There’s a lot of discussion of radiation from the Fukushima plants, along with comparisons to Three Mile Island and Chernobyl. Radiation levels are often described as “<X> times the normal level” or “<Y>% over the legal limit,” which can be pretty confusing.
Ellen, a friend of mine who’s a student at Reed and Senior Reactor Operator at the Reed Research Reactor, has been spending the last few days answering questions about radiation dosage virtually nonstop (I’ve actually seen her interrupt them with “brb, reactor”). She suggested a chart might help put different amounts of radiation into perspective, and so with her help, I put one together. She also made one of her own; it has fewer colors, but contains more information about what radiation exposure consists of and how it affects the body.
I’m not an expert in radiation and I’m sure I’ve got a lot of mistakes in here, but there’s so much wild misinformation out there that I figured a broad comparison of different types of dosages might be good anyway. I don’t include too much about the Fukushima reactor because the situation seems to be changing by the hour, but I hope the chart provides some helpful context.
(Click to view full)
Note that there are different types of ionizing radiation; the “sievert” unit quantifies the degree to which each type (gamma rays, alpha particles, etc) affects the body. You can learn more from my sources list. If you’re looking for expert updates on the nuclear situation, try the MIT NSE Hub. Ellen’s page on radiation is here.
Lastly, remember that while there’s a lot of focus on possible worst-case scenarios involving the nuclear plants, the tsunami was an actual disaster that’s already killed thousands. Hundreds of thousands more, including my best friend from college, are in shelters with limited access to basic supplies and almost no ability to contact the outside world. If you’re not sure how to help, Google’s Japan Crisis Resource page is a good place to start.
Edit: For people who asked about Japanese translations or other types of reprinting: you may republish this image anywhere without any sort of restriction; I place it in the public domain. I just suggest that you make sure to include a clear translation of the disclaimer that the author is not an expert, and that anyone potentially affected by Fukushima should always defer to the directives of regional health authorities.
xkcd 
I have converted chart and links to pdf file for anybody that wants to print.
can be downloaded here:
Click to access radiationinfo.pdf
(click on or copy url in to your browser)
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You forgot one thing: The basement. Basements are notorious for radon problems.
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Elizabeth, you sound like you know enough about this stuff to also know that “radiation hormesis” is a minority opinion, largely promoted by the nuclear industry. I know of no independent researchers who go along with it.
Thank you for identifying yourself as being involved with the nuclear industry (“having dealt with [NRC] inspections”).
I do not accuse you nor others among the rank-and-file of the nuclear industry of deceit. But you are doing something you believe in, and are subject to “observer bias.” (And I reserve the right to accuse those at the top of deceit.)
There is a large body of peer-reviewed work going back to 1953, beginning with epidemiologist Alice Steward, whose studies contrasted sharply with “official” numbers of cancers of nuclear workers. These progress through the pioneering work of Ernest Sternglass, who was subjected to a smear campaign with no actual peer-reviewed rebuttal. Then statistical studies from Gofman and Tamplin clearly show the lack of a “threshold effect,” and in fact show a hyperbolic relationship between dose and exposure at low levels — proportionately more health affect at low levels than at high ones.
The problem is that no one can prove anything. That is a HUGE problem, because whenever yet another statistical study correlates cancer with low-level radiation, everyone from the NRC to the FDA claim there’s not enough proof. What they REALLY mean is that, were they to validate these studies, they’d have to shut the nuclear industry down, and no one wants that.
I agree that coal fired plants also release a lot of radiation, and similarly, no one is really willing to examine that.
I’m not saying “shut everything down so we’re all shivering in the dark.” But the public deserves an informed choice. If people realized that the “blue boxes” on this chart represent exposure levels that, statistically speaking, WILL result in more cancer, perhaps they’d decide to do with less electricity. Or not, but the public is not getting the entire story from neither the industry, nor the supposed regulators.
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Jan, that just doesn’t make sense to me as a biologist. We are constantly exposed to low levels of radiation in the natural environment. Ergo, we should have adaptations to deal with it. We are rarely exposed to high levels of radiation in the environment, so we should not expect to have adaptations to deal with that. So why would the more commonly encountered level be the most harmful. Not saying it couldn’t happen, mind you, just that it would be odd.
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This will affect everyone the same pollution that travels by air and by sea, remember that there are air currents coming from all continents in a few days during the 2nd World War Japan managed to send bombs to the U.S. that failed to explode but true arrived.
I do not think that is reporting the severity of asusnto that the developed are: ground nuclear general em life is weakened through this with the consequent increase in cancer among other diseases.
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Esto afectara a todos por igual esa contaminacion viaja por aire y por el mar, recordemos que existen corrientes de aire que llegan por todos los continentes en pocos dias, durante la 2da guerra mundial japon logro enviar bombas a EEUU que por cierto no estallaron pero si llegaron.
Creo que no se informa cual es la gravedad del asusnto por que los paises desarrolados tienen plnatas nucleares, la vida em general quedara mermada con esto con su consecuente aumento del cancer entre otras enfermedades.
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This chart is well and good but I think it muddies the difference between a yearly dose and obtaining that same dose in a few months or days. I am not familiar with how the body responds to radiation over time, whether low doses over time are less damaging than the same dose delivered all at once, but the prospect of receiving a cancer inducing dose in a month or so is chilling regardless.
Also, though sensationalism is likely affecting the news to a degree, if the reactor situation worsens then the already high doses will increase further still.
Finally, remember that for those living near the plants we are not talking about monthly or yearly doses but doses that will accrue over decades, lifetimes. These are the doses which are truly chilling. If doses remain as high in those area 50km NW then those areas will need to be evacuated.
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This interesting youTube video is where I learned the basics of the Sievert:
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a chest x ray is 0,68-1mSv.
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Would be good to add the dosage from a conventional airport x-ray scanner and a backscatter scanner. (Haven’t read through all the comments so sorry if someone else has already suggested this.)
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Very informative chart. It really makes you think, I never would have thought, that I’m being expose to radiation while eating a banana! But I guess @Mason is right, taking that much dose in just one week, or in a short time must be more dangerous.
Japan is in a hard place, and it is bad that the radiation gets in the air and other part of the world. But I don’t think, that it will travel that much, to reach America in a way, that it will really effect anything.
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Hi,
the chart is quite good for helping put things in perspective but the three things I took the time to research were very badly wrong. I have posted some detailed calculations that I invite you to check out at WUWT.
Your figure for self radiation by the body’s K-40 seems too big by a factor of seven.
The claim about sleeping next to someone really lacks credibility and the banana is probably exaggerated by a factor of about 350 times !!
I’ve posted detailed calculations and credible sources for numbers, I would invite you to check your sources and check your numbers.
Clearly , if you are out to educate on the risks you can’t have that scale of error in your information.
best regards.
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So… does anyone else feel like the mammograms are alarmingly high??
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SOMEONE’S WRONG ON THE INTERNET.
xkcd, that means you! 😉
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* Throws banana in trash *
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See this, and decide on the issue of environmental radioactivity: http://www.nsrl.ttu.edu/chornobyl/Default.htm
All the mammals studied around Chornobyl show that even being exposed to what for their species is a “lethal” dose of radiation each year, they are not showing significant chromosomal abnormalities, and are reproducing great. Dr Baker found that the human presence in their environment was far more damaging than the radioactive material from the accident.
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One pack of cigarettes is equivalent to one green square, or 20 uSv.
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I wish to thank you for this awesome infographic. This is a clear visualization of relation between radiation amount “taken” and danger for human life and health.
Thanks, again.
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@Elise: I don’t know; would you rather have a scan or fail to detect breast cancer?
There is definitely something to be said for weighing the risks of scans against the benefits and limiting them accordingly. It would also help put a damper on doctors doing procedures/scans that make more dollars than sense.
That said, one of the most interesting experiments we did in my intro physics lab was measuring background radiation, most of which came from the cinderblock walls. If everyone knew a little more about background radiation, we could have a much more intelligent dialogue about radiation risks. (As opposed to everyone in California going out and stocking up on iodine tablets….)
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Ken says: * Throws banana in trash *
If bananas were a problem we’d all have dies before we came down from the trees.
read my post with actual data and VALID refs before going bananas.
What needs to go in the trash is wiki-fukup-pedia and all the idiots (including the nuclear scientist who inspired and advised on this grpahic) who still seem to believe it is a valid source of information and don’t even bother to check.
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STOP THE CRAP !!!! Radiation is CUMULATIVE !!!
Patients had an average cumulative estimated effective radiation dose of 45.0 milliseiverts, with CT scans and nuclear medicine studies contributing the most radiation. Twelve percent of the sample population was estimated to have received 100 or more millisieverts of radiation, a value that exceeds the accepted threshold of safety for exposure to low level ionizing radiation. If study patients are representative of the general emergency department population, then a substantial number of people may be placed at increased risk of developing cancer over their lifetime from diagnostic imaging studies as a result of these exposures.
http://www.sciencedaily.com/releases/2008/05/080521093034.htm
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Am I reading this right? It’s impossible for the average person to meet the EPA limit of exposure to radiation based on average background radiation levels alone? Or is the EPA standard based on levels above background radiation, and if that’s true does the EPA keep records of background radiation levels for the entire country?
Also, I agree that the chart does make it difficult to consider chronic exposure versus acute exposure.
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It would be great if you’d add in a picture for radiation exposure from cigarettes. Roughly 20% of the US population still smokes, so this is something that is very easy to relate to. It might convince people that the brouhaha about the Japanese plants is overblown, or it might convince someone to quit smoking; win-win situation.
Tobacco absorbs radium as it grows. A 1965 study by the Harvard school of public health showed that smokers who died from lung cancer were getting 160 mSv per year to part of their lungs. The effective dose is estimated at 9.6 mSv per year. A 2008 study estimated that the annual effective dose for a average smoker is about 64 uSv. Smoking 1.5 packs a day is widely quoted to be 13 mSv. Note that the difference between effective dose and actual dose is a factor that is supposed to take into account the amount of your body that is exposed to the radiation – but for various reasons this doesn’t actually model what radiation in tobacco is doing very well, so be careful with effective dose when talking about cigarette-related exposure.
As a nuclear physics grad student, I’d personally suggest you go with the dose put forward by the book: Radiobiology for the Radiologist, Forth Edition; Eric Hall 1994. It’s not really meant as an anti-smoking propaganda piece, it’s meant as a specialist reference, so it avoids lots of appearance of bias. I think they quote cigarettes as being about 3.5 uSv each. A 2008 Gallup poll suggests that 12 cigarettes per day is the daily average among smokers (11 for those under 30, 15 for those over 30, 30% are under 30). That works out to 15 mSv for an average smoker in a year. As noted early, this is larger than other estimates given because it is not an effective dose, it is the actual radiation exposure.
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Beautiful diagram. Agree that some of this needs to be taken in context, but still an excellent tool to demonstrate radiation exposure. Best for people who are scared of an x-ray, but want the CT scan (yes, there are those). Or those scared of x-rays, but live in brick houses. Just wish you’d put the yearly dose the average interventional cardiologist gets from hitting the flouroscopy button too much.
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Someone asked about the ‘EPA yearly limit on radiation exposure to a member of the public’. The source is the NRC, the link is http://www.deq.idaho.gov/inl_oversight/radiation/radiation_guide.cfm, and the text is:
“(a) Each licensee shall conduct operations so that –
(1) The total effective dose equivalent to individual members of the public from the licensed operation does not exceed 0.1 rem (1 mSv) in a year, exclusive of the dose contributions from background radiation, from any administration the individual has received, from exposure to individuals administered radioactive material and released under § 35.75, from voluntary participation in medical research programs, and from the licensee’s disposal of radioactive material into sanitary sewerage in accordance with § 20.2003”
Note that this is NOT a total for ALL exposure for a single individual. This is a total for exposure to a single individual from a SINGLE SOURCE. It’s a limit on how much exposure your particular operation (nuclear plant, hospital radiology department, etc) can add for members of the general public who come into contact with it.
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quoted from Enosh: ”Am I reading this right? It’s impossible for the average person to meet the EPA limit of exposure to radiation based on average background radiation levels alone? Or is the EPA standard based on levels above background radiation, and if that’s true does the EPA keep records of background radiation levels for the entire country?”
In a nutshell, yes.
The EPA made up a number as a guideline that is relatively meaningless as a limit for members of the public. It’s supposed to be a high enough ceiling that you can get many medical scans without a lot of red tape, but still prevent you from getting exposed to small amounts of radiation willy-nilly. T
The more significant limit is the limit placed on occupational radiation workers. That’s supposed to be the upper limit of ”we’re pretty sure you won’t get cancer” with a large cushion – it’s considered very conservative.
The whole idea of the guidelines is called ALARA – as low as reasonably achievable. It means that, if you can do it without radiation, then you should do it without radiation. The low limit on radiation to members of the public also helps discourage some of the extreme stupidity that went on in the early 1900s up to the 1960s. When my mother was young, they used to give foot x-rays in shoe stores, for entertainment. In the early 1900s, con men used to sell irradiated water as a cure-all. Around 1917, a bunch of women died from painting watch hands with radium so that the watches would glow in the dark – the women would lick their paint brushes to keep the points fine. The guidelines about exposure to members of the public restricts this kind of nonsense, primarily. You won’t accidentally take a job painting radioactive material onto watches without knowing that you’re being exposed to radiation.
The EPA does not track background exposure to members of the public specifically. They make sure that the public isn’t allowed anywhere that they MIGHT be exposed to more radiation than the set public level. If the EPA was tracking your radiation exposure specifically, you’d know it – they track my levels. I work in a nuclear science facility, I wear a special monitoring badge when I’m in an area that might have radiation, and I get a letter every once in a while that tells me how much radiation I’ve been exposed to in the last year. They base the tracking on your social security number, and they assume you’re smart enough to wear your badge when you’ll be exposed to radiation at work. Interestingly, they specifically ask you not to wear the badge if you’re getting a dental x-ray or something similar – that’s tracked by the physician, who reports it with your social security number, and wearing a badge during the procedure would result in a double-count of radiation from the same source.
Think about it – it’s not like the government could tell you to stop going outside once you hit your yearly limit as a member of the public, or take away your cigarettes when you’ve smoked too much, after all.
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Please do not forget, that even for the Sv unit, it is only a statistical measure.
If, say, the base probability of cancer for you is p, every decay product you are hit by increases this probability by a tiny amount. That stays true even if you count redundancy in DNA, in cells and in active protection mechanisms in proteins. If the thing hits a weak spot, you are in for cancer.
We play dice every day. Admittedly the dice have many sides.
I generally tend to load my die in my favor (even if it costs me) and don’t like it when other people manipulate my dice in favor of “their purse” especially if its on the opposite of “my life”.
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I don’t understand this chart. Without a reference to River Tam or a comparison to the radion-accelerator core in Serenity, I am afraid it isn’t helpful.
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As so few above have found the ability to say it, i just want to say thanks for the trouble of constructing the chart. is very useful, and very well presented. any sensible person understands, without a ton of nit-picking, that there are lot of uncertainties in such matters and i dont see that the value of chart is in any way diminished by that fact.
thanks!
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Great graphic for those of us that need to help others understand.
Hillarious bananaphone reference BTW.
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What’s a bananaphone? Other than a joke?
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I can fill in a bit about how radiation and cancer risk work together; I’m going to try to keep down on the technical terms, since this really ought to be accessible to people other than fellow bio* types.
Radiation does help introduce new features to the genome–these could range from hemophilia to immunity to AIDS. These both are documented; the latter does not confer inability to be infected with HIV and is most present in those whose ancestors had the Black Plague. (For those specifically interested in cancer: you can get functional immunity to cancer via mutations–either in you or your ancestors–to the HLA region.) Between those two extremes are things that are relatively useless–immunity to smallpox, natural pink hair, red hair…those sorts of things.
Cancer itself requires that the DNA that gets altered is:
1. Within the genes coding for proteins involved in the cell’s life cycle.
2. It alters a section that is, well, Doing Something as opposed to Just Hanging Around. (For the more technically inclined: The mutation is not within an intron, nor alters the borders.)
3. The change actually does something Bad. The codons are redundant for a reason, and it’s quite possible for the mutated version to function just as well, or even better, than the wild type.
4. And last of all, in an individual whose immune system isn’t going to put out a hit on the cancerous cell.
Research is ongoing into a way to basically fix #4 for people who don’t have the genes against a given disease…
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Question:
There is a scare about wireless communications (WiFi, mobile phones) causing brain/testicle cancer and whatnot, which I particularly to not buy into.
How does this other kind of radiation compares to the nuclear power radiation in this chart?
Can it even be measured in sieverts, or is it too weak to even compute?
If sieverts somehow do not apply to wireless, why?
Is there other measurement unit which can correlate those different types of radiation then?
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