Too far? Okay well today's topic is cancer risk of radiation, specifically to people who work in the nuclear field. The blog title credit comes from our class lecture Feb 5 when we watched the clip of "Fat Man and Little Boy" when John Cusack, playing fictional scientist Michal Merriman, performs a criticality experiment to measure how a plutonium source behaves in the early stages of a nuclear bomb detonation. He's holding two things that aren't supposed to touch apart with a flat blade screwdriver, turns out this was a bad idea when the screwdriver slips, they two halves to this sphere come together and the experiment goes wildly out of control, irradiating him and the others in the room, him dying of radiation poisoning 9 days later and the other surviving. This was a real situation with a real core, nicknamed "The Demon Core" (Professional Wikipedia Source) and it was really held apart by a screwdriver, although the scientist killed was actually named Louis Slotin. This was the second person killed by this exact core, the first being another scientist, Harry K. Daghlian, Jr. exactly 9 months earlier.
All very interesting, but onto the real meat of this post and how that all relates to cancer risk. It's a stereotype that nuclear engineers or any other nuclear workers face that their job sucks or is terrible because they're going to get cancer from it, if they haven't already, and that nuclear things are terrible for the world because: cancer. Most of this is caused by innocent ignorance of the topic, less than 1% of the US population will ever operate or work on a nuclear project, and most of what the public hears is bad news about accidents or what prominent people say about nuclear energy, see my last blog post about media and nuclear accidents or my friend's post to start on what relevant US figures might say. Don't get me wrong, cancer is a very real risk when dealing with radioactivity, but an important caveat to this is that there is A LOT of effort that goes into protection of the workers and even MORE (10-100x lower limits) that the public is allowed to be exposed to.
To try to spark ideas, provide valuable topics /explanations, and expand the amount of readers I may have, I've decided to try to ask friends or family that have almost no nuclear experience besides knowing me if they have any immediate questions that pop up when I the next few weeks' blog topics. I came to this attempted direction when the blog came up while talking to a good friend of mine on deployment in the Army, the exact way I put it was, "do you have any questions about cancer risks and nuclear engineering sh*t." He asked what the average amount of exposure you would encounter across your career is and if it is detrimental to your long term health. Well, here comes the part the media would quote: It depends based on what you do relating to nuclear, reactor repair, operation, national lab experimentation, etc but it is limited to 5 rem/year and yes, it can be detrimental.
Next, the part the media may not quote. 10 CFR Part 20, Title 10 (Energy) of the Code of Federal Regulations, Part 20 deals with radiation exposure of workers and public as well as monitoring, controlling, and dissemination of such information to the public and workers. For the year 2013, 135,681 people were monitored, 57,115 of which received a measurable dose. The average dose per person was 0.15 rem.
This value can be compared with the 0.31 rem that the average person in the United States receives annually from natural background radiation. Worldwide annual exposures to natural background radiation are generally expected to be in the range of 0.1 rem to 1.3 rems, with 0.24 rem being the current average worldwide value (right from 10 CFR 20's Radiation Exposure Information and Reporting System, REIRS, from 2013).
So, the average is 0.15 rem added onto the 0.31 rem you receive every year from stuff like the sun, bananas, and radon gas leaking out of the ground. Take this with a grain of salt, remember it varies by what actual job you do, but the average is an okay number to use for this purpose. Like skin cancer from the sun, sometimes you get it and you weren't even in the sun for long and sometimes you get it after you've burnt yourself crispy more than enough times. Cancer sort of follows this trend for other nuclear exposures as well: if you get some dose, you can develop it and you can be reasonably sure that if it does, it'll be in the area affected by what you were exposed to. It is a stochastic radiation effect; cancer's probabilistic, it is random in nature. We only know that increased radiation exposure has led to increases in cancer rates from post accident or WWII analysis. We know that the radiation might penetrate your skin, depending on what type it is. We know that it might interact with your skin or any other tissue/bone/organ it passes through. We know that it might damage a piece of the DNA contained in the cells in that body part. We know that depending on that body part's replication rate, it may not matter for some cancer but for other radiation sickness effects, more frequent replications mean worse consequences from the jacked up cells being replicated. We know cancerous cells tend to go haywire and replicate much faster and that their real problem is they make tumors that may spread and do internal damage to the body from blockage or random lumps of cells tearing things or pressing on things that shouldn't be pressed on.
If you subscribe to hormesis, you believe that some level of radiation is actually good for things because we're developed in an environment with low levels of background radiation for so long. This is a fact, we have lived some level of background radiations the entire lifetime of the earth. However, the effects (good or bad) of this background radiation are unknown. Hormesis theorizes that it is not very small, long term doses that harm you but rather larger doses in smaller time frames. To finally answer my friend's question, my average exposure at a power plant would be approximately 1.5 times that of any normal person, but well within levels where it should be negligible. The NRC regulations are very conservative limits, and I will receive much less than the max limit. Yes, this may affect me long term by increasing my risk for cancer, but this is also assumed negligible because of low levels. Taking into account I will have less radiation exposure to myself from radon, bananas, and the sun on a submarine, I'll probably have much less total dose per year than an average person and thus actually have less cancer risk.
I'll end here before I go on forever. If you're interested in more, look up the USS Ronald Reagan crew exposure after their humanitarian aid to Fukushima or passing on radiation induced genetic deformations to offspring. Next week brings radon and lung cancer risks, radiation protection standards, and atmospheric dispersion of radionuclides!
-Michael
So, the average is 0.15 rem added onto the 0.31 rem you receive every year from stuff like the sun, bananas, and radon gas leaking out of the ground. Take this with a grain of salt, remember it varies by what actual job you do, but the average is an okay number to use for this purpose. Like skin cancer from the sun, sometimes you get it and you weren't even in the sun for long and sometimes you get it after you've burnt yourself crispy more than enough times. Cancer sort of follows this trend for other nuclear exposures as well: if you get some dose, you can develop it and you can be reasonably sure that if it does, it'll be in the area affected by what you were exposed to. It is a stochastic radiation effect; cancer's probabilistic, it is random in nature. We only know that increased radiation exposure has led to increases in cancer rates from post accident or WWII analysis. We know that the radiation might penetrate your skin, depending on what type it is. We know that it might interact with your skin or any other tissue/bone/organ it passes through. We know that it might damage a piece of the DNA contained in the cells in that body part. We know that depending on that body part's replication rate, it may not matter for some cancer but for other radiation sickness effects, more frequent replications mean worse consequences from the jacked up cells being replicated. We know cancerous cells tend to go haywire and replicate much faster and that their real problem is they make tumors that may spread and do internal damage to the body from blockage or random lumps of cells tearing things or pressing on things that shouldn't be pressed on.
If you subscribe to hormesis, you believe that some level of radiation is actually good for things because we're developed in an environment with low levels of background radiation for so long. This is a fact, we have lived some level of background radiations the entire lifetime of the earth. However, the effects (good or bad) of this background radiation are unknown. Hormesis theorizes that it is not very small, long term doses that harm you but rather larger doses in smaller time frames. To finally answer my friend's question, my average exposure at a power plant would be approximately 1.5 times that of any normal person, but well within levels where it should be negligible. The NRC regulations are very conservative limits, and I will receive much less than the max limit. Yes, this may affect me long term by increasing my risk for cancer, but this is also assumed negligible because of low levels. Taking into account I will have less radiation exposure to myself from radon, bananas, and the sun on a submarine, I'll probably have much less total dose per year than an average person and thus actually have less cancer risk.
I'll end here before I go on forever. If you're interested in more, look up the USS Ronald Reagan crew exposure after their humanitarian aid to Fukushima or passing on radiation induced genetic deformations to offspring. Next week brings radon and lung cancer risks, radiation protection standards, and atmospheric dispersion of radionuclides!
-Michael
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