":892.105,"endTime":896.085,"body":"Uh, and importantly, it makes white cells which fight infection."},{"startTime":896.785,"endTime":900.887,"body":"And if the bone marrow is temporarily essentially switched off because of the damage from"},{"startTime":900.887,"endTime":901.161,"body":"the radiation as it recovers, uh, you can have a period of time when people"},{"startTime":901.161,"endTime":906.085,"body":"have anemia, uh, there."},{"startTime":906.225,"endTime":912.093,"body":"Uh, but more importantly, uh, they are very susceptible to infection until their white cells"},{"startTime":912.093,"endTime":912.485,"body":"recover."},{"startTime":913.555,"endTime":915.525,"body":"Then there's, uh, the gastro tonal system."},{"startTime":915.745,"endTime":920.565,"body":"The gut, gut rapidly, uh, turns over, uh, with diarrhea and a variety of other,"},{"startTime":920.565,"endTime":920.886,"body":"uh, gut problems, uh, the cutaneous system, the skin system, including, uh, hair, uh, and"},{"startTime":920.886,"endTime":930.205,"body":"then the neurovascular system, which really only tends to be affected by very high doses."},{"startTime":930.385,"endTime":936.285,"body":"Indeed, all of these, uh, are in the great majority of people temporary, so they"},{"startTime":936.285,"endTime":936.678,"body":"will recover, but, um, for a period, they will be at significant risk because of,"},{"startTime":936.678,"endTime":943.365,"body":"uh, radiation sickness."},{"startTime":945.545,"endTime":949.49,"body":"And for those who get radiation sickness, there are four stages, and not everybody, uh,"},{"startTime":949.49,"endTime":950.805,"body":"goes through all of them."},{"startTime":951.865,"endTime":956.479,"body":"The first of them, which happens commonly, including people who actually go on to have"},{"startTime":956.479,"endTime":958.325,"body":"no further issues, is a prodrome."},{"startTime":958.325,"endTime":959.885,"body":"People feel really very rapidly."},{"startTime":960.315,"endTime":965.691,"body":"They have vomiting or a nausea, headaches, loss of appetite, diarrhea, fever, and this is"},{"startTime":965.691,"endTime":967.125,"body":"a short term effect."},{"startTime":967.505,"endTime":969.485,"body":"Uh, and it then, uh, improves."},{"startTime":970.835,"endTime":973.125,"body":"Then there's a period for days, uh, to weeks."},{"startTime":973.265,"endTime":977.18,"body":"Um, the shorter the, uh, those, the bigger the dose, the shorter the period where"},{"startTime":977.18,"endTime":978.485,"body":"people make an apparent recovery."},{"startTime":978.715,"endTime":982.456,"body":"They, in more severe cases, they may have some hair loss, but otherwise they appear"},{"startTime":982.456,"endTime":983.205,"body":"to get better."},{"startTime":983.825,"endTime":989.532,"body":"And then weeks to months later, uh, there is a period of illness, manifest illness"},{"startTime":989.532,"endTime":989.913,"body":"where people have diarrhea, infection, anemia, um, uh, and during this period, they are very"},{"startTime":989.913,"endTime":998.285,"body":"vulnerable, particularly, as I say, to, uh, infections."},{"startTime":999.105,"endTime":1005.053,"body":"And then, except in people who have the heaviest dose, there will be recovery and"},{"startTime":1005.053,"endTime":1005.45,"body":"people will recover, uh, largely or completely from their radiation dose to give some sense"},{"startTime":1005.45,"endTime":1011.795,"body":"of scale."},{"startTime":1012.355,"endTime":1019.096,"body":"Remembering that, uh, VO was the, uh, largest, um, civil nuclear, uh, sorry, civil, civil"},{"startTime":1019.096,"endTime":1019.995,"body":"radiological event."},{"startTime":1020.535,"endTime":1027.918,"body":"Um, uh, that, that had probably about 134 acute radiation sickness in total, uh, and"},{"startTime":1027.918,"endTime":1029.395,"body":"around 28 deaths."},{"startTime":1029.895,"endTime":1035.993,"body":"Uh, Fukushima, uh, had no, um, deaths from acute radiation sickness recorded at all."},{"startTime":1036.095,"endTime":1039.755,"body":"So these are rare, but these are obviously serious when they occur."},{"startTime":1042.454,"endTime":1045.473,"body":"And what will happen depends on the dose."},{"startTime":1046.535,"endTime":1052.298,"body":"So, uh, at a relatively low dose, um, this is, uh, uh, measured in grays"},{"startTime":1052.298,"endTime":1053.835,"body":"on this particular thing."},{"startTime":1053.835,"endTime":1055.995,"body":"These, these da these data are, again, open source."},{"startTime":1056.615,"endTime":1062.094,"body":"Uh, people will have the prodrome, they may have the nausea, vomiting, and anemia, and"},{"startTime":1062.094,"endTime":1062.459,"body":"they may, uh, subsequently have a slightly increased risk of infection and of fever, but"},{"startTime":1062.459,"endTime":1069.765,"body":"the recovery will be relatively quick."},{"startTime":1070.225,"endTime":1075.412,"body":"Uh, there isn't severe disease, and there will be no mortality, uh, in people who've"},{"startTime":1075.412,"endTime":1078.525,"body":"had this kind of very low dose, uh, overall,"},{"startTime":1080.845,"endTime":1085.905,"body":"Uh, at a high, uh, dose, but not a completely lethal dose for most people."},{"startTime":1086.325,"endTime":1091.653,"body":"Here's, um, a, uh, someone who's been exposed to, uh, three to five grays, uh,"},{"startTime":1091.653,"endTime":1093.785,"body":"which is a much higher dose."},{"startTime":1093.975,"endTime":1101.122,"body":"They'll have a much wider range of symptoms, uh, much longer and more severe, uh,"},{"startTime":1101.122,"endTime":1103.505,"body":"fever, infection, diarrhea, uh, weakness."},{"startTime":1104.165,"endTime":1107.853,"body":"Uh, and the mortality rate of this kind of dose would be somewhere between five"},{"startTime":1107.853,"endTime":1108.345,"body":"and 50%."},{"startTime":1108.365,"endTime":1112.897,"body":"So still the majority of people will recover, but, uh, they will be very sick"},{"startTime":1112.897,"endTime":1116.825,"body":"for, um, a period of time and need, uh, very careful medical care."},{"startTime":1118.725,"endTime":1123.048,"body":"And then at very, very high doses, uh, the effect will be lethal, but that's"},{"startTime":1123.048,"endTime":1123.625,"body":"exceptionally high."},{"startTime":1126.765,"endTime":1131.985,"body":"So that's acute radiation sickness, very small numbers, very, uh, heavy, uh, exposure to radiation."},{"startTime":1132.485,"endTime":1135.705,"body":"The other thing that people, uh, understandably worry about is cancer."},{"startTime":1137.115,"endTime":1143.132,"body":"And, uh, this has been studied, uh, uh, both in, uh, tanavo and in, um,"},{"startTime":1143.132,"endTime":1143.935,"body":"uh, Fukushima."},{"startTime":1144.915,"endTime":1148.598,"body":"And I think it's worth looking at some of the data, and I've chosen Fukushima"},{"startTime":1148.598,"endTime":1149.335,"body":"to do this."},{"startTime":1149.395,"endTime":1154.76,"body":"It was, there was a really heavy study by the World Health Organization, WHO, uh,"},{"startTime":1154.76,"endTime":1155.118,"body":"looking at this, the first thing I want you to look at is the map,"},{"startTime":1155.118,"endTime":1165.135,"body":"uh, on, on, on Fukushima, which is on, on the right of this slide."},{"startTime":1166.035,"endTime":1172.702,"body":"And, uh, in red, that red streak is where people had a high dose, uh,"},{"startTime":1172.702,"endTime":1173.147,"body":"potentially exposure from the plume of radioactive material that moved downwind, uh, away from the"},{"startTime":1173.147,"endTime":1179.815,"body":"radia."},{"startTime":1179.875,"endTime":1185.54,"body":"The, uh, the, the, the reactor, uh, after it had been breached, uh, in blue,"},{"startTime":1185.54,"endTime":1185.918,"body":"um, a much lower, uh, exposure, uh, and other areas outside that really no exposure"},{"startTime":1185.918,"endTime":1193.095,"body":"for practical purposes at all."},{"startTime":1194.195,"endTime":1198.681,"body":"And I wanted to show, uh, really, uh, two things, um, uh, with the graph,"},{"startTime":1198.681,"endTime":1200.775,"body":"uh, on the left of this slide."},{"startTime":1201.875,"endTime":1207.511,"body":"The first is that, um, the, uh, risk of a subsequent cancer is very much"},{"startTime":1207.511,"endTime":1209.015,"body":"dependent on the dose."},{"startTime":1209.715,"endTime":1215.313,"body":"So in the risk of people in absolutely the middle of the red area, the"},{"startTime":1215.313,"endTime":1215.686,"body":"highest exposure in the plume nearest to the reactor have unsurprisingly, a higher risk of"},{"startTime":1215.686,"endTime":1216.059,"body":"cancers than those, uh, than they're the ones on, uh, location one, uh, than those"},{"startTime":1216.059,"endTime":1231.735,"body":"in location h which is much further away from the plume, but still affected."},{"startTime":1232.955,"endTime":1236.735,"body":"The second thing to note is that, um, this varies by age."},{"startTime":1237.635,"endTime":1242.889,"body":"So if children under one are exposed, they have a higher risk, not a massively"},{"startTime":1242.889,"endTime":1243.239,"body":"higher risk, but a slightly higher risk than those, uh, who are older children, uh,"},{"startTime":1243.239,"endTime":1250.245,"body":"and higher, again, than young adults."},{"startTime":1250.385,"endTime":1256.551,"body":"So, age does have some implication here, but, and I think this is where it's"},{"startTime":1256.551,"endTime":1256.962,"body":"important not to get things, uh, see things in a, in the wrong perspective, if"},{"startTime":1256.962,"endTime":1268.885,"body":"you compare the risks as a result of this exposure to someone's lifetime risks, overall,"},{"startTime":1270.465,"endTime":1277.197,"body":"The actual proportionate increase caused by having been exposed to this nuclear, this radiological accident"},{"startTime":1277.197,"endTime":1281.685,"body":"from a nuclear power station, uh, are actually extremely small."},{"startTime":1282.385,"endTime":1287.37,"body":"And the, uh, very, the dark blue or the blue bars at the top of"},{"startTime":1287.37,"endTime":1289.365,"body":"these, uh, are the actual risk."},{"startTime":1289.385,"endTime":1295.085,"body":"And then the gray bar below it is the, uh, lifetime risk, not caused by,"},{"startTime":1295.085,"endTime":1300.405,"body":"uh, the radiological events, but by everything else that someone goes through in life."},{"startTime":1300.405,"endTime":1306.226,"body":"And as you can see, uh, really even in this, uh, very, uh, uh, this"},{"startTime":1306.226,"endTime":1306.614,"body":"relatively heavy exposure compared to others, the actual increase in risk over a, a lifetime,"},{"startTime":1306.614,"endTime":1307.002,"body":"uh, is small, uh, still larger in someone who's a child than, uh, someone who's"},{"startTime":1307.002,"endTime":1318.645,"body":"an adult."},{"startTime":1318.985,"endTime":1324.182,"body":"But still, uh, in both of those, uh, small, and I've, uh, what we have"},{"startTime":1324.182,"endTime":1324.528,"body":"shown on this is, uh, solid cancers, uh, on the left and leukemia, uh, bone,"},{"startTime":1324.528,"endTime":1330.765,"body":"uh, bone marrow cancer."},{"startTime":1331.185,"endTime":1339.405,"body":"Uh, on the right there is, however, one particular cancer, which is, uh, made more"},{"startTime":1339.405,"endTime":1344.885,"body":"likely by exposure, uh, and where the effects are attributable."},{"startTime":1344.885,"endTime":1345.805,"body":"It's a very rare cancer."},{"startTime":1345.955,"endTime":1349.325,"body":"It's made more common by, uh, radiological exposure."},{"startTime":1349.945,"endTime":1353.765,"body":"Uh, but it's still very rare in absolute terms, and that is thyroid cancer."},{"startTime":1355.345,"endTime":1359.645,"body":"And again, uh, worth looking at, uh, really two, two things."},{"startTime":1359.675,"endTime":1364.769,"body":"Firstly, on the right, this is really to demonstrate again, this effect that, um, uh,"},{"startTime":1364.769,"endTime":1368.165,"body":"small children are at a higher risk than, uh, adults."},{"startTime":1368.785,"endTime":1375.165,"body":"And secondly, um, that, uh, women are at higher risk of thyroid cancer than men."},{"startTime":1375.585,"endTime":1379.525,"body":"And that is also true after radiological exposure."},{"startTime":1380.825,"endTime":1383.645,"body":"And you can see this in terms of the lifetime attributable risk."},{"startTime":1384.055,"endTime":1387.995,"body":"Again, uh, on the, uh, on the bit of the graph on the left, what"},{"startTime":1387.995,"endTime":1388.258,"body":"you can see in the gray bars is what people would've had had they not"},{"startTime":1388.258,"endTime":1392.725,"body":"had the exposure."},{"startTime":1393.145,"endTime":1397.445,"body":"The blue bars are the additional, um, risk as a result of exposure."},{"startTime":1397.825,"endTime":1399.285,"body":"And this is in area one."},{"startTime":1399.285,"endTime":1405.779,"body":"This is the people who are most exposed, immediately downwind of the, um, uh, the,"},{"startTime":1405.779,"endTime":1406.645,"body":"the reactor."},{"startTime":1410.675,"endTime":1412.975,"body":"But the numbers involved are very small."},{"startTime":1413.795,"endTime":1419.009,"body":"Um, and, uh, it's important to stress that, uh, thyroid cancer, the great majority of"},{"startTime":1419.009,"endTime":1421.095,"body":"people will not get thyroid cancer."},{"startTime":1421.555,"endTime":1425.095,"body":"And of those who do, uh, the great majority will in fact survive."},{"startTime":1426.865,"endTime":1431.887,"body":"So looking at, um, uh, the snuggle risk, uh, after 30 years, so this is"},{"startTime":1431.887,"endTime":1432.222,"body":"after a long follow-up, the total number of, um, people who had thyroid cancer at"},{"startTime":1432.222,"endTime":1437.245,"body":"all."},{"startTime":1437.245,"endTime":1438.205,"body":"This is all causes."},{"startTime":1438.205,"endTime":1439.565,"body":"This isn't just caused by radiation."},{"startTime":1439.865,"endTime":1443.685,"body":"In the three most affected cancer, uh, countries, was about 11,000."},{"startTime":1444.545,"endTime":1449.355,"body":"Um, but only a fraction of those will have been due to radioactive iodine, and"},{"startTime":1449.355,"endTime":1453.525,"body":"most, uh, would make a full recovery, even of those who've got cancer."},{"startTime":1454.915,"endTime":1460.712,"body":"Very modest increases in other cancers, uh, for those who were exposed, um, uh, to"},{"startTime":1460.712,"endTime":1461.485,"body":"long-term radiation."},{"startTime":1461.985,"endTime":1467.975,"body":"And there was probably a small, but not, not, not substantial, but, but small, but"},{"startTime":1467.975,"endTime":1468.374,"body":"real risk of increased of cardiovascular risk, uh, and also of cataracts, uh, of the"},{"startTime":1468.374,"endTime":1474.365,"body":"eyes."},{"startTime":1475.225,"endTime":1476.445,"body":"All of these are dose related."},{"startTime":1476.825,"endTime":1481.008,"body":"So if you can reduce the dose, you substantially reduce the risk that any of"},{"startTime":1481.008,"endTime":1481.845,"body":"these will occur."},{"startTime":1482.905,"endTime":1487.452,"body":"But to make a point I made earlier, by far the most common, uh, imp"},{"startTime":1487.452,"endTime":1487.755,"body":"implications were mental health issues, where people were very worried that they or their families,"},{"startTime":1487.755,"endTime":1496.245,"body":"uh, will, would be suffering as a result of being, having exposed to radiation."},{"startTime":1496.545,"endTime":1502.036,"body":"And it was actually this concern, there was probably the bigger, uh, risk than the"},{"startTime":1502.036,"endTime":1504.965,"body":"actual risk of cancers and other physical harms."},{"startTime":1509.425,"endTime":1514.363,"body":"So, since the body can deal with very small amounts of radiation and recover well"},{"startTime":1514.363,"endTime":1514.692,"body":"from, uh, low to moderate ones, the key thing is to reduce the dose of"},{"startTime":1514.692,"endTime":1515.021,"body":"radiation and the, after an event, there are three ways to minimize exposure, uh, reduce"},{"startTime":1515.021,"endTime":1515.35,"body":"time, so the amount of time you are, uh, subject to radiation, uh, increased distance"},{"startTime":1515.35,"endTime":1515.68,"body":"from you and the source, and shielding, putting a barrier between you and the radiation"},{"startTime":1515.68,"endTime":1534.445,"body":"source."},{"startTime":1536.545,"endTime":1540.688,"body":"So if you assume a fixed concentration, the risk is broadly proportional to the time"},{"startTime":1540.688,"endTime":1540.965,"body":"exposed."},{"startTime":1541.505,"endTime":1544.285,"body":"So the less time you have exposed, uh, the better."},{"startTime":1544.385,"endTime":1551.445,"body":"And, uh, nuclear, uh, workers are trained very heavily in this distance is very important."},{"startTime":1551.625,"endTime":1556.317,"body":"So at a distance of a few kilometers from a radiation source, there will be"},{"startTime":1556.317,"endTime":1559.445,"body":"no alpha or beta radiation, and gamma will be minimal."},{"startTime":1559.625,"endTime":1565.146,"body":"So keeping away from sources, either the, um, uh, the actual accident or a plume,"},{"startTime":1565.146,"endTime":1565.515,"body":"uh, if you can put distance between you and them, uh, the impact will be"},{"startTime":1565.515,"endTime":1571.405,"body":"extremely small."},{"startTime":1573.385,"endTime":1578.928,"body":"The plume of radioactive material, if there is one, uh, as it moves, is likely"},{"startTime":1578.928,"endTime":1581.885,"body":"to get larger physically, but also to dilute."},{"startTime":1582.065,"endTime":1585.881,"body":"So a larger number will be of people may be exposed to a much lower"},{"startTime":1585.881,"endTime":1586.645,"body":"amount of radiation,"},{"startTime":1588.295,"endTime":1591.943,"body":"But, uh, it is important to track the plume and to make sure people who"},{"startTime":1591.943,"endTime":1592.186,"body":"are likely to be under it are aware of what to do to minimize their"},{"startTime":1592.186,"endTime":1595.835,"body":"risk."},{"startTime":1596.495,"endTime":1602.831,"body":"And finally, uh, shielding, uh, is a very effective way of preventing alpha and beta"},{"startTime":1602.831,"endTime":1603.253,"body":"radiation, putting you a barrier between yourself and the radiation source, and significantly effective, but"},{"startTime":1603.253,"endTime":1612.125,"body":"not completely effective against gamma, uh, radiation."},{"startTime":1612.235,"endTime":1614.165,"body":"I'll go onto that in slightly more detail."},{"startTime":1615.625,"endTime":1623.83,"body":"But to summarize, to reduce your radiation exposure, limiting time, increasing distance and using shielding"},{"startTime":1623.83,"endTime":1626.565,"body":"will significantly reduce the dose."},{"startTime":1627.145,"endTime":1632.15,"body":"And the dose is what predicts how bad the possible outcomes will be, both short"},{"startTime":1632.15,"endTime":1633.485,"body":"term and long term."},{"startTime":1636.545,"endTime":1637.645,"body":"If there is a nuclear event."},{"startTime":1637.985,"endTime":1642.232,"body":"Um, uh, and this is just one of, uh, this is just an example, uh,"},{"startTime":1642.232,"endTime":1643.365,"body":"of, um, plume modeling."},{"startTime":1643.985,"endTime":1649.719,"body":"Uh, there will be, um, expert groups will, uh, be providing a maps of and"},{"startTime":1649.719,"endTime":1653.925,"body":"predictions of where this is gonna go based on weather conditions."},{"startTime":1654.465,"endTime":1658.683,"body":"And this will depend on several factors, how far up it goes, uh, into the"},{"startTime":1658.683,"endTime":1658.965,"body":"atmosphere."},{"startTime":1659.465,"endTime":1665.117,"body":"So much, uh, higher, uh, temperatures will much, uh, any kind of explosion may, uh,"},{"startTime":1665.117,"endTime":1668.885,"body":"loft things much higher than, um, if that doesn't happen."},{"startTime":1669.225,"endTime":1673.256,"body":"And the wind will go in different directions depending on, uh, which, uh, height it"},{"startTime":1673.256,"endTime":1673.525,"body":"is."},{"startTime":1674.105,"endTime":1676.765,"body":"The wind speed and direction is obviously important."},{"startTime":1677.225,"endTime":1682.925,"body":"Uh, things like precipitation, rain, rain, and other events, uh, will, um, have big implications"},{"startTime":1682.925,"endTime":1685.205,"body":"for how quickly it's washed out."},{"startTime":1686.265,"endTime":1691.748,"body":"And also, local factors on the ground will have, uh, big implications for exactly how"},{"startTime":1691.748,"endTime":1692.845,"body":"much concentration occurs."},{"startTime":1693.505,"endTime":1697.437,"body":"So the Met office and others will model it, model any kind of plume, and"},{"startTime":1697.437,"endTime":1700.845,"body":"be able to predict, uh, in which direction it's likely to go next."},{"startTime":1706.425,"endTime":1710.961,"body":"So apart from the people immediately on the site, the plume is the major risk,"},{"startTime":1710.961,"endTime":1711.263,"body":"and this is what will affect, um, uh, anybody who is affected, who isn't immediately"},{"startTime":1711.263,"endTime":1716.405,"body":"on the site."},{"startTime":1717.385,"endTime":1722.432,"body":"And I think that the key thing here is to understand, uh, the, the advice"},{"startTime":1722.432,"endTime":1725.125,"body":"and the reasons for it after an event."},{"startTime":1725.625,"endTime":1731.077,"body":"And the first bit of advice is get inside and then stay inside, don't, uh,"},{"startTime":1731.077,"endTime":1731.805,"body":"venture out."},{"startTime":1732.385,"endTime":1736.396,"body":"Uh, and finally, uh, stay tuned to try and get advice as to when it"},{"startTime":1736.396,"endTime":1739.605,"body":"is going to be safe for you and your family to move."},{"startTime":1741.505,"endTime":1747.883,"body":"The reason for this advice is really, uh, flows from what I said earlier on,"},{"startTime":1747.883,"endTime":1748.308,"body":"uh, about the way in which radiation works, houses, offices, and schools built usually of,"},{"startTime":1748.308,"endTime":1759.365,"body":"uh, brick or concrete or stone, um, provide very good short-term protection."},{"startTime":1759.365,"endTime":1762.885,"body":"We're talking one to three days against alpha and beta radiation."},{"startTime":1762.885,"endTime":1767.301,"body":"They may land on the, uh, on the walls, they may land on the roof,"},{"startTime":1767.301,"endTime":1767.596,"body":"but they will, uh, not be able, the radiation will not penetrate them, uh, and"},{"startTime":1767.596,"endTime":1773.485,"body":"from other elements of radioactive dust."},{"startTime":1774.065,"endTime":1778.502,"body":"But it is important that you then close windows, block off any holes, turn off"},{"startTime":1778.502,"endTime":1782.645,"body":"the air conditioning, so that air is not coming in, uh, from the outside."},{"startTime":1784.355,"endTime":1787.805,"body":"They will also substantially reduce gamma radiation."},{"startTime":1788.385,"endTime":1792.911,"body":"Um, but you want to get as many walls, uh, between you and the outside"},{"startTime":1792.911,"endTime":1793.213,"body":"as possible, because the greater the mass between you and the gamma at the radiation,"},{"startTime":1793.213,"endTime":1801.965,"body":"the smaller the dose you are going to, uh, actually receive due to atte attenuation."},{"startTime":1802.755,"endTime":1804.765,"body":"Cars, on the other hand, are much less safe."},{"startTime":1805.425,"endTime":1809.335,"body":"And this is one of the reasons that, uh, the advice is not to immediately"},{"startTime":1809.335,"endTime":1812.725,"body":"jump in your car, uh, pick up, um, the family and, uh, drive."},{"startTime":1813.075,"endTime":1815.005,"body":"Firstly, other people may well have had the same idea."},{"startTime":1815.005,"endTime":1817.285,"body":"So you maybe be stuck, uh, on the roads."},{"startTime":1817.665,"endTime":1821.533,"body":"And secondly, uh, you will have much less protection in a car than if you"},{"startTime":1821.533,"endTime":1822.565,"body":"are in a building."},{"startTime":1823.785,"endTime":1827.605,"body":"But if there is time to evacuate, uh, do so, but with advice."},{"startTime":1827.905,"endTime":1830.952,"body":"And the reason for that is plumes may not be where you think they are,"},{"startTime":1830.952,"endTime":1831.765,"body":"you can't see them."},{"startTime":1832.305,"endTime":1836.194,"body":"Uh, it's the mapping of them that will tell you where the risk is, where"},{"startTime":1836.194,"endTime":1839.565,"body":"it's going to be, uh, in the next, uh, few hours and days."},{"startTime":1845.065,"endTime":1850.881,"body":"So just to, uh, give some idea of this, um, uh, any house will provide"},{"startTime":1850.881,"endTime":1851.268,"body":"protection, but again, the more walls there are between you and the outside, um, the"},{"startTime":1851.268,"endTime":1857.085,"body":"better."},{"startTime":1857.665,"endTime":1860.775,"body":"Uh, and this is just kind of graphic to give you some idea about where"},{"startTime":1860.775,"endTime":1861.605,"body":"you want to go."},{"startTime":1861.665,"endTime":1866.297,"body":"You want to go essentially into the center of the building, uh, down, uh, down"},{"startTime":1866.297,"endTime":1866.606,"body":"into a cellar, if there is one 'cause that puts more, uh, distance between you"},{"startTime":1866.606,"endTime":1872.165,"body":"and the, uh, roof."},{"startTime":1873.305,"endTime":1878.288,"body":"Um, a typical brick house will reduce this down by about to about point, uh,"},{"startTime":1878.288,"endTime":1879.285,"body":"oh one five."},{"startTime":1879.345,"endTime":1885.467,"body":"So essentially 85% reduction, uh, and a multi-story building will reduce it even further 'cause"},{"startTime":1885.467,"endTime":1888.325,"body":"there's more concrete, uh, and brick involved."},{"startTime":1892.885,"endTime":1896.345,"body":"The next thing you can do and should do is decontamination."},{"startTime":1896.485,"endTime":1901.625,"body":"If you've been outside during a radiological, uh, or indeed nuclear emergency."},{"startTime":1902.685,"endTime":1907.377,"body":"And, um, for radiation, I'll come onto chemicals, which are slightly different, but for radiation,"},{"startTime":1907.377,"endTime":1910.505,"body":"important to understand that a, that minutes don't matter here."},{"startTime":1911.365,"endTime":1913.985,"body":"The key thing is that you do this, uh, effectively."},{"startTime":1914.965,"endTime":1917.625,"body":"So if you've been outside, remove your outer clothes."},{"startTime":1917.625,"endTime":1921.156,"body":"And ideally, if you're on the right kind of environment where you can do this,"},{"startTime":1921.156,"endTime":1921.391,"body":"remove all your clothes, put in, put on clothes that are, uh, are, um, clean"},{"startTime":1921.391,"endTime":1925.865,"body":"and, uh, haven't been contaminated."},{"startTime":1926.415,"endTime":1927.945,"body":"This substantially reduces the risk."},{"startTime":1927.945,"endTime":1932.257,"body":"So any kind of be remitters, are all remitters on those clothes are then off"},{"startTime":1932.257,"endTime":1932.545,"body":"you."},{"startTime":1932.575,"endTime":1933.905,"body":"They're not gonna penetrate."},{"startTime":1933.965,"endTime":1936.345,"body":"Uh, they're going to be, um, some distance away from you."},{"startTime":1936.345,"endTime":1939.625,"body":"Double bag them, put them, uh, somewhere away from where you are."},{"startTime":1941.375,"endTime":1946.425,"body":"Then, uh, shower, uh, using soap, um, uh, lots of water."},{"startTime":1946.885,"endTime":1950.749,"body":"Uh, but don't put in conditioner 'cause that can lead to, uh, things sticking to"},{"startTime":1950.749,"endTime":1951.265,"body":"your hair."},{"startTime":1951.365,"endTime":1952.865,"body":"So just soap and water."},{"startTime":1953.095,"endTime":1956.425,"body":"Mild soap and water, uh, will just get rid of further amounts."},{"startTime":1956.425,"endTime":1959.77,"body":"And this will generally remove more than 90% of the, the radiation on you."},{"startTime":1959.77,"endTime":1962.205,"body":"So this is an effective way, again, of reducing the dose."},{"startTime":1962.685,"endTime":1963.805,"body":"Remembering the dose makes the poison."},{"startTime":1969.245,"endTime":1973.851,"body":"Then it's worth thinking about what other things you can do, particularly the of, from"},{"startTime":1973.851,"endTime":1976.615,"body":"the risks of, uh, radioactive material that's been ingested."},{"startTime":1976.675,"endTime":1982.615,"body":"And the novel accident really provides the model, uh, for which isotopes are important."},{"startTime":1983.795,"endTime":1988.978,"body":"So, quite a lot of radioactive isotopes, um, occurred actually on the site of the,"},{"startTime":1988.978,"endTime":1990.015,"body":"uh, the reactor."},{"startTime":1990.395,"endTime":1998.057,"body":"But, um, uh, only really two became important, uh, in for medical, in medical terms,"},{"startTime":1998.057,"endTime":2002.655,"body":"uh, outside, uh, radioactive iodine and, uh, radioactive cesium."},{"startTime":2003.755,"endTime":2007.095,"body":"And they provided more than 90% of the radioactive material in the plume."},{"startTime":2007.095,"endTime":2008.535,"body":"So they were really, uh, the big risks."},{"startTime":2009.115,"endTime":2012.055,"body":"And they have slightly different, um, uh, properties."},{"startTime":2012.925,"endTime":2017.735,"body":"Radioactive iodine has a, uh, relatively short half-life just over a week."},{"startTime":2018.395,"endTime":2022.941,"body":"So that means that the dose is going to be dropping very rapidly over the"},{"startTime":2022.941,"endTime":2023.244,"body":"first two or three weeks, uh, and or decay way in months to a point"},{"startTime":2023.244,"endTime":2030.215,"body":"where for practical purposes, it's not adding much risk."},{"startTime":2031.565,"endTime":2034.415,"body":"Seizing, on the other hand, has a much longer half-life."},{"startTime":2034.415,"endTime":2038.403,"body":"So this will, this will survive in the environment for, uh, a much longer period"},{"startTime":2038.403,"endTime":2038.935,"body":"of time."},{"startTime":2040.515,"endTime":2043.175,"body":"But they do actually have different medical, uh, properties."},{"startTime":2044.435,"endTime":2047.795,"body":"Um, iodine, uh, generally iodine one three."},{"startTime":2047.815,"endTime":2052.488,"body":"One is a product of uranium and plutonium, uh, both of which may be used"},{"startTime":2052.488,"endTime":2055.915,"body":"or either or both of which may be in the reactor."},{"startTime":2056.705,"endTime":2058.435,"body":"It's also used, uh, medical treatment."},{"startTime":2059.054,"endTime":2063.034,"body":"Uh, most of its radiation is beta, so it's quite short, uh, range."},{"startTime":2063.614,"endTime":2066.802,"body":"And therefore, the risk is if you ingest it, uh, in some way, there's a"},{"startTime":2066.802,"endTime":2068.715,"body":"small amount, a much smaller amount of gamma radiation."},{"startTime":2070.735,"endTime":2077.018,"body":"The reason it's important, uh, however, is that it's taken up by and concentrated by"},{"startTime":2077.018,"endTime":2078.275,"body":"the thyroid gland."},{"startTime":2078.335,"endTime":2083.995,"body":"And that is because the main, uh, thyroid hormone is based on iodine."},{"startTime":2083.995,"endTime":2090.458,"body":"So the thyroid gland, uh, seizes iodine that's passing and concentrates it in the gland,"},{"startTime":2090.458,"endTime":2093.475,"body":"uh, to make, uh, thyroid, uh, hormones."},{"startTime":2095.094,"endTime":2098.794,"body":"And the problem with this, therefore, is you get a very heavy concentration of the"},{"startTime":2098.794,"endTime":2099.041,"body":"iodine, which might, at the very low levels in the rest of the body, really"},{"startTime":2099.041,"endTime":2103.235,"body":"has minimal effects."},{"startTime":2103.235,"endTime":2108.681,"body":"Because it's highly concentrated in this area, it is, uh, therefore, and producing beta emissions,"},{"startTime":2108.681,"endTime":2112.675,"body":"it therefore can cause local damage to the thyroid, uh, gland."},{"startTime":2113.835,"endTime":2115.615,"body":"And this can do, uh, two things."},{"startTime":2116.155,"endTime":2120.036,"body":"Uh, it can damage the thyroid glands so it doesn't continue to produce its, uh,"},{"startTime":2120.036,"endTime":2120.295,"body":"hormone."},{"startTime":2120.475,"endTime":2125.855,"body":"Now, that is a nuisance, but it is an entirely, uh, manageable process."},{"startTime":2126.005,"endTime":2129.095,"body":"Lots of people have to have thyroid, uh, replacement therapy."},{"startTime":2129.515,"endTime":2134.21,"body":"Uh, it's really then means people have to have thyroid replacement therapy subsequently, uh, with,"},{"startTime":2134.21,"endTime":2135.775,"body":"uh, just oral, oral drugs."},{"startTime":2136.275,"endTime":2140.685,"body":"Uh, but there is this increased risk, which I talked about earlier of thyroid cancer."},{"startTime":2141.835,"endTime":2147.626,"body":"Important to note that radioactive, uh, iodine of different forms, uh, is used also for"},{"startTime":2147.626,"endTime":2148.013,"body":"treatment, sometimes for an overactive thyroid, uh, and sometimes in fact, for treatment of cancers"},{"startTime":2148.013,"endTime":2153.805,"body":"themselves."},{"startTime":2154.385,"endTime":2158.401,"body":"Uh, so it is given, but obviously that's in a environment where you're trying to"},{"startTime":2158.401,"endTime":2159.205,"body":"treat a disease."},{"startTime":2160.945,"endTime":2166.917,"body":"So this issue about radioactive iodine in the thyroid, uh, means that it is worth,"},{"startTime":2166.917,"endTime":2167.315,"body":"if you are, know, you're about to be exposed, taking iodine to reduce the risk"},{"startTime":2167.315,"endTime":2174.085,"body":"of thyroid cancer."},{"startTime":2175.025,"endTime":2180.183,"body":"And the reason this works is by flooding the body with iodine just before the"},{"startTime":2180.183,"endTime":2180.527,"body":"event, uh, the, uh, thyroid is then taken up a huge amount of iodine, uh,"},{"startTime":2180.527,"endTime":2180.871,"body":"and, um, is, uh, much less likely to grab radioactive iodine, uh, as it goes"},{"startTime":2180.871,"endTime":2194.285,"body":"past, reduces the risk of it being concentrated in thyroid subsequently."},{"startTime":2195.945,"endTime":2201.466,"body":"So for people exposed to significant risks from inhaling iodine, uh, from the plume, uh,"},{"startTime":2201.466,"endTime":2201.835,"body":"the recommendation is to have stable iodine, uh, given between 24 hours before and two"},{"startTime":2201.835,"endTime":2207.725,"body":"hours after."},{"startTime":2207.785,"endTime":2211.245,"body":"If you give it later than that, it actually can do more harm than good."},{"startTime":2211.245,"endTime":2212.885,"body":"So you definitely want to do it before the event."},{"startTime":2214.775,"endTime":2219.995,"body":"Uh, and then longer term risks can occur from, uh, milk products, uh, and food."},{"startTime":2220.375,"endTime":2224.44,"body":"Uh, but these can be picked up by people detecting the radiation and essentially taking"},{"startTime":2224.44,"endTime":2225.795,"body":"them out of, uh, production."},{"startTime":2225.895,"endTime":2231.278,"body":"So that side of things, uh, will be dealt with by, um, safety, uh, measures"},{"startTime":2231.278,"endTime":2232.355,"body":"on food subsequently."},{"startTime":2232.375,"endTime":2237.462,"body":"So it's really that initial risk under the radioactive plume, those who are not under"},{"startTime":2237.462,"endTime":2240.515,"body":"the plume and not at risk from radioactive iodine."},{"startTime":2243.475,"endTime":2247.975,"body":"Cesium, uh, 1 3 7, uh, is, as I say, longer lasting."},{"startTime":2248.795,"endTime":2254.855,"body":"Um, it's also water soluble and potentially stable, so it can spread through the environment."},{"startTime":2256.035,"endTime":2260.877,"body":"It is taken up by humans, but it's, uh, very rapidly, um, excreted in the"},{"startTime":2260.877,"endTime":2262.815,"body":"same way the potassium is excreted."},{"startTime":2262.815,"endTime":2267.915,"body":"So it's actually quite rare that people will get significant amounts of cesium concentrating in"},{"startTime":2267.915,"endTime":2268.255,"body":"the body, remembering that the body is extremely good at dealing with low levels of"},{"startTime":2268.255,"endTime":2275.055,"body":"radiation and recovering from moderate levels."},{"startTime":2275.195,"endTime":2279.611,"body":"So, uh, the biggest problem from caesium really is the fact that it has a"},{"startTime":2279.611,"endTime":2280.495,"body":"relatively long half-life."},{"startTime":2280.995,"endTime":2285.565,"body":"Uh, and, uh, you can see, uh, on this map, uh, where caesium was deposited"},{"startTime":2285.565,"endTime":2286.175,"body":"in Europe."},{"startTime":2286.515,"endTime":2293.067,"body":"Uh, and these, this has implications for subsequent agriculture in those areas, potentially where red"},{"startTime":2293.067,"endTime":2294.815,"body":"is, uh, high amounts,"},{"startTime":2297.725,"endTime":2301.145,"body":"It is very unlikely that tap water will be contaminated to a significant degree."},{"startTime":2301.325,"endTime":2303.785,"body":"So that's not a worry that people should have."},{"startTime":2303.785,"endTime":2306.385,"body":"They can still drink tap water unless told otherwise."},{"startTime":2307.005,"endTime":2312.067,"body":"Um, and anything that's indoors in your house, indeed, in a supermarket before the accident"},{"startTime":2312.067,"endTime":2315.105,"body":"is safe to consume, it won't have been contaminated."},{"startTime":2315.905,"endTime":2319.325,"body":"The only real risk is vegetables outside when contamination occurred."},{"startTime":2319.345,"endTime":2324.134,"body":"So if you've got a kind of plot outside, then, uh, don't start digging up"},{"startTime":2324.134,"endTime":2328.285,"body":"your, um, uh, your, uh, lettuce or whatever it is, uh, straight afterwards."},{"startTime":2328.695,"endTime":2329.685,"body":"Seems an obvious point."},{"startTime":2330.225,"endTime":2334.38,"body":"Uh, and, um, remembering that over 90% of radiation from food is naturally occurring and"},{"startTime":2334.38,"endTime":2335.765,"body":"at very, very low levels."},{"startTime":2336.385,"endTime":2339.875,"body":"Uh, what what will happen then is there'll be a safety assessment of all the"},{"startTime":2339.875,"endTime":2343.365,"body":"different food stuffs, and where there's a risk, it'll be removed from the food chain."},{"startTime":2343.945,"endTime":2347.095,"body":"So, um, the risk really in, in, from this point of view is likely to"},{"startTime":2347.095,"endTime":2347.725,"body":"be very small."},{"startTime":2350.345,"endTime":2354.845,"body":"So that's the, um, uh, the what to do after a radiological event."},{"startTime":2355.065,"endTime":2357.925,"body":"And this is, uh, the majority of the talk."},{"startTime":2357.925,"endTime":2361.925,"body":"But I wanted now just to talk about some, uh, events, which we hope will"},{"startTime":2361.925,"endTime":2365.925,"body":"never happen again, but it is worth understanding a bit about the medicine around these."},{"startTime":2366.105,"endTime":2369.605,"body":"And the first of these is a nuclear device explosion, a nuclear bomb."},{"startTime":2371.185,"endTime":2375.885,"body":"Uh, this will cause, um, death and destruction and disability, our three roots."},{"startTime":2376.305,"endTime":2378.245,"body":"The first is blast straight, blast."},{"startTime":2378.305,"endTime":2379.605,"body":"It, it is an explosion."},{"startTime":2379.605,"endTime":2383.085,"body":"It's a very large explosion, uh, and people will be killed by that explosion."},{"startTime":2384.665,"endTime":2388.205,"body":"The second is thermal flash where people, uh, get burns."},{"startTime":2388.785,"endTime":2391.245,"body":"And the third, uh, is radiation."},{"startTime":2391.245,"endTime":2394.885,"body":"Radiation, of course, is the one that's specific to, uh, nuclear devices."},{"startTime":2396.865,"endTime":2400.887,"body":"The great majority of the death will in fact be from, uh, blast and the"},{"startTime":2400.887,"endTime":2402.765,"body":"fast storm, uh, that goes with it."},{"startTime":2402.825,"endTime":2407.925,"body":"So, um, those two, uh, are the, uh, what will will kill the great majority"},{"startTime":2407.925,"endTime":2408.605,"body":"of people."},{"startTime":2408.665,"endTime":2413.605,"body":"And did so, uh, in, uh, in, uh, the, um, uh, second World War,"},{"startTime":2415.285,"endTime":2420.523,"body":"Depending on the nuclear device size and variety of other things, there may be a"},{"startTime":2420.523,"endTime":2420.873,"body":"zone where people survive the blast, but have a lethal, severe or moderate amount of"},{"startTime":2420.873,"endTime":2429.255,"body":"radiation sickness For many nuclear devices that won't actually happen."},{"startTime":2429.395,"endTime":2434.636,"body":"The, the blast, uh, will essentially kill everyone who's going to be killed, uh, anyway,"},{"startTime":2434.636,"endTime":2435.335,"body":"uh, unfortunately."},{"startTime":2435.595,"endTime":2440.545,"body":"But, um, the, some devices that may be a sort of outer layer where radiation"},{"startTime":2440.545,"endTime":2441.535,"body":"sickness is important."},{"startTime":2442.235,"endTime":2447.918,"body":"And then the radioactive plume principles are exactly the same as for a civil, um,"},{"startTime":2447.918,"endTime":2449.055,"body":"uh, radiological event."},{"startTime":2449.435,"endTime":2454.248,"body":"Uh, you get indoors and you stay indoors, uh, until you're given advice, um, to"},{"startTime":2454.248,"endTime":2456.815,"body":"move, because it's become safer to do so."},{"startTime":2457.995,"endTime":2463.981,"body":"One slight difference is that radioactive iodine is much less important in, uh, in plumes"},{"startTime":2463.981,"endTime":2466.775,"body":"provided, uh, which are created this way."},{"startTime":2467.075,"endTime":2470.895,"body":"And therefore, getting stable iodine is of practically much less importance."},{"startTime":2473.705,"endTime":2478.799,"body":"Now, the physics of this, I'm not gonna go through, but just to say that,"},{"startTime":2478.799,"endTime":2479.138,"body":"um, the size of the nuclear device will determine whether there is a zone of"},{"startTime":2479.138,"endTime":2479.478,"body":"people who get acute radiation sickness, but who were not killed in the initial, um,"},{"startTime":2479.478,"endTime":2490.685,"body":"blast and fire in general."},{"startTime":2490.835,"endTime":2496.839,"body":"What this, this, this, uh, graph is demonstrating is that, um, the, uh, the dark"},{"startTime":2496.839,"endTime":2497.24,"body":"blue line, uh, is the radiation injuries at a high enough level to cause very"},{"startTime":2497.24,"endTime":2503.645,"body":"significant harm."},{"startTime":2504.105,"endTime":2509.19,"body":"And as you can see in small nuclear devices, there may be a group of,"},{"startTime":2509.19,"endTime":2509.529,"body":"uh, quite a significant group of people who have, uh, radiation injury beyond the blast"},{"startTime":2509.529,"endTime":2518.005,"body":"radius for very large, uh, blast, um, very large nuclear devices."},{"startTime":2518.505,"endTime":2524.205,"body":"Uh, essentially everybody would've been killed in the blast and fire, uh, unfortunately, but, uh,"},{"startTime":2524.205,"endTime":2527.245,"body":"let us hope that this never occurs again."},{"startTime":2527.785,"endTime":2535.63,"body":"Um, uh, in the future within this, there's a lot of ra vari variation, um,"},{"startTime":2535.63,"endTime":2539.815,"body":"uh, buildings, terrain, what's hills variety of build."},{"startTime":2540.035,"endTime":2545.708,"body":"All, all, all these kind of environments will have implications for both the effects of"},{"startTime":2545.708,"endTime":2546.086,"body":"the blast injury, uh, and, uh, burns and radiation in due course, uh, and how"},{"startTime":2546.086,"endTime":2557.055,"body":"high up the, uh, the, um, devices when it explodes, uh, will also have invocations."},{"startTime":2557.515,"endTime":2561.396,"body":"Uh, but I think probably the details of this are, are, are unnecessary at this"},{"startTime":2561.396,"endTime":2561.655,"body":"point."},{"startTime":2561.675,"endTime":2565.368,"body":"The point is, uh, unfortunately, with a large event, most people will die in the"},{"startTime":2565.368,"endTime":2565.615,"body":"blast."},{"startTime":2566.395,"endTime":2566.615,"body":"Um,"},{"startTime":2569.995,"endTime":2575.373,"body":"So now to move on to, uh, chemicals, uh, and I'm really just gonna talk"},{"startTime":2575.373,"endTime":2575.732,"body":"here about chemical warfare agents, but some of the points that I'm making in general"},{"startTime":2575.732,"endTime":2585.055,"body":"are applied to all contamination with dangerous chemicals at high enough doses."},{"startTime":2585.515,"endTime":2592.433,"body":"Uh, many chemicals and drugs given quite perfectly appropriately by, uh, doctors, uh, can be"},{"startTime":2592.433,"endTime":2592.895,"body":"toxic."},{"startTime":2593.595,"endTime":2597.637,"body":"And some are indeed occasionally used as poisons where people deliberately give someone, uh, a"},{"startTime":2597.637,"endTime":2599.255,"body":"much higher dose than is safe."},{"startTime":2599.875,"endTime":2604.999,"body":"Uh, but, um, uh, in general, uh, if you keep within the, the recommended dose,"},{"startTime":2604.999,"endTime":2608.415,"body":"uh, they will do, uh, much more good than harm."},{"startTime":2609.935,"endTime":2615.815,"body":"A much smaller number of chemicals have been designed deliberately to kill and maim humans."},{"startTime":2616.755,"endTime":2618.935,"body":"And there are three classes in particular."},{"startTime":2618.935,"endTime":2624.455,"body":"There are some others, but three in particular have been used, uh, unfortunately, uh, over,"},{"startTime":2624.455,"endTime":2626.295,"body":"over, uh, our recent history."},{"startTime":2627.075,"endTime":2631.975,"body":"The first group are the blistering agents of which mustard gas is the best known."},{"startTime":2633.555,"endTime":2639.219,"body":"The second are the choking agents, um, uh, of which chlorine and sine, uh, are"},{"startTime":2639.219,"endTime":2639.975,"body":"best known."},{"startTime":2639.975,"endTime":2643.895,"body":"And, uh, all of these, unfortunately, were used in the first World War."},{"startTime":2644.405,"endTime":2645.895,"body":"I'll go through them in a bit more detail."},{"startTime":2646.155,"endTime":2650.535,"body":"And then the third group are the nerve agents, especially the organophosphates,"},{"startTime":2654.265,"endTime":2655.575,"body":"Start with the blistering agents."},{"startTime":2656.315,"endTime":2661.511,"body":"Um, there are several of them, but the three probably best known sulfur mustard, I'll"},{"startTime":2661.511,"endTime":2661.858,"body":"say mustard gas, uh, cyte and nitrogen mustard, uh, are the ones that, uh, were"},{"startTime":2661.858,"endTime":2667.055,"body":"used."},{"startTime":2668.155,"endTime":2670.735,"body":"And you can see, uh, on, on the right of this."},{"startTime":2671.305,"endTime":2676.527,"body":"Um, some of the studies of, uh, these agents, uh, on people at different concentrations,"},{"startTime":2676.527,"endTime":2678.965,"body":"uh, on the effects on people's skin."},{"startTime":2680.825,"endTime":2684.085,"body":"Um, sulfur mustard is a gas or an oily liquid."},{"startTime":2684.105,"endTime":2685.725,"body":"So the actual, it's not just a gas."},{"startTime":2685.785,"endTime":2689.658,"body":"You actually can have it, uh, as a li in liquid form, and therefore people"},{"startTime":2689.658,"endTime":2691.725,"body":"touch it and get bl blistering from that."},{"startTime":2692.145,"endTime":2697.755,"body":"And it causes its damage by, uh, skin contact, uh, eye contact and inhalation, and"},{"startTime":2697.755,"endTime":2703.365,"body":"all of these, it causes severe burns and blisters eye damage and lung da damage."},{"startTime":2703.635,"endTime":2705.165,"body":"It's not, uh, often not immediate."},{"startTime":2705.165,"endTime":2709.805,"body":"It can be delayed by up to 24 hours as it's heavier than air."},{"startTime":2709.905,"endTime":2713.055,"body":"And this is important if you want me to get outta an environment where this"},{"startTime":2713.055,"endTime":2713.685,"body":"is, uh, there."},{"startTime":2713.705,"endTime":2715.085,"body":"So it sinks to low lying areas."},{"startTime":2715.085,"endTime":2718.998,"body":"It's one of the reasons it was used as a military agent, 'cause it's sunk"},{"startTime":2718.998,"endTime":2721.085,"body":"down into trenches and foxholes and so on."},{"startTime":2721.705,"endTime":2725.365,"body":"Uh, and, and, and normal weather conditions, it lasts about one to two days."},{"startTime":2725.545,"endTime":2728.085,"body":"It can, uh, be slightly longer in cold weather."},{"startTime":2729.905,"endTime":2734.862,"body":"The key, if someone is exposed to this, is get them out into fresh air"},{"startTime":2734.862,"endTime":2736.845,"body":"and remove all their clothes immediately."},{"startTime":2736.905,"endTime":2742.365,"body":"So, unlike radiation where speed is much less important, uh, speed really is absolutely essential."},{"startTime":2742.365,"endTime":2745.965,"body":"You've just got to do it immediately and then go on to do decontamination, which"},{"startTime":2745.965,"endTime":2746.685,"body":"I'll come onto."},{"startTime":2747.895,"endTime":2752.31,"body":"There are no antidotes to these agents, but the great majority of people will survive"},{"startTime":2752.31,"endTime":2752.605,"body":"them."},{"startTime":2753.065,"endTime":2757.845,"body":"But it's exceptionally painful for the period, uh, over the, uh, next few weeks."},{"startTime":2758.385,"endTime":2762.925,"body":"Um, and it may cause some scarring, so extremely unpleasant."},{"startTime":2763.305,"endTime":2763.965,"body":"Uh, agents"},{"startTime":2767.635,"endTime":2773.297,"body":"Subsequently, uh, master gas agents, however, were then used, um, because of their damage to"},{"startTime":2773.297,"endTime":2773.675,"body":"cells."},{"startTime":2774.375,"endTime":2779.315,"body":"Um, uh, they were then, uh, studied for their effects, um, in medicines."},{"startTime":2779.815,"endTime":2784.906,"body":"And from them, several drugs were in fact developed, which are, some of which are"},{"startTime":2784.906,"endTime":2785.246,"body":"still in use, um, because they cause damage to, to rapidly dividing cells, that's really"},{"startTime":2785.246,"endTime":2792.035,"body":"where they cause the most damage."},{"startTime":2792.535,"endTime":2796.152,"body":"Um, this can lead, uh, it was seen that this led to a drop in"},{"startTime":2796.152,"endTime":2796.635,"body":"white cells."},{"startTime":2797.855,"endTime":2802.955,"body":"And as a result of that, uh, doctors initially in the States, um, uh, started"},{"startTime":2802.955,"endTime":2805.675,"body":"trying to see if this could be used."},{"startTime":2805.855,"endTime":2809.595,"body":"Uh, these drugs could be used to treat, uh, the cancers of the blood cells."},{"startTime":2810.015,"endTime":2813.555,"body":"Uh, and the first patient who had this was someone with lymphoma."},{"startTime":2814.775,"endTime":2821.243,"body":"And the drug significantly improved their lymphoma, uh, with repeated doses, uh, but eventually they"},{"startTime":2821.243,"endTime":2821.675,"body":"relapse."},{"startTime":2821.735,"endTime":2824.195,"body":"But this was really the start of, um, chemotherapy."},{"startTime":2824.375,"endTime":2830.155,"body":"So chemotherapy actually derives in part from these, uh, appalling, uh, military agents."},{"startTime":2832.015,"endTime":2837.931,"body":"Uh, then, um, various, uh, pharmacologists, uh, use use those principles and found mechanisms to"},{"startTime":2837.931,"endTime":2841.875,"body":"make them much less toxic to the general inter individuals."},{"startTime":2842.335,"endTime":2847.754,"body":"Uh, and this led to a se a series of drugs, which are still used,"},{"startTime":2847.754,"endTime":2848.115,"body":"uh, today in chemotherapy, uh, probably the most widely used is a drug called Chlorambacil,"},{"startTime":2848.115,"endTime":2848.477,"body":"uh, which, um, is essentially derived from this by several removes, still uses a chemotherapy"},{"startTime":2848.477,"endTime":2861.845,"body":"agent, uh, and also used for severe immune diseases."},{"startTime":2862.065,"endTime":2869.658,"body":"So, uh, this has gone into medicine from, uh, military agent, um, over, over many"},{"startTime":2869.658,"endTime":2870.165,"body":"years."},{"startTime":2873.305,"endTime":2878.532,"body":"The second groups of agents are the choking or pulmonary agents that affect the lungs,"},{"startTime":2878.532,"endTime":2878.88,"body":"uh, of which the best known are chlorine, gas and sine very extensively used in"},{"startTime":2878.88,"endTime":2884.805,"body":"World War I."},{"startTime":2885.305,"endTime":2888.405,"body":"Um, uh, but they're also dual use."},{"startTime":2888.405,"endTime":2891.645,"body":"They're used a lot in chemical processes."},{"startTime":2891.645,"endTime":2895.285,"body":"So these are drugs which were known in industry, uh, for other reasons."},{"startTime":2896.145,"endTime":2898.365,"body":"Uh, a very high dose is, again, a very low dose."},{"startTime":2898.545,"endTime":2900.565,"body":"Uh, it's entirely manageable, very high doses."},{"startTime":2900.565,"endTime":2905.445,"body":"They cause burning sensations, the lungs, eyes, uh, coughing in very high doses."},{"startTime":2905.445,"endTime":2906.525,"body":"You get fluid on the lungs."},{"startTime":2906.525,"endTime":2911.765,"body":"Pulmonary edema and phosgene, uh, can additionally cause heart problems."},{"startTime":2912.945,"endTime":2918.213,"body":"Uh, like with the, um, the mustard, uh, group, the blistering group, the key thing"},{"startTime":2918.213,"endTime":2921.725,"body":"is getaway and get clothes off as fast as possible."},{"startTime":2922.235,"endTime":2927.287,"body":"Most people will make a, a full recovery in between seven and 14 days, but,"},{"startTime":2927.287,"endTime":2929.645,"body":"um, extremely unpleasant in the intervening period."},{"startTime":2930.065,"endTime":2935.485,"body":"Uh, phosgene has a higher mortality rate, but still the majority recovered."},{"startTime":2935.485,"endTime":2939.085,"body":"But Phosgene, in fact, was the chemical agent, which killed the most people, uh, in"},{"startTime":2939.085,"endTime":2939.805,"body":"World War I."},{"startTime":2944.985,"endTime":2949.061,"body":"The third big group, um, not, uh, used, uh, in this way in in World"},{"startTime":2949.061,"endTime":2949.605,"body":"War I."},{"startTime":2949.705,"endTime":2954.165,"body":"Um, but subsequently developed are the organophosphates and the carbonates."},{"startTime":2954.165,"endTime":2955.525,"body":"These are the nerve agents."},{"startTime":2955.945,"endTime":2958.125,"body":"Um, that's how they're popularly referred."},{"startTime":2959.715,"endTime":2966.055,"body":"These were originally developed, um, uh, by a as, uh, and insecticides and pesticides, and"},{"startTime":2966.055,"endTime":2966.478,"body":"we still use 'em, this class of drugs in very different doses and different formulations"},{"startTime":2966.478,"endTime":2973.665,"body":"for that purpose."},{"startTime":2973.795,"endTime":2979.051,"body":"Sheep dips, for example, which have organ, organ phosphates to help kill ticks, uh, if,"},{"startTime":2979.051,"endTime":2981.505,"body":"uh, you treat, uh, yourself or children."},{"startTime":2981.925,"endTime":2984.665,"body":"Uh, with Malian, it's an incredibly low organ."},{"startTime":2984.665,"endTime":2987.865,"body":"Organ phosphate used to treat headly and scabies a very effective drug."},{"startTime":2987.865,"endTime":2995.002,"body":"Doesn't, uh, have, uh, good any problems, uh, uh, of, of a significant sort, uh,"},{"startTime":2995.002,"endTime":2999.285,"body":"with toxicity, um, uh, if used as, as intended."},{"startTime":2999.945,"endTime":3004.645,"body":"So it was actually developed for medical and agricultural use."},{"startTime":3006.825,"endTime":3009.645,"body":"Um, the way they work is via the acetylcholine system."},{"startTime":3011.025,"endTime":3017.765,"body":"And, um, a, an enzyme that breaks down acetylcholine, uh, called ttyl cone esterase."},{"startTime":3019.105,"endTime":3025.578,"body":"Um, AST acetylcholine is used by lots of different species, uh, human, but also insects,"},{"startTime":3025.578,"endTime":3030.325,"body":"um, as a neurotransmitter, uh, in multiple parts of the body."},{"startTime":3030.355,"endTime":3036.857,"body":"It's, it's, it's really widely used across, um, uh, all, all of, uh, biology in"},{"startTime":3036.857,"endTime":3037.725,"body":"neuromuscular junctions."},{"startTime":3037.865,"endTime":3039.445,"body":"It causes muscles to contract."},{"startTime":3039.795,"endTime":3045.202,"body":"It's also affects the brain, uh, can affect the, as used in the brain sympathetic"},{"startTime":3045.202,"endTime":3046.645,"body":"and parasympathetic nervous system."},{"startTime":3046.705,"endTime":3049.085,"body":"So it's got large numbers of effects."},{"startTime":3049.505,"endTime":3054.411,"body":"And what normally happens is the, uh, ACON is released, it then binds the receptor,"},{"startTime":3054.411,"endTime":3054.738,"body":"it leads to the action, and then the asoc conone esterase breaks it down in"},{"startTime":3054.738,"endTime":3059.645,"body":"nanoseconds."},{"startTime":3059.945,"endTime":3062.645,"body":"So the system turns on and then immediately turns off."},{"startTime":3062.645,"endTime":3065.285,"body":"And s more AOL coline is re released."},{"startTime":3066.095,"endTime":3071.885,"body":"These agents, uh, stop the breaking down of the AOL coline, uh, acetylcholine."},{"startTime":3072.265,"endTime":3075.165,"body":"And because of that, the system is then always on."},{"startTime":3075.195,"endTime":3077.405,"body":"It's not in the kind of balance, it's always on."},{"startTime":3077.625,"endTime":3079.565,"body":"And this is what causes, uh, the damage."},{"startTime":3082.665,"endTime":3087.191,"body":"Uh, these agents at high doses, and the doses used to actually damage humans deliberately,"},{"startTime":3087.191,"endTime":3087.493,"body":"rather than as a, an insecticide or to treat, um, conditions can be delivered in"},{"startTime":3087.493,"endTime":3092.925,"body":"a variety of ways."},{"startTime":3092.925,"endTime":3098.515,"body":"They can be delivered as gases, uh, which the most well known is sarin, and"},{"startTime":3098.515,"endTime":3101.125,"body":"they can also be delivered as liquids."},{"startTime":3101.265,"endTime":3106.5,"body":"In military terms, this is a area denial agent, uh, uh, of which the best"},{"startTime":3106.5,"endTime":3108.245,"body":"known, uh, was, uh, vx."},{"startTime":3108.625,"endTime":3113.992,"body":"But in the UK unfortunately, we've also, uh, had, uh, due to deliberate, uh, use,"},{"startTime":3113.992,"endTime":3118.645,"body":"uh, Novi shock, uh, which is another of these gon phosphate, um, agents."},{"startTime":3120.225,"endTime":3129.022,"body":"The symptoms of phosphate poisoning are twitching, shortness of breath, diarrhea, involuntary tearing, uh, pinpoint"},{"startTime":3129.022,"endTime":3129.608,"body":"pupils in a moderate dose and in higher doses, uh, still convulsions, coma, cardiac arrest,"},{"startTime":3129.608,"endTime":3140.165,"body":"respiratory arrest, and death."},{"startTime":3141.755,"endTime":3145.815,"body":"So, as with all of these things, dose makes the poison very, very small."},{"startTime":3146.495,"endTime":3149.655,"body":"Exposure will be dealt with by the body relatively, uh, quickly."},{"startTime":3150.195,"endTime":3155.934,"body":"Uh, if you've got, uh, very high doses, uh, potentially lethal amounts, there are treatments"},{"startTime":3155.934,"endTime":3156.317,"body":"for this, um, of which the most, uh, widely used is atropin, uh, which blocks"},{"startTime":3156.317,"endTime":3163.205,"body":"some of the receptors."},{"startTime":3163.205,"endTime":3164.685,"body":"So it reduces some of the effect of this."},{"startTime":3164.705,"endTime":3169.521,"body":"So it, it blocks some of the acetylcholine receptors that this acetylcholine is, uh, is"},{"startTime":3169.521,"endTime":3170.485,"body":"going to affect."},{"startTime":3170.985,"endTime":3174.565,"body":"Um, but, uh, the treatment is only moderately effective."},{"startTime":3174.865,"endTime":3179.053,"body":"Um, and you have to wait until, uh, the system, uh, has recovered, which can"},{"startTime":3179.053,"endTime":3182.405,"body":"take a very long time if people do make a full recovery"},{"startTime":3185.935,"endTime":3187.355,"body":"For all of these chemical agents."},{"startTime":3187.375,"endTime":3190.731,"body":"And the same is true if you're talking about industrial chemicals that people are exposed"},{"startTime":3190.731,"endTime":3190.955,"body":"to."},{"startTime":3191.695,"endTime":3197.645,"body":"Uh, decontamination is absolutely critical, and there is a real need for speed in decontamination"},{"startTime":3197.645,"endTime":3198.835,"body":"with chemical agents."},{"startTime":3199.015,"endTime":3205.64,"body":"In contrast to, uh, the, um, uh, radiological in, uh, incidents where, uh, its speed"},{"startTime":3205.64,"endTime":3206.965,"body":"is less essential."},{"startTime":3208.445,"endTime":3210.425,"body":"You need to remove all clothes possible."},{"startTime":3211.245,"endTime":3213.265,"body":"Uh, don't pull things over the head."},{"startTime":3213.365,"endTime":3216.893,"body":"If you've got scissors, just cut them off to avoid them being smeared over the"},{"startTime":3216.893,"endTime":3218.305,"body":"face, the eyes, and so on."},{"startTime":3219.015,"endTime":3222.892,"body":"Then they should be double backed and put a long way away from anywhere where,"},{"startTime":3222.892,"endTime":3224.185,"body":"uh, an a anyone is."},{"startTime":3225.965,"endTime":3229.505,"body":"If it's an oily substance, then dab it off quickly initially."},{"startTime":3229.925,"endTime":3231.945,"body":"Uh, this is to avoid it being spread more widely."},{"startTime":3232.005,"endTime":3235.375,"body":"So, um, using kitchen towels, for example, would be, uh, a, a good way of"},{"startTime":3235.375,"endTime":3235.825,"body":"doing that."},{"startTime":3236.205,"endTime":3242.447,"body":"And then go onto wash shower, ideally with copious amounts of water, uh, and potentially"},{"startTime":3242.447,"endTime":3244.945,"body":"mild soap that basically is decontamination."},{"startTime":3245.565,"endTime":3249.496,"body":"Uh, and then remove contact lenses, which could be, uh, could have concentrated some of"},{"startTime":3249.496,"endTime":3250.545,"body":"the chemicals inside them."},{"startTime":3251.125,"endTime":3256.683,"body":"So, um, removing all clothes, removing excess oily material, and then, uh, lots and lots"},{"startTime":3256.683,"endTime":3257.425,"body":"of water."},{"startTime":3257.885,"endTime":3262.945,"body":"And mild soap really is the way to reduce the dose as much as possible."},{"startTime":3266.685,"endTime":3273.522,"body":"So this is, that's really an overview, uh, of the major radiological nuclear and chemical"},{"startTime":3273.522,"endTime":3277.625,"body":"deliberate chemical incidents and accidents throughout all of this."},{"startTime":3277.765,"endTime":3281.425,"body":"The point I was trying to emphasize is the dose makes the poison."},{"startTime":3282.205,"endTime":3287.015,"body":"And therefore, since the body is so good at dealing with very low doses, if"},{"startTime":3287.015,"endTime":3291.505,"body":"you can minimize the amount of dose, the chance of harm are substantially reduced."},{"startTime":3291.565,"endTime":3295.585,"body":"And may well, for practical purposes, for long-term harm, be close to zero."},{"startTime":3295.655,"endTime":3299.185,"body":"Whereas if there's very high dose, then the risks obviously are much greater."},{"startTime":3299.245,"endTime":3304.716,"body":"So reducing the doses are the key expect, except for those in the immediate vicinity"},{"startTime":3304.716,"endTime":3306.905,"body":"of radiological nuclear or chemical incidents."},{"startTime":3307.295,"endTime":3314.692,"body":"It's possible, uh, very substantially to reduce the dose by taking relatively simple measures, generally"},{"startTime":3314.692,"endTime":3316.665,"body":"at very low doses."},{"startTime":3317.005,"endTime":3321.025,"body":"The health effects are small and, uh, temporary."},{"startTime":3321.605,"endTime":3326.798,"body":"Uh, and even for, um, moderate doses, the body is remarkably good at recovering from"},{"startTime":3326.798,"endTime":3327.145,"body":"things."},{"startTime":3327.145,"endTime":3331.305,"body":"It's, it's got extraordinary regenerative, uh, capacity for radiation."},{"startTime":3331.765,"endTime":3338.1,"body":"Uh, get inside, stay inside and decontaminate if you are outside in the, uh, under"},{"startTime":3338.1,"endTime":3338.945,"body":"the plume."},{"startTime":3339.885,"endTime":3345.807,"body":"And for chemicals, rapid removal of contaminated clothes, further decontamination with copious showering, and then"},{"startTime":3345.807,"endTime":3350.545,"body":"seeking medical care, uh, are the best ways to minimize the risk."},{"startTime":3350.545,"endTime":3353.585,"body":"This is gonna cause any long-term, uh, medical harm."},{"startTime":3354.235,"endTime":3355.025,"body":"Thank you very much."}]}