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 
Thanks for this! I can send it to my relatives in CA and tell them to stop freaking out. For all the mistakes people have been pointing out, I think the main point is nuclear power is safer than the media has led us to believe, and that the Fukushima power plant incident is nowhere near the level of danger that the Chernobyl accident was.
What we should be worrying about in California is a possible major earthquake striking here!
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(No need to post this.)
Thanks for the chart. FYI, note “of of” in the second line of the intro.
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Thanks for making this chart! I just developed a zooming version on Prezi here: http://prezi.com/jo4rdj2ed08i/xkcd-radiation-dose-chart/
While I personally like your poster version better, it seemed like an interesting challenge to make a Prezi version.
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User Friendly has a comic on the same subject: http://ars.userfriendly.org/cartoons/?id=20110319
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What you have just done, Randall Munroe, you have delved into junk science. All the data that you have used to create those charts comes from, well, let us think about this. Who monitors radiation data? Governments and the Nuclear industry. You have actually created a chart based on, what is essentially, junk science.
This is damaging. What you have just done, oh my god, it’s the top post on the reddit front page right now. Redditors are happy, and justified in thinking that there is nothing wrong with a ‘little radiation’. As far as government monitoring, and nuclear industry monitoring goes… Chernobyl wasn’t so bad after a week. Of course Japan isn’t either. As a matter of fact, the WHO stated that only 50 deaths were directly attributed to Chernobyl.
Directly.
Watch this. http://inmotion.magnumphotos.com/essay/chernobyl
I don’t care why you created that graph. I’ve never disagreed with you before. But what you just did is sick, wrong, and I don’t care if you did it to placate the masses or if you actually believe what you created. It’s false, it placates the masses, and it makes me sick.
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Dear Randal, I translated the chart into Japanese. Would you give me permission to either repost it, or have you place it at xkcd? I believe the chart adds much needed perspective on terms most people in Japan don’t even understand. In this case, the units of measurements, and what they mean in comparison to each others.
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Kevin, for Chernobyl in 2010: 6 mSv/h * 24h * 365 days = 52,5 Sv yearly, which is obviously a lot. I don’t think Randall’s intent was to be misleading, but I agree that calculating radiation dosage for the long term would make the chart more complete.
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Kevin Peltola, sorry but you are wrong. There are many people with no link to government or the nuclear industry that monitor and study radiation and its effects.
You may want to check the fit of you tin foil hat and get your lithium prescription renewed.
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Kevin:
I believe that what Munroe’s very useful chart shows is the effect of ionizing radiation itself. (Alpha, beta, gamma, UV, and x-rays.)
The effects of Chernobyl, while terrible, are the result from ingesting radioactive materials, actual fissionable atoms, which then lodge in the body and irradiate the cells around them. This is a radically different thing from simple exposure to radiation. (Not to mention that some of the elements are poisonous aside from their radioactivity.)
Chernobyl involved the explosion of a graphite core reactor, spewing core materials in the form of dust, smoke, and gas over the countryside, and it is this, not simply radiation, that is responsible for the effects seen in the photo essay you link to.
The degree to which this happened at Fukushima is as yet undetermined, but it is far, far below Chernobyl, and consists mostly of byproducts with short half-lives (minutes to days). As far as I know, no actual fuel was released at Fukushima.
There is in fact nothing wrong with “a little radiation”, which is good because its unavoidable and has been since long before the nuclear age. It is not even possible to avoid some contamination with radioactive isotopes such as carbon-14 which form naturally.
Munroe’s chart is reasonably accurate as far as it goes. If there is junk science here, it is your irresponsible hysteria.
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So the deadly power of bananas does not originate in their radioactivity, interesting. Thank you, you saved me a lot of pointless research.
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Thanks for this chart^^… I live 60km south-ish from the nulcear plant in question, and it was getting increasingly difficult to convince my family that I was safe from any harmful doses of radiation where I was… (having since moved to Tokyo to stay with friends while I wait for the city to repair the water pipes, and tsunami/earthquake related damage)
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Finally some context!
Of all the news programs, news sites and so on reporting, you and Ellen the the only people who seems to have put any of this into a context that’s meaningful!
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Thanks for this. One suggestion – add a line of text up top (around the intro) saying how many microSieverts in a milliSievert and how many milliSieverts in a Sievert – basic info to help set context but it’s currently buried in the chart.
Also, while the references to early levels at/near Fukushima can be helpful context, that info is highly perishable as well as dependent on what has or hasn’t been publicly reported. Not sure how you could deal with that without repeatedly updating the chart but at the least I’d suggest another line up top giving the date at which the data are current and a caveat about limitations on that data.
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Also, have a look at this grim picture, with deaths/kWh. Fossil truly kills.
http://www-958.ibm.com/software/data/cognos/manyeyes/visualizations/2e5d4dcc4fb511e0ae0c000255111976/comments/2e70ae944fb511e0ae0c000255111976
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Best reporting on Fukushima I’ve seen to date is by this fellow who says “I’ve never been more ashamed of my profession.” And unlike the major media, these e-zine folks include their sources (too).
http://search.theregister.co.uk/?author=Lewis%20Page
Someday we will get over our fear of the dark, and fear of glowing in the dark (just like we did of gasoline, which kilogram for kilogram has twice the energy as our best chemical high explosive).
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Isn’t something wrong with the Chernobyl 2010 data in the chart?
Your source (http://blog.vornaskotti.com/2010/07/15/into-the-zone-chernobyl-pripyat/)
states that you get about 5-6 micro-Sieverts per hour in front of the plant (about the same as flying in an airplane), however the chart says thet you get 6 mili-Sieverts per hour instead of micro-Sieverts.
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A technical note on Munroe’s excellent chart:
It lists radiation Sieverts, a measure of energy as absorbed by living tissue, with units of Joules/Kilogram. (There is are different weighting factors for specific types of tissue, such as skin, liver, kidney, etc., or, as in this case, an integrated whole-body value.)
The terrible consequences of Chernobyl were due to contamination by radioisotopes, atoms of radioactive elements. This is measured in Becquerels, “the activity of a quantity of radioactive material in which one nucleus decays per second”. It has units of 1/second.
——————
Two quotes:
View From the Porch:
———
And then this, an excerpt from one of Roger Zelazny’s lesser known short stories.
(The protagonist is he who is known to this world as Prometheus.)
[Transcribed by me, from The Doors of His Face, The Lamps of His Mouth, “Love Is an Imaginary Number”, p. 342, ibooks, 2001, New York]
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I sense that Kevin shall not be back to back up any of the nonsense he just spouted.
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qseal00: “I sense that Kevin shall not be back to back up any of the nonsense he just spouted.”
Exactly. “Escaped into another Place.”
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excuse me but what is “normal background radiation”? I don’t understand it ? Like it’s far higher than spending a year in a brick house, and far lower than a year next to chernobyl, is it the yearly average for everyone on earth?
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Esurnir says: “…what is ‘normal background radiation’? ”
It is the radiation you receive from naturally occurring sources, such as cosmic rays, and other pervasive sources. It’s a tiny fraction higher these days than before the Manhattan Project, but still well within the ability of our bodies to tolerate it.
It is measured at specific locations, and is given in Sieverts, counts per second, or similar units. It does not refer to contamination.
———
Brace yourself, Munroe. You’ve just been Instalanched.
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Kevin,
Just dissing scientific evidence is a great way to start a conspiracy theory and a great way to be very wrong. If you have real conflicting evidence, show it, don’t just bleat about how people have conspired to fool us all, when that is just your sceptical guess.
The latest scientific evidence, not just Kevin-style hype, suggests that low-level radiation is somewhat less harmful than first thought. The original safety levels were set too high as a precaution before the real long-term harm was understood. Now long-term studies are beginning to report that low-level exposure is less harmful than first assumed.
I used the phrase ‘suggests’ above because that is how science really works: there is no absolute truth, just an ever-refined view of the world.
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In 1978, scientists found that being downwind of a coal plant meant additional exposure of about 20 microsieverts a year.
It’s pretty hard to find good numbers about radioactive exposure from coal plants more recently — the radioactivity in the air should be going down because of the scrubbing, but the radioactivity in the coal ash would be going up.
Similarly not sure what the numbers are from hydrofracking.
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Randal,
I humbly suggest you add figured for a backscatter X-ray scan at the airport into the chart. Enquiring minds want to know.
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Heh… I have a lesser lifetime radiation dose growing up within 10 miles of TMI than my FH who has only lived in brick houses. Over-reaction much?
(For what it’s worth the 6th graders in a near by school district used to take field trips to TMI before 9-11. We really weren’t concerned.)
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Would be good if you could augment the chart to include examples related to the current “panic”, like how much radiation per day you get in California due to the radiation blowing over from Japan. Or maybe a separate chart with a map showing different number of colored squares showing how much radiation you’re getting from stuff blowing over. People need to stop freaking out and realize that buying iodized salt won’t protect you even if there was a serious level of radiation.
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Just find it quite funny that eating a banana inflict more radiation on you than sleeping with someone LOLOL…
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This is not the relevant chart for this situation. Make a chart of ingested, integrated contamination into the body, with the expected 0.04% increase in cancer deaths per REM of chronic exposure (and situation where one would get that. Each colored square could be 1 or 10 dead people per 10,000 above normal. Or for more excitement, incidence of cancer whether non-fatal or fatal. You’ve only made a chart of what we call “shine”, external source.
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Hi,
Would it be possible to purchase prints of this?
Thanks,
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The sky will fall, though only one brick at a time. We still have time to sing in the sunshine, but, ah, there’s the children. Well, by the time they get around to cursing us we’ll already be dead.
Strange fate, that let’s us off the hook: not having to watch our children suffer. No wonder that I no longer believe in Hell.
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I was surprised to see the TSA’s full-body screening systems didn’t make the list … until I saw the reports of how much radiation it exposes us to.
Note, to compare with this chart, both TSA and NPR state that a standard chest x-ray is 100 µSv rather than this chart’s 20 µSv. NPR puts a mammogram at 700 µSv while this chart measures it as 3000 µSv.
The stated radiation from these backscatter scanners is 0.05 µSv (TSA, reported as 0.005 mrem) to 0.2 µSv (UCSF via NPR) per usage. UCSF suggests that measuring this radiation on the skin would result in a larger value. The TSA report includes a disclaimer that they are re-testing these numbers and should have results around the end of this month.
The real danger with respect to the backscatter scanners was to the TSA workers (who had zero protection) and others who work in airports. Fortunately, these machines are not in use any more, though that might change if the TSA releases a new report that doesn’t increase those numbers.
http://www.tsa.gov/research/reading/xray_screening_technology_safety_reports.shtm
http://www.npr.org/templates/story/story.php?storyId=126833083
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It is a fact that cell phones do not cause cancer as a consequence of ionizing radiation. I think it’s VERY unscientific to flatly say that anything doesn’t cause cancer at all. At the most, cell phones are not known to cause cancer.
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