Hello, I'm Erin Duffy. I'm a board certified occupational environmental medicine physician. I am excited to talk with you today about radiation health. I have about two decades experience working in the Navy with service members and civilians who've been exposed to radiation parts of their job, taking care of them to prevent radiation injuries. And I'm happy to say I've been successful during that time and not seen any adverse outcomes. However, being prepared for radiation health emergencies and radiation sickness is something that I applaud you for pursuing. And I hope you learn some information from this lecture today. Our goals and objectives include being able to identify various sources of radiation exposure understanding the types of ionizing radiation and non-ionizing radiation. Being able to explain the basic principles of radiation physics and why it's important to construct dose estimates. Understand the biologic effects of ionizing radiation on the human body and recognize the acute radiation syndrome when it occurs. Identify metabolic effects of ionizing radiation and utilize therapeutic strategies in such exposures. This is a picture of myself in Hiroshima. I currently live in Japan and I visited here a few months ago. This is what they call the atomic dome structure. It was a municipal building, a large municipal building in Hiroshima. And that at the time of the bombing was being primarily used by Department of Defense personnel there. When it was fairly close to the epicenter and lots of other buildings surrounding it were completely damaged down to the ground and rubble. But it did remain and it's still there as a landmark. I felt slightly strange as an American tourist going there and being a tourist observer, but a local gentleman was very excited about my shirt, really insistent on taking this picture. And I'm happy to share it with you today. And also the story of reconciliation between U.S. and Japan is really one to be applauded. I'd like to give special thanks not only to these victims from whom we have learned so much, but also previous presenters on this topic, Dr. Eckstein and Dr. Edens, and the various resources I've utilized in this lecture, which I've listed here. All right. As with everything in occupational medicine, really the exposure is something that we have to think about from the very beginning. How much and how bad and where is it coming from? So with that in mind, I'd like you to take out your pencils and for a couple seconds here, think about where radiation occurs in the workplace and maybe in the general public in this world. Okay, so I imagine most of you, because we started with the picture of Hiroshima, did think about nuclear weapons, and that is a potential source, and it does remain one that we are concerned about. But on a more frequent basis, we worry about the workers who are building, preparing, storing nuclear weapons and their exposures. Along with nuclear weapons factories, of course, we have nuclear power plants. And these are perhaps the fortunate byproducts of the science that went into studying the weaponry. While we think of nuclear reactors as being things like the ones just seen in Oak Ridge, Tennessee, there are plenty that are actually mobile. All of submarines these days are powered by nuclear energy, and there's two reactors on every aircraft carrier. These don't pose risk just for service members, but also for the civilian workforce who repairs and takes care of these machines. Closer to home for you, we worry about transportation of nuclear waste, nuclear medicine products, all sorts of different radioactive materials. These could cause big localized problems if there should be a crash of such a vehicle. Now we're healthcare workers, and so x-ray probably popped straight to your mind as an example, the classic example of radiation since it was the first discovered. And CT machines, which have significantly more radiation exposure than an x-ray machine. We now monitor how much radiation somebody gets over the course of their life with patients. We try to estimate that particularly younger children who get repeated CT scans, it can add up and cause them problems in the future. Nuclear medicine is still a growing field, both for diagnostic purposes and for treatment purposes. And the nuclear medicine is using materials that need to be shipped and stored and handled properly as well. So it is a different type of exposure than the radiation itself, and then x-ray radiation. Okay, museums. Did you think of museums and universities? But they do a lot of testing and experimentation with radiation, both for medical purposes, but also for document dating and, you know, in the archaeology, so doing carbon dating is something we do there. In the farming and agriculture industry, there is radiation of the food. If you look at this picture on the right hand side, you'll see the gross looking strawberries, and those are what are truly natural. And those ones on the left have been irradiated, and will last for weeks in your refrigerator without going bad. So everybody thinks, ooh, what kind of chemical are they using to make these last? And it's really not a chemical, they're irradiated, which causes death to the germs, and whether that's bacteria or the fungi. And they're able to last. Here in Japan, it's not that common. I get a strawberry and it'll last three days. Also, in those plants that I was showing before, they have ones that irradiate insects. This causes them to be sterile, and then these insects are released by the millions into the environment. Sounds sort of crazy, but this is the process for protecting crops, because they reproduce with wild mates, and then nobody has any offspring related to that. They prevent more millions of bugs being born. So this is a way to really control the insects that affect the crops. My son is a lifeguard, so I constantly worry about his sun exposure. Sun does cause radiation, of course, and you get more of it the closer you are, because our atmosphere does help to blend it out. Pilots and aircrew have more cosmic radiation over the year than a lot of other people. Obviously, astronauts are going to be at more extreme risk of cosmic radiation exposure, and those that are present for months on the International Space Station are ones that we truly need to be concerned about. On the other end of the Earth, or inside the Earth, we deal with radiation coming from our soil. Radon is the primary one we worry about, but of course, mining is where you go to find uranium and the other elements that you need in order to have nuclear reactions. This is my neighborhood growing up in Connecticut. We're right along a fault line, I guess, of sorts that is full of radon. People who live in nice, tight, closed houses that are good for keeping the heat in will also keep the radon in, and volumes might be very high in the basement. That's a lot of radiation exposure. There is some exposure with smoking cigarettes. The primary carcinogens in cigarettes is not the radiation exposure, but the chemicals. However, they do add up together. And cemeteries. Some of our cemeteries that are older, highly densely populated, I don't know if that's the right word, do qualify almost to the level of a nuclear waste dump site. Radiation due to human decay is truly a factor. That's why the carbon dating works, and we also have that with humans. Even living beings radiate to some extent. We do know that people who are sleeping next to somebody else every night, you know, married people tend to live longer, and yet they are being constantly exposed to low levels of radiation. These are my two cats, Yuki and Jack. Okay, so give yourself a star for all of these that you caught today and thought about. The one that I didn't have a picture for, logging, transmission, and density gauges, that is something that we do see industrial accidents happen with, usually with using either the gauges or the industrial x-ray machines when unsealed sources are left and people get exposed to them. Some other small things that people don't consider, different weather monitoring systems, and even smoke detectors emit some radiation on a constant basis. Okay, but dose is the poison, right? And so what are the levels to worry about, and where are the cutoffs that you need to treat or to remove somebody from the workplace, or to remove somebody from the workplace, things like that. All right, the OSHA does not actually have the, set the PELs for radiation exposure. Instead, you have the National Council on Radiation Protection, and OSHA just sort of copy forwards them, but that's good. We have the experts working on it. Let's start with the average exposure in the U.S. in a person per year. This is my daughter here, incidentally not in, well, she's in the U.S. now at Mount Holyoke College, but this was taken in Okinawa. So how much radiation would she get in a given year? And if you caught that from the prior slide, good on you. It's 360 millirem. All right, let's talk about the opposite end of this spectrum. What is radiation's LD5060? What is LD5060? It's your lethal dose at which 50% of the population would die without treatment within 60 days. So what is the LD5060? And if you said, well, it's probably the other end of this list, you were right. So 400 rem, but usually we discuss this as rads or grays. So 400 rads or 4 grays. Okay, why do we have all these different terms? Rem, rad, gray. Let's take a pause from discussing levels and discuss these units of measurement. So first of all, how radioactive a substance is, is measured in terms of how many disintegrations of that atom happen per time. And so if you have, you know, one disintegration per second, that's called a becquerel in the international discussion, right? The US, just like we still use inches and Fahrenheit, we're doing our own thing. So we still, we pay tribute to Marie Curie and continue to use Curies. And one Curie is 37 gigabecquerels. This is all very difficult to correlate between the two. But luckily, we as doctors don't really need to use this very often, except to have an understanding of how radioactive a substance might be. And this came about in a real life example, in 2001, in the country of Georgia, a town called Leah, where three wood gatherers went out into the forest with December, and they were collecting firewood. It's a couple day trip where they go out with their wagon and select a lot of wood and bring it back. And they travel, you know, deep into the forest and off the path in order to find wood for this purpose. Found in addition to their wood, a two canisters about the size of loaves of bread, sitting on the ground with the snow all melted around them. One of the woodcutters went and picked that up and burned him, it was hot, and he dropped it. And this is weird, right? But this is a multi day excursion for them. And so they were planning on camping out. So let's at least use these canisters to keep warm tonight. And so they set them up with a fire, a campfire and the two canisters and sort of a triangular formation and the three guys slept within that. They did end up getting radiation sickness later on. And once these canisters were found by the scientists was found to have over 1000 tetra becquerels. So a huge amount of radioactivity. Now, how much is being emitted by anything, any given entity doesn't matter as much as how much you take in, right? So these, these canisters had actually been sitting there for presumably over a decade, since they were tracked back to a hydroelectric plant from the USSR that had been shut down. And we know that that plant had eight such canisters, by the way, two of them remain unfound to this day. So, but these canisters weren't really doing any significant harm to anybody until these gentlemen encountered them. And so that is where we discuss the absorbed dose. So how much of the radiation got into that body? And this is by units of energy into how much material so 100 herbs of energy into one gram or one joule into one kilogram. These nicely relate better to each other, the USA and international one where gray is 100 times a rad, we use rads and grays for large doses. And for deterministic purposes, I will come back to that later why that's important. As for our three patients, patient three is actually the guy who picked up the first canister. Once bitten twice shy, he's the one who slept closest to the fire, while the other two slept close to the canisters overnight. So in terms of doing the dose reconstruction later to figure out how much radiation these gentlemen were exposed to, the ones who had further were further away from the unit, but for a longer period of time ended up with a higher doses. Now, going back to our list of how much exposure is normal and is allowed, we discussed REM, right? REM or the international equivalent sievert are very similar to rads and grays, but there is a quality weighting factor that's added to that. And so to really to understand it a little bit more about the potential risk to the body, this is used when we are dealing with smaller doses of radiation, when we're setting regulatory limits and for stochastic purposes. So again, the US uses millirems or REMs for regulation, and they will use either rads or grays when talking about big exposures, because in medicine, we sometimes use metric. The stochastic concerns are the smaller amounts, that background of 300 or 360 millirems, and deterministic concerns are when we're dealing with large doses, and we know that they're definitely going to cause some sort of outcome in disease. A little bit more here, stochastic has to do with increased exposure, meaning increased risk. So you have a risk of getting cancer when you're exposed to more radiation you're exposed to, the more your risk goes up. Whereas a deterministic is the more you're exposed to, the sicker you're going to get. So the more sun you sit out in the sun for a long time, the worse your sunburn is going to be, and the higher your chance of skin cancer, right? You're not guaranteed to get skin cancer. With deterministic effects, there's usually a threshold below which you will not have any medical issues. With stochastic effects, you don't really know. When you're down that low, it becomes very difficult to get good scientific studies that let us know you would need huge populations to look at in order to really be sure is at these very low levels, does it increase risk or not? For protective purposes, we go that there's no safe level, that any amount of radiation exposure does start to increase your risk. There are theories of thought that that could not be the case. Again, the picture of the cats and the fact that people who sleep together tend to have lower illness rates. Is there some protective benefit to low doses of radiation? Perhaps it helps to destroy the bad cells that would have caused cancer otherwise, maybe. But for setting regulation and in general, we want to have zero exposure if possible. This is a nice pictorial helping to demonstrate what's going on in the biological level when dealing with stochastic and deterministic. The damage comes in from the radiation to the DNA. And nicely, a lot of times, the body repairs it and you go about your life. That's great. Sometimes that repair fails, the cell dies. And if this happens to a lot of cells, then you are suddenly dealing with the effects that are deterministic actual symptoms. If the DNA is repaired, but incompletely or improperly, then you end up with mutations. And that's what moves ahead to cause cancer or hereditary effects. All right. So, you learned nothing else today. This slide is it. What is the occupational exposure limit per year? All right. You did see it in an earlier slide, but I didn't foot stomp it. Now I'm foot stomping it. Yes, 5 rem. All right. But 5 rem is not the only thing. I do have OSHA just as a pictorial to help you remember that this is the occupational exposure limit. but as I said before, this is actually set by the National Regulatory Committee. So they have a 100 millirem exposure to general public rule as well. So if you are out measuring, I've got gentlemen who work in a, using industrial radiography are measuring for any cracks in an aircraft, right? And they're doing that at the same time that somebody's bringing their school kids around to come have a tour of the facility where they're kept, right? The hangar. So these kids are walking around in the non-roped-off area. They can be exposed to up to 100 millirem, okay? And so how much can the general public be exposed to if they are in the vicinity? But for the workers, it's five rems a year. And ALARA. ALARA is as low as reasonably achievable. And this has to do directly with what we just talked about in the stochastic, very low dose effects. Is there any safe amount of radiation? We don't think so. So as low as reasonably achievable. All right. So five rem is the occupational exposure limit per year. What is it per quarter? And you said, Dr. Duffy, please, this is like second grade math, maybe fourth grade math. Yes. Okay. It's 1.5, 1.25 rem, which is five divided by four, because there's four quarters in a year. And yes, ALARA. Okay. Yeah, that's, you know, makes sense. But for most other exposures, we have a eight hour time weighted average, we might have a yearly exposure. With radiation, it is required that you have no more than 1.25 per quarter. So you can't get all five rems of radiation in one period of time. The reason behind that is because how we are best protected from radiation are these three items here. And I want you to walk away remembering time, distance, shielding, time, distance, shielding. This is how to protect people from radiation. Reduce the amount of time that they're exposed, increase the distance, and use shielding. With the time, it has to do with how much damage the body can take to their DNA all at once, and either, you know, not repair it or repair it poorly. So if you have a small, if you have an exposure of say 10, right, and, and then two seconds later, you have another exposure of 10, you don't have time to repair from the first one. But if it's time to repair, and then you have the next exposure, you are going to really be starting from ground zero again. Right. All right. This picture here shows an accident that's not a radiological accident, but imagine if it were. And then some of the responders, a tribute to the responders in Chernobyl. So there are special exposure limits in disaster scenarios. Here they are. For a cleanup response, it would be 10 REM. This is per year, but you have to factor in this is going to happen over a fairly short period of time, especially the 25 REM, the life saving and critical infrastructure response. The picture of the fire, that should be a 10 REM type of event, you can divert the traffic, close that down to the fire goes out, you know, there's nobody left to save at this point. And then you send in the cleanup crews. You can rotate people so that they are in there for shorter periods of time. And that will help to keep everybody's exposure down. And that's the key thing when trying to keep exposures down when trying to keep exposures down during disaster scenarios is having many workers, but each only working for a short period of time. Also, if you're dealing with volunteers, you might want to consider things such as somebody who's not pregnant, right? The older somebody is, the less likely they're going to have significant stochastic effects because it takes time for cancer to grow. However, the older somebody is, the more sensitive they are to radiation syndromes. So keep that in mind as well. All right, and what is the exposure limit for a fetus? And if you are thinking it's got to be the smallest amount on this list, you can still give yourself credit. That is the recommendation of the international agencies in charge of radiation limits, but they don't set them. They only make recommendations. The current requirement is 500 milliremps. There were a couple other items on this list, and you might wonder why I included those markers. 50 rem is the exposure that you can get to a single extremity. If you're dealing with a beam of radiation, then sometimes we do see workers getting exposures to their hands particularly. That might be quite significant, but they're not going to cause them to have whole body effects. They're not going to get acute radiation syndrome, and it would be unlikely to have systemic cancer effects related to those. 15 rem for the eye might be a bit, you know, not so protective. I would keep that smaller, but that's the regulatory limit. All right, don't be scared about this, and somebody out there is laughing, and they majored in physics, and they're not scared at all, but most of us are like, this is not my area of expertise. I don't remember any of this. Well, we will give you just the basics. Okay, ionizing radiation deals with ions, right? But the ion is not something of a concern. Ions are just molecules that have a charge. They're either net positive or net negative, and you love them on your potato chips, right? Salts are just full of ions. All it is is you've got a positive and a negative that are hanging out together and tasting good. So, ions are not in the of themselves bad, but what we worry about is the energy that is used to make an ion, right? That is what radiation is. So, it's an energy that can be either in a waveform or a particle form, but it's strong enough to create an ion in matter. When it's in a particle form, it's basically a piece of another atom that is broken off and is shooting through the air or shooting through material and brings that energy with it. And then waveforms are an energy that we're more familiar with, right? And so, similar to light, and you can find these on the electromagnetic spectrum, and that's where x-rays and gamma rays are. This is a beautiful pictorial. This is one from the Japanese website I was talking about that shows how these different radiations, where they come from. So, the electromagnetic waves do emanate out of atoms, and it's where they come from that makes a difference. X-rays are generated outside of the nucleus, whereas gamma rays come from inside the nucleus. Other than that, they basically work similarly in principle. Now, the particles are little bits of the atom speeding around. Alpha particles are fairly common. They are essentially the nucleus of a helium atom. So, they have two protons and two neutrons. They're a bit big and chunky, which we'll come to later, and you can see why they are not super penetrating. Beta particles have a negative charge to them. And then neutron beams, they're also particles, but they're called beams because they really just, they can penetrate everything. And these are created in nuclear reactors. So, let's return to talking about electromagnetic radiation, and there is this spectrum. We will, at the end of this lecture, discuss non-ionizing radiation, but remember that the shorter wavelengths, X-rays and gamma rays, are waves, and those are the ones that can cause ionization. So, they are radioactive. Radioactive is the essence of a substance that can spontaneously disintegrate and emit radiation. So, think of that chunk of uranium that Marie Curie's looking at, right? Radiation itself is when it's absorbed by another body, and contamination is the presence of radioactive material somewhere where you don't want it to be. Now, a lot of times, things are not contaminated when they're irradiated. So, you get exposed to radiation when you're in a CAT scan or getting an X-ray, but there's no contamination. There's nothing left behind when you get up and leave that facility. So, you are not radioactive. You're not carrying anything with you that's radioactive, and you're no threat to anybody else. And that's important to remember when you're seeing patients also, is how were they exposed, and is contamination a concern or not? These are the Greek shorthand for our different types of particles and waves, and a bit more information here about the particles and waves. So, the particles, well, you can see here we have some big arrows and some thinner arrows, and the big arrows are showing how much have a high ionization density, which means that they are going to cause, once they're in your body, a little bit more of a problem than one that has a low ionization density per particle size. If you remember before, we talked about the quality factor or the weighting factor when we calculate rem and sievert, and how rads or grays are converted. That has to do with that high ionization density, or as your outline calls it, the linear energy transfer. I believe your outline emphasizes this a couple times, so I would suspect that maybe this is on the test. So, the ones with the bolder arrow here have the higher linear energy transfer. Those are the alpha particles and the neutron beams or neutron particles, and they, because of that, their rem is going to be a little bit higher per rad. I'm sorry that this came out blurry once I enlarged it, but I wanted to show you how penetrating these different items are. The particles, alpha and beta, are not very penetrating at all. Alpha frequently stops with clothes or pieces of paper. It can't get through it. Remember, that's the largest one. It's fairly bulky, and it'll just fall off. Beta typically does not penetrate very deeply in the skin and is more likely to cause burns and cutaneous radiation syndrome. X-rays and gamma rays are more penetrating, and neutrons, although also particles, are the most penetrating, and these are the ones that, for the reason we have lots of water surrounding the nuclear rods to keep them safe. Again, I'm reminding you of time, distance, and shielding. This has to do with the shielding and why we use lead, of course, in the x-ray department. Okay, biologic effects. This is the part you've been waiting for because you're doctors, right? All right. Lapse of time after exposure and effects. There's almost no time between when the radiation cuts through the body and causes the damage at the cellular level, so the DNA is damaged immediately, but it takes some time for that damage to show up and reveal itself. So if you have damaged DNA, the cell doesn't die just automatically, but it can no longer make the proteins that are necessary for the lysosomes to do their job, and so the cell gets poisoned and it dies, right? It takes a little while. You are going to see the effects in cells that rapidly divide much faster, right? Because now, damaged DNA that can't divide and can't grow and make a second, you know, further on daughter cells is going to have a problem. So you will see the deterministic effects, the tissue damage in the GI system and in the bone marrow primarily, okay? The other parts though, the damage that gets partially repaired, your mutations, that can happen whether or not you have deterministic effects, right? So if you have deterministic effects, you're also having mutations. So people who have acute radiation syndrome will still be at risk for cancer and hereditary effects down the road, and people who have small amounts of radiation exposure that don't reveal any deterministic effects will also have the stochastic effects, but just a lower risk. Again, stochastic deals with risk, deterministic reveals a disease. Stochastic causes cancer, and when it affects the egg cells and sperm cells, it can lead to hereditary defects. The deterministic, we talked about apoptosis, we talked about necrosis at dying, but also accelerated apoptosis happens, and then leading to acute radiation syndrome. Fetal effects are considered deterministic effects because the developing fetus, when it gets tissue damage, the same as a full grown human, it's a tissue damage, and so it's still considered deterministic. All right, another number to remember, one gray, 100 rad. This is the level at which you worry about acute radiation syndrome. Acute radiation syndrome is really a predictable series of signs and symptoms that progress in a standardized way over a period from a few hours to several weeks, and the timeline is completely related to the amount of exposure. We know about acute radiation syndrome, obviously, from the atomic bomb survivors, but also from various reactor and accelerator accidents, and even from some patients who've had side effects of therapeutic irradiation. Please remember that we said four grays, 400 rads, is around the lethal dose for 50% of people. The some people will do well better than that, some people less well, but following the damage that the hemopoietic system sustains will tell you the most. For acute radiation syndrome, there is a prodrome, a latent period, and a manifest period. In our woodcutters, who are hanging out that night with their nice warm canisters and fire, they sat around and talked about what could make these canisters so hot, and they shared their vodka. They noticed that their vodka made them sicker than usual, faster than usual, and they all went to bed early because they were feeling so gross from the vodka. It wasn't from the vodka. They woke up fairly early in the night because they were still feeling gross, and took off. That shortened the time that they were exposed to these canisters, but they noticed they were sick that day. One patient too was still sick the next day and he had diarrhea and he went to see his doctor who diagnosed him with intoxication, thought he was drunk and gave him an IV and some vitamins. This is just about textbook prodrome. It usually starts within hours of exposure. At a very high exposure, it can be within minutes. It might take up to two days. It usually lasts a few hours and maybe up to two days. The most common symptoms are anorexia, nausea, and vomiting. Diarrhea shows a worse likelihood of outcome because it potentiates a higher exposure and ataxia and confusion certainly have the worst prognosis. After this prodrome period, which is fairly brief and a lot of people won't seek care, two of these patients did not seek care. It will go on for a few days, weeks, just feeling fine. In our gentleman, one of them had a rash or I think two of them had a rash in the interim also, but it really wasn't until three weeks later on December 22nd that one of them had severe fatigue and also was noticing that his back was a terrible rash on his back that was scaling off. The types of radiation syndrome are divided into three different types, hematopoietic, gastrointestinal, and neurovascular. They have to do with the signs and symptoms both in the prodrome period and then in the manifest disease. And so you won't see anything different in the hematopoietic and the gastrointestinal other than perhaps the level of pancytopenia. You may not see red cells go down in the hematopoietic level. And with gastrointestinal, you should see diarrhea that you shouldn't see in the lesser involved one. Neurovascular is you're going to have the same nausea and vomiting, you'll have diarrhea, but also the ataxia, confusion, and almost likely like this will lead to death. Obviously you see on this list, the deep ulceration, necrosis, that's not really acute radiation syndrome. So these three are the types that they talk about for ARS. That last one is more cutaneous radiation syndrome, or it's sort of sudden death if it were to occur to the whole body. Even in people who have very mild radiation syndrome, very mild nausea might not have significant effects. If you follow them closely, you'll see the evidence that it has affected them as early as their prodromal period. The most obvious one is the lymphocyte count. That gets affected rapidly, and it doesn't recover for many weeks or years. Measuring it every eight hours for the first two to three days is usually extraordinarily helpful in calculating what size dose they had if you need to create a dose estimation. So dose estimation helps you to determine, does this person need transplants? Does this person need higher level of care? If a person has a injury in the workplace, there's usually a radiation health physicist involved who can help figure this out for you, how much dose did they get. But in cases like these gentlemen, where they show up with the symptoms first and you don't know that it was radiation, the clinical evidence can help to lead to the dose estimation. Okay, with manifest disease, fatigue and GI symptoms are the primary things that everybody sees. However, what ends up being the most damaging will be the bone marrow depression, because it is going to lead to infections, to fever and malaise. You will see hair loss just from the manifest disease, and that can be related to or completely independent of cutaneous radiation syndrome. So as I mentioned before, there's the three acute radiation syndromes. Cutaneous is its own entity and can occur with any of these or without. In our woodcutters, they all three had cutaneous radiation syndrome. The one who picked it up had it on his hands and the other two ended up with it on their backs. And one of they all recovered from their acute radiation syndrome, but one of them died related to his cutaneous. It just required too much grafting, recurrent infections, and he was not able to survive after about a year and a half of attempted care. Here's an example of some pictures from somebody who had the skin injury related to acute doses of radiation. And the levels that you see here, how much exposure you can get, you can get higher levels of exposure when you're dealing with an extremity than when you're dealing with the whole body. Why is there an LD50? You know, and some people do better and some people don't. That's life, right? But the human variables tend to be age, older age, you're going to do worse. And trauma. This is something we know from the blasts in the past. If you sustain a trauma and you have radiation illness, your survivability goes down drastically. What part of the body, how much of the body, the dose of the radiation, all of these things are variables that will help to determine the outcome, as well as the protective factors, how much time, shielding, and distance. Of course, those really go into the dose. They're very, these are interrelated. When you are doing your HPI, make sure that you get this information in detail. How long was somebody there? You know, what time did they check the clock when they entered? Did they know when they left? How close were they? And really, you know, have them try to use measures of, I was from here to the EKG machine, and then you measure that and put that in your notes. What were you wearing? What was it made out of? Somebody was wearing jeans and a puffy overcoat versus wearing a rayon shirt. These things matter. With acute radiation syndrome, it's going to end one of two ways, either death or recovery. It's going to go on a while. But the fatigue may last a long time. But if they are able to be supported through that period of bone marrow suppression and GI loss, you know, loss of their mucosa, then they can make it. Unfortunately, there are outcomes that will last for many years. You can see the stochastic effects, carcinogenesis, the prenatal effects, genetic effects, those things, their risk for those will go up. But there are also deterministic effects that will last to cataracts, radiodermatitis. And we do see, you know, kind of irrespective of the cancer that they do tend to live shorter lives than their peers. OK. When we discuss radiation, there's a lot of the workplace accidents will involve one or two people. But dispersal events are something that we have a big concern for, for those of us who sit around and think about chem-bio warfare and other types of tragedies. So remember, there's a radiation exposure, and this is primarily what you see with workplace injuries. But there could also be a radiation exposure device or an RED. REDs are used by malicious personnel to place perhaps under a subway seat and expose everybody who's in that subway gets an exposure or to take out a certain individual. They're usually stationary. They're emitting radiation without any contamination involved. Because there is no contamination, people who suffer from exposure to radiation this way are no threat to the health care workers. You need to reassure your workplace personnel of that. Contamination, on the other hand, does involve dust, debris, radioactive elements of some sort being on the people, on the patients who are involved. This would be in the event of a nuclear fallout situation, whether that's from a power plant or from a bomb. The most likely scenario, however, would be from a radioactive dispersal device, an RDD. These are what terrorists may use in addition to a bomb to emit radioactive material around a city and cause panic, massive panic, is what I wanted to say. So the radioactive dispersal device will likely be made from nuclear medicine materials or industrial radiography materials that have been stolen from a construction site and added to this bomb. It will likely not be significantly high in the radiation exposure, but will cause a lot of panic and scare people from the emergency room to the general public. When you have these, because the radioactive material is likely not life threatening, you need to perform your critical emergency care and triage really quickly and fast and do that before decon. Look to determine who needs care, who needs life-saving interventions, and then provide those life-saving interventions. Here's a pictogram from the Oak Ridge people talking about a radiation incident. Is there a life-threatening problem? Yes, then you stabilize, you fix that. Don't worry so much about the radiation. Remember time, distance and shielding, move, change out different people, make sure that you have some PPE on. And, you know, and they're also time has already elapsed by the time they got to the ER. So the amount of radioactive material on them has gone down. So if there is no external exposure, if there is no contamination, so you're going down the green pathway, and all they got was external exposure, keep taking care of them like we talked about. Bring them into the ER, monitor their CBC, take care of them symptomatically. If there is contamination, we have the purple one, which is external contamination, and the yellow, which is internal. Yellow internal contamination only is a very unusual type of thing, but it can happen in an assassination attempt. So somebody is injected or given a, you know, a drink that has radioactive material in it. So now they have it inside them without any on them. They are a very minor threat to the healthcare workers, depending on the amount that they have inside their body. And again, you can rotate your workers frequently and consult your radiation health physicist at your hospital about these. But the purple ones, the ones who have contamination on their outside, are the ones that you're most likely to see after an RDD event. So the first thing to do with them is really try to set up a controlled area, get your decon system going as early as possible, and remove their clothing. Remember, time distance shielding, get that material off, reduce the amount of time they're being exposed to it. Right. Assess and treat any emergency conditions that they have, and then quickly use the monitoring equipment that your hospital has to determine what type of radiation type they have. So is it alpha, beta, or gamma? Do they have any wounds, body orifices? You know, what is contaminated? Collect some swabs from their mouth and nares, and quickly then move along to decontamination. It's important to collect that ID material before decon so that we can do the dose estimate, but you don't want to delay too much. After you've done decon, you should do a whole body survey. These are done fairly slowly, and it will help to determine if the person has been fully cleared or not. Just a reminder on the external communication, you're going to have lots of things competing for the same time period. You want to do decon, you want to triage, you want to do emergency critical care, and you want to identify what the contaminant was. But first and foremost, get their clothes off, put those in a bag, and then using your best judgment, move from there. Ideally, you want to collect swabs before deconning, but if you can't, you can't, and usually somebody at the scene is going to get plenty of radioactive fallout to figure out what the contaminants are anyways. All right, look at that little picture of the stuff going in the bag. Again, that is perhaps the most important. On number three, it does remember with the final release survey, number five there is saying turn them over and do it, you know, do the log rolls so that you can look at their back also, do not forget about cleaning their back. Internal contamination, we mentioned how that could be by injection in a assassination attempt, and could be ingestion, and then inhalation during an RDD event. So the dust is exploding in the air, people inhale it, and now they have beta particles and alpha particles inside their lungs. These will cause higher risk of problems down the road because you can't decon these in the same way you can decon external contamination. For these patients, make sure, of course, like with the others, you do the history, you get the face swabs, and then 48 to 24 hours, you want to be collecting that urine and feces. That'll help you to do bioassays on them and figure out those reconstructions. All right, a welder comes to the ER because his boss said to. He's feeling fine, a 46-year-old guy, he smokes, he has stage one hypertension, and some arthritis. Yesterday, he was called urgently to a food irradiation facility after a tornado came by and damaged the facility. There was a loose fitting above the cobalt 60 source, and it was leaking higher levels of radiation than it should have. He wore a rubber suit and dosimeter while he was performing the repairs. He does not typically work with radiation. He tells you he feels fine, and the physicist from the food processing plant is accompanying him and says that he thinks that he got 25 rem. Okay, what's 25 rem? That, if you remember, was the cutoff for the life-saving critical infrastructure level that somebody could be exposed to in a given year, right? So, he's gotten this over the course of one day. All right, his physical exam is unremarkable except for a slightly high blood pressure. All right, this is what we would call limited exposure. So, he, you know, generally, 100 rem or less is more exposure than we want somebody to have, but they're unlikely to have any type of, you know, events occur related to this. They're not going to show you much, laboratory tests are probably not going to show you anything either. You might see a slight decrease in lymphocyte count, but mostly the laboratory tests are going to be reassuring. What you are going to want to talk to them about is potential late effects and how this could have damaged some of their DNA. If somebody's pregnant, it's a much more difficult conversation, obviously, but it's also a good time to talk about other things in their life that they can do to reduce their risk of cancer and to improve their health. For this particular person, he's 46, so has he had his colonoscopy? He is smoking. You might want to associate how much exposure he had, similar to his smoking, and that's something you can look up online, but it would probably be about three packs of cigarettes would cause the same amount of cancer risk as the exposure that he just had. Scenario two, an engineer is doing a building inspection of a building that's being built right now. She finds equipment left behind by an industrial radiographer. She picks it up and is examining it. She doesn't know what it is. It looks like sort of a magic wand. There's other various pieces of equipment. She lets the foreman know that somebody left all this stuff down in the basement. The next night, she gets a phone call saying, hey, this was some radioactive material. You should go to the ER. When she shows up, she's obviously scared. Her heart rate's elevated. She says she has some mild nausea. What would you do for her? Well, obviously a pregnancy test, right? Then what's this nausea? Is this from her being sick? Is this from her being nervous? Well, you'd want to get that great exposure and get somebody from the workplace to let you know what was the radiation source? How strong was it? Get information from her. How long did she hold it for? How long was she in the room that it was in? Things like that. What was the position and distance? Was she working in the same room, squatting in the corner, doing something somewhere else? It was her left side that was exposed to this the whole time, and she only noticed it on the way out. What happened? Next, you want to have a really good record of time to the onset of vomiting, right? When did she start to feel nauseous? When is the first time she vomited? This is extraordinarily informative about how much dose that they probably had. You'll also want to start following that CBC, looking at it every eight hours. Then you can use charts that are online to help you calculate how much is the lymphocyte count going down by day, and that will help you reconstruct the dose. The gold standard for using biologic information to reconstruct the dose would be to take cytogenetic studies and use dicentric chromosome counting. So a dicentric chromosome, such as you see there labeled D, is a chromosome that now has two centromeres in it, and so it has multiple crosses points. This happens naturally to some extent, but you'll see increased counts of it when somebody has had radiation exposure. This will happen within the next day or two after the event, and it'll stay stable for many weeks. So if somebody presents late and you are concerned that maybe this was an exposure and you missed the prodromal period, and now they're in the manifest stage, this is an excellent study to take. There are opportunities to gather this and evaluate it either in your own facility, or you can upload it to other places, and they can do the counting, or you can send it. If you can get it to Oak Ridge within 24 hours is their preference. It should be collected in lithium tubes are the preference, and then kept at room temperature, and do not spin it down. People should be hospitalized if they've had more than two grays. If they've had more than three grays, you want to get them to a tertiary care center. This had a lethal dose, super lethal dose, or a little bit less than we have here. 50 grays is enormous, but 25 grays in an elderly person or somebody with other disease, or they also have trauma, they probably don't need to be transported because it's not going to make any difference. This person is going to die. In that case, you want to give supportive care, antiemetics, pain relievers, certainly having the chaplain or mental health people there to discuss this with them. For people who are expected to live, they should also get all those three things, but additionally, antibiotics, absolutely. If they can tolerate it PO, then PO regimens, and you want broad spectrums. Antifungals and antivirals, we certainly see candida and herpes flare pretty pronounced in people with acute radiation syndrome. As discussed before, baron marrow suppression is the number one killer in people with acute radiation syndrome. Managing that is of critical importance. Unfortunately, marrow transplants have not been super beneficial. Obviously, you'll be discussing this with people who have a bit more experience in making this determination. In a lot of cases, either they're rejected or the infection rates are just still so high that they haven't been beneficial. The growth factors, neupogen, certainly are very effective, particularly if they're given early, as early as the prodromal or early latent phases, then they make a significant difference. With internal contamination, you want to try to eliminate it as fast as possible. There are specific antidotes for difference, but it's all very dependent on what element you've been exposed to. In general, for internal contamination, you'd want to call Oak Ridge and talk to them about what to do. If a lot of people think potassium iodide is the solution, however, it's really only for radioactive iodide and it only protects the thyroid. It's not significantly making the huge difference that we would hope it would based on movies we watched in the 1980s, I suppose. Cutaneous radiation syndrome, so the burns such as our woodcutters sustained to their back, these are going to take a few weeks to reveal themselves, first with a dry and then wet dust formation. But once they show, they truly need advanced wound care and hyperbaric oxygen. There are bioengineered artificial skin regimens from France and Japan that aren't fully approved in the U.S., but you would like to get them to a tertiary burn center where they can get the best, most advanced care as possible. A lot of times, the cutaneous radiation syndrome, when it appears early, looks like an allergic rash. So giving antihistamines and various topicals at that time is what people will do if they don't recognize that it's a radiation caused event, but are probably beneficial if you do recognize it as well. All right, 27-year-old baseball player coming back from a national, you know, it's right before the World Series, so they just had the pennant playoff and he's having vomiting and diarrhea. He tells you that the entire team actually has food poisoning, something bad happened when they ate at their away game. People are always saying it's food poisoning, right? Saying things are food poisoning when they come to the ER. If it is food poisoning and they tell you multiple people are sick, your first call should be to your public health command. Don't call it a command, but the county, right? Call the county. If there's an event that's involving multiple people, you want to take that seriously in terms of investigating what was the true cause, right? Is this food poisoning that they all had or because they're a famous baseball team? Was it a terrorist event and there was some kind of R.E.D. placed on their bus? All right, this is the dirty bomb scenario. So a dirty bomb goes off at the airport. News reports are saying that there's radioactive material in it. All right, you're going to call in people to set up your decontents, but you know what's going to happen first? Taxis, Good Samaritans, people are going to jump in their cars and get there before the ambulances. This we know from incidents such as the Las Vegas bombing. Most people are going to arrive by POV, personally operated vehicles, not by ambulance, and they're going to get there as fast as they can. So they're going to be on your doorstep. Think about that. How? What are you going to do to take care of them? And how are you going to triage them? And remember, time distance shielding. You can get them out of their clothes. They're already away from the event. The radiation exposure is much less. Bringing people out of the hospital to start taking care of them on the grounds is not a bad idea. Okay, the news reporter calls you and says, should we give everybody potassium iodide? What else should we tell the public? If you do get this call, and this could be a great test question, do we give potassium iodide after this event? Most likely no. You got to find out what the contaminant is. If it is a nuclear plant meltdown type of thing, then they might say the whole community should get it, right? But most important is the time distance shielding. So you want to tell people stay indoors, turn off your ventilation, okay? Just wait. I know everybody's nervous. People want to know what's going on. I want to drive and go get some potassium and protect myself. No, stay where you are. Stay indoors. Keep your doors shut. If the weather supports it, turn off the ventilation and wait until the experts tell us that it's safe to move. All right, now a little bit about non-ionizing radiation. After talking about radiation, this is almost nothing to be worried about, right? So this is radiation that will cause a molecule to vibrate, to move. It gives it some energy, but it's not going to ionize it or change it chemically. You have five basic types. Solar, lasers, microwaves, low frequency, and extremely low frequency. Lasers are actually a different type of solar radiation. So I would not say that there's five basic types, but this is how your outline has it. Closest to the radioactive part of the spectrum is the ultraviolet light. So ultraviolet light is within the 200 to 400 nanometer range. And you can think about the black light that everybody dances at, and that's fine, up to the germicidal UVC range. And that is more damaging. Luckily, we don't get too much UVC here on earth because of our ozone layer, and that ozone layer helps to protect us. So this would be more of an occupational exposure if somebody is getting UVC exposure. UVA and UVB come with natural light, and they cause the things that you know that they cause, right? Photokeratitis, cataracts, sunburns. You can also get photosensitization reactions. So that makes you more sensitive in the future to get exposure to sun will cause itching, scaling, and potentially pain. The visible spectrum of light is the one that you're used to seeing every day. The blue range is the range that's up again closer to the ultraviolet, which is closest to the radiation. So that is the one that we are the most concerned about causing retinal injury, particularly when the lens in your eye is focusing it on the back of your retina. Infrared radiation is on the other side of the visible spectrum. Here it's infrared, think of the reds causing you to be warm. Here we start getting some heat created by this type of radiation. It can still cause sunburn, but it's more the heat part that's causing some damage. It causes very little damage, to be honest. LASERS, I don't know if anyone remembers that LASERS is actually an acronym for Light Amplification by Stimulated Emission of Radiation. It's essentially a single color, a single wavelength of energy that's focused into a beam, right? It depends on which level of light it is. It can be anywhere from ultraviolet to infrared and all of the visual spectrum. The eye is the most sensitive area because the lens and the cornea do focus that onto a small area. Also, it does mention down here the airborne contaminants. A lot that we see in the medical industry, such as getting rid of tattoos and facial beautification things that people know to protect the eyes, but it might also be important to the workers in these regions to wear appropriate N95s because you are getting little pieces of biomaterial up into the air. Microwaves and radio frequencies, these are beyond the infrared. They are fairly long wavelengths, but they do produce increased temperatures. That should be rather evident, that's why we use a microwave. It's most likely not going to cause any problems, but the deeper tissues, if you want to reduce your risk, always just step away a couple of feet from the microwave and you're not at risk. Long way. The extremely low frequency, so radio waves particularly, there is some epidemiologic evidence out there to suggest that these very low frequency radiations are related to cancers, particularly in children, childhood leukemias. There's not enough for us to be regulating this, but for patients who are concerned, reducing exposure is probably not going to harm them and can only be good. Again, I want to thank those who contributed to slides for this and to the information that we as a society have, particularly those who are victims of radiation mishaps. The phone number for Oak Ridge REACTS Institute is there. I encourage you to put that into your cell phone and then you will have it available should you ever be in a need to consult these people. They're available 24 7. That concludes my presentation. I really appreciate you affording this time for this. I would value any feedback that you have, particularly after your test, if there were certain areas that were not covered and I can improve how for future people who take this exam and training. Have a great day.

radiation health

occupational exposure

ionizing radiation

acute radiation syndrome

radiation physics

dose estimates

nuclear medicine

ALARA

radiation emergencies

non-ionizing radiation

Dr. Erin Duffy