Talk:Banana equivalent dose/Archive 1

Banana equivalent dose
It would be helpful if all the figures in this article were also given in "banana equivalent dose"s. And perhaps there could be a table of some common sources of radiation and their activities in BEDs? xnn (talk) 16:09, 16 June 2010 (UTC)

Brazil nuts
The article states, "The most naturally radioactive food known are brazil nuts, with activity levels as high as 6600 picocuries per kg (1.875 BED)." Since one banana typically has a mass much less than 1 kg, I believe the listed banana equivalent dose would be incorrect. Unless I'm misunderstanding, one kilogram of Brazil nuts has the radioactivity of 1.875 kg of bananas. That'd be on the order of 15-20 bananas, so Brazil nuts would be 15-20 BED per kg. (Which admittedly isn't the unit being discussed by the article. Now I'm wondering whether the "other foods" section is really pertinent to this article in the first place.) --dzhim (talk) 03:24, 21 June 2010 (UTC)
 * While you have a valid point, it's important to remember that a BED is a concept, not a unit. Fell Gleaming talk 18:16, 25 June 2010 (UTC)


 * The article states, "A banana equivalent dose is a concept occasionally used by nuclear proponents[1][2] to place in scale the dangers of radiation by comparing exposures to the radiation generated by a common banana. [...] The banana equivalent dose is the radiation exposure received by eating a single banana [...] roughly 520 picocuries."
 * BED is a concept used to place a physical quantity in scale, and a BED has a defined (if imprecise) magnitude: I believe this meets the definition for a unit of measurement.
 * Anyway, if 1 kg of brazil nuts emits 6600 pCi radiation, and one banana emits 520 pCi, and a BED is the amount of radiation emitted by a single banana (not a kilogram of bananas), then the kilogram of nuts is 6600/520 ~= 13 BED, nowhere near the 1.875 BED stated in the article.
 * --dzhim (talk) 23:14, 6 September 2010 (UTC)
 * My point was simply in response to the suggestion that other foods may not be relevant to the article; they are, as the BED concept is wider than bananas per se. You certainly have a point about the figure being wrong; I imagine whoever put that in meant to compare them to an equivalent weight of bananas.  Fell Gleaming talk  00:05, 7 September 2010 (UTC)


 * Gotcha. I removed the BED number and rearranged and slightly reworded that section to hopefully make it a bit clearer.  I'm still not convinced that section is needed in this article, however (though I'm not outright opposed to it).  Does anyone ever talk about a "brazil nut equivalent dose" or a "potato equivalent dose," etc, (whether using a catchy term like that or not)?  If so, some such uses should be mentioned in the article, e.g.:
 * "Comparisons to radiation from other food sources are also common. For example, Bob Smith, arguing that a nuclear plant should be built in Podunk, East Dakota, claimed that the radiation to which Podunk residents would be exposed was 'no more than that from eating seven pounds of kidney beans per day.'[1]"
 * Or is it in practice overwhelmingly the banana equivalent dose, similarly to how economists talk about guns and butter but not chainsaws and cream cheese, even though, as an illustration of a model, the latter would work just as well? dzhim (talk) 03:38, 7 September 2010 (UTC)
 * Bananas are the one I commonly hear -- however, that usage is usually followed up with an explanation of radioactivity in other foods, to drive the concept home that it's not specific to bananas. Lima beans for instance are even more radioactive ... but there are quite a few people that simply refuse to eat them.  :)   Fell Gleaming talk  12:26, 7 September 2010 (UTC)

Additions to Iodine-K40 comparisons
This new text has several problems and inaccuracies:


 * It is uncited and appears to be OR|original research
 * K-40 is not just a beta emitter; it has a gamma mode as well.
 * I-131 is not just a gamma emitter; it also emits beta.
 * While I-131 does emit a higher ratio of gamma to beta than K-40, they are at a much lower energy level (364 kEV vs 1400 MEV)
 * The greater penetrating power of gamma radiation is irrelevant when the materials are biologically absorbed; The Q factor of Beta and Gamma are both 1.
 * Both Iodine and Potassium are biologically necessary elements.
 * While Iodine does bio-accumulate in the thyroid, thyroid cancers are among the most treatable. K-40 can cause a much wider variety of more serious and less treatable cancers.

I am thus removing it as unsalvageable. Fell Gleaming talk 14:32, 25 June 2010 (UTC)

Synthesis
Invoking WP:SYNTH for section The homeostatic objection. There is no external source provided, that synthesises the arguments in the way given in that section. WP:SYNTH makes WP:OR and deviation from WP:NPOV. Not allowed in Wikipedia. Rursus dixit. ( m bork3 !) 14:18, 6 September 2010 (UTC)
 * Synthesis is combining sources to reach a conclusion not expressed in any source. I think you have a point about the conclusion that the homeostatic object is false.  The facts themselves should merely be presented in that section.  I'm editing the section accordingly.  Fell Gleaming talk  15:33, 6 September 2010 (UTC)

"Risk of death"
According to the source, wouldn't the correct wording be "risk of death by cancer"? The way it is currently phrased does not make much sense without more concrete context, considering the risk of dying [without confining that risk to a certain time or cause] is already 100% for all living things. The section indirectly cited from the source (http://www.physics.isu.edu/radinf/risk.htm) reads as follows: "Another way of looking at risk, is to look at the Relative Risk of 1 in a million chances of dying of activities common to our society." Risk should maybe be better defined. --221.235.60.239 (talk) 11:52, 25 January 2011 (UTC)

Lead rewrite to improve sourcing and clarity.
This article said, "The equivalent dose for 365 bananas is 36 μSv (3.6 mrems)." This source was cited for support. The cited source quoted an earlier version of this article in support of that assertion, which is not a reliable source.

36 μSv for 365 bananas is about 0.1 μSv for each banana. At 100 rem per Sv, that is equivalent to 10 μrem, or 0.01 mrem, per banana. Explaining it this way, though, seems unnecessarily complicated.

Also, article said, "The average radioactivity is 130 Bq/kg (3 520 pCi/kg), or roughly 19.2 Bq (520 pCi) per 150 g banana.", citing a CRC handbook for support. I don't have the CRC handbook cited, but I see that this paper on Radiation Safety cited elsewhere in the article gives a figure of 370 pCi for a "medium sized" banana. That Radiation Safety paper goes on to say quite clearly that if a banana is eaten, the dose equivalent is 0.01 mrem, which it calls the "banana equivalent dose". I've changed the article to rely on the Radiation Safety paper for support of that figure.

I've removed mention of the CRC handbook. I don't think that WP:DUE requires its citation to be preserved in order to preserve mention of the different numbers of pCi per banana given by the two sources, as I think that difference is explainable by presuming that the two sources were discussing different sized bananas (i.e., a 150g banana vs. a "medium sized" banana). The 150 g banana is three bananas per pound, which seems to me more like a "large banana" size. The "medium size" banana would be about a quarter-pounder (2.2 lb/kg * 0.15 kg * 370/520 = 0.235 lb).

I googled around and found this source, which says, "12 bananas produces about 1 microsievert of radiation." That's 0.1 mrem from 12 bananas, or a bit less than .01 mrem from each banana.

I've rewritten the lead section to improve the sourcing and to clarify the explanation a bit (at least it is clearer to me than it used to be; hopefully I've improved it). I'm not a topic expert, though. If I've screwed this up, someone please correct it. Wtmitchell (talk) (earlier Boracay Bill) 05:46, 17 March 2011 (UTC)

450 g of potassium in ONE BANANA?
Uhm, guys, I'm not as wiki-savvy as I want to be, so I can't really change this myself, but 450g is about a pound. There most certainly is not a pound of potassium in an average banana. The figure you are looking for is 450mg, I believe, which requires a revision of the math. Could somebody please change this? 68.193.6.210 (talk) 06:10, 17 March 2011 (UTC)

clarify specifics of calculation
How does one calculate a banana equivalent dose specifically? Is it the radioactivity rate of an average mass of banana (perhaps adjusting for biological susceptibility), multiplied by the average amount of time for the material from an eaten banana to pass through a person's system (i.e., assuming that in the absence of any prior nutritional deficiency then the additional potassium will be excreted from the body in, what, about a day)? Or is it assuming that the potassium-40 from the banana will be entirely assimilated into the body and remain there until it all decays (or at least for many years)? It seems that there needs to be more discussion in the article of how we can estimate how much radiation dose is actually received into a person as a consequence of eating a banana (and not merely of how radioactive a fresh banana is while sitting in a crate).Cesiumfrog (talk) 00:02, 13 March 2011 (UTC)

This seemed a sensible place to put this. I just undid this Edit by [User:ClimateDragon]:
 * Because a normal, healthy person does not need any more potassium, most of it that is contained in a banana (radioactive or not) will be excreted after the usual transit of around 24 hours. During that time there will be some exposure but the dose will be orders of magnitude smaller than that given by the B.E.D idea.
 * The banana effective dose (BED) should not be taken too literally. It does not actually represent a dose you will get when eating a banana. It does show how much radiation occurs naturally.

Why? By definition, a BED is literally the radiation you will get by eating a banana. But yes, there is an issue with calculation when an actual value is attached. The assumptions made in the referenced articles are unstated and uncertain. The cited Wordpress article says:
 * Recall from my previous post that a banana contains about 10.92 Bq of radioactive K-40.
 * Run the numbers, and you find that the CEDE from eating one single banana is about 0.005 millirem.

I wish I knew exactly how he "ran the numbers"! The cited University of Nevada Environmental Health and Safety pdf, Radiation Safety says:
 * The amount of potassium-40 contained in a banana is 0.0528mg. This is equivalent to 14dps or 0.00037uCi. The dose equivalent, if a banana is eaten, is about 0.01 mrem.

And once again, there is a huge leap from a rate of decay events to a total biological dose per kg bodyweight. It's not that simple a calculation. You need to multiply the decay rate by the total energy per decay event (1332keV, if I'm reading this table correctly), then multiply by the total time of exposure in seconds, and (I think) divide by the mass of tissue exposed. You also have to multiply by a Quality factor, but since K40 radiation is all electrons and photons, that factor is 1. The time of exposure is pretty straightforward as ClimateDragon says. Most (almost all?) potassium ingested will be absorbed into the blood, but any excess will be excreted by the kidneys to maintain a very stable plasma concentration. I don't know about the mass of tissue exposed - is it just the whole body mass, or only the most exposed tissue? And if most radiation (beta decay) is in the gut and in the bladder, then should it be discounted for the radiation absorbed by the urine and gut contents? Anyway, using 8 hour exposure, 70kg body mass, and no discounting, I get a total exposure of about 10^-9 J/kg, or 1 nSv, or 0.01 mRem. 118.208.151.251 (talk) 12:44, 19 March 2011 (UTC)

Please state your full calculation. That seems to be what all the supposed sources of this idea are lacking. Also note that 1.3 Mev is the maximum beta energy, the average will be about half. Unlike gamma emissions, there is some billiard ball mechanics here and not all the available energy goes to the beta particle. —Preceding unsigned comment added by 95.176.126.166 (talk) 13:07, 19 March 2011 (UTC)

The wordpress article is blog content and should be removed. It is not a acceptable source and more to the point does not explain how he "runs the numbers" or what is the basis of his calculation.

The original source of BED seems to be the pdf you cite above. Sadly this also just makes an unqualified claim and gives no account of the basis of the calculation.

regards, ClimateDragon —Preceding unsigned comment added by 95.176.126.166 (talk) 13:04, 19 March 2011 (UTC)

14 Bq x 1.3/2 Mev/Bq x 1.6e-13 J/Mev / 70kg = 0.21e-13 J/kg/s Rad/s (=rem/s for beta)

8h=28800s

Dose = 6.048e-10 rem !!

Apart from the factor of two it seems we agree in principal, why is your result different? Please post you calcs. Climatedragon (talk) 13:36, 19 March 2011 (UTC)


 * I may have miscalculated, and will check. But regardless, your edit is inappropriate. You may disagree with the calculation of the value of a BED, but the specific concept of BED is indeed supposed to be taken literally. And unless you can cite a specific source for your claim as it stands, then it's original research. 118.208.151.251 (talk) 14:45, 19 March 2011 (UTC)


 * I did make a mistake in the previous post (a typo rather than a miscalc) - 1nSv is right, but that is 0.01 microrem, not millirem. I hadn't intended to give the impression that I agreed with the article's estimate of the value of a BED. Sorry about that. 118.208.151.251 (talk) 15:04, 19 March 2011 (UTC)

So when you have checked, we can see if we agree on numbers. The hps.org ref I provided in 6 states why this sort of approach to K-40 dose is wrong. Posing a request for figures and then deleting my content is wrong, especially when you don't even provide your own. Just the unsubstantiated result. Reverting my edits because of a claimed mid air collision is wrong.

The only solid ref for this whole topic is dubious because it does not state the basis or assumptions of the calculation.

You asked me to provide my figures and when I do you accuse me of WP-OR. Very funny.

Please stop your edit warring until you have established a point. — Preceding unsigned comment added by Climatedragon (talk • contribs) 15:13, 19 March 2011 (UTC)

PS Climatedragon (talk) 15:15, 19 March 2011 (UTC)

You also probably should consider how your position relates to the comparisons in the following section. Are you maintaining the K-40 in 200 bananas is equvialent of the ceasium-137 in Chernobyl muchrooms ?!

Think about it. Really. Climatedragon (talk) 15:23, 19 March 2011 (UTC)

My "position" (which you seem to have completely misunderstood) is not presented, because that's not what Wikipedia is for. It's not for presenting your "position", either. It's for presenting duly supported facts. I'll continue to remove your edit until you can present it in the appropriate way. 118.208.151.251 (talk) 15:32, 19 March 2011 (UTC)

So who put you in charge. This is sadly rather typical on WP and what makes of limited use as a reference.

I have provided a ref that shows this is inappropriate for K-40, you seem to skip over that fact. If you think it can be presented in a better way, I'm all ears. Climatedragon (talk) 15:44, 19 March 2011 (UTC)

Look, I agree with your point. You seem to skip over that fact! I don't agree with the way you're presenting it. I think that we should add a section in that goes through the specifics of calculations, or lack of them, rather than simply saying that a BED isn't supposed to be taken literally - clearly, it is intended to be taken literally. The problem is in the attributed value. 118.208.151.251 (talk) 15:49, 19 March 2011 (UTC)

Glad we basically agree. If you think such a section would be better go for it. I don't see that as a bad thing. What is a bad thing is presenting the only referenced value that is available in way that ignores that it is not applicable to potassium. I fact I have already provided a ref for.

I don't know whether the original author was being provocative or was simply totally ignorant of the biology. The ref'd paper is so trivial on its treatment it's hard to tell.

But this issue seems catch the imagination of a lot of people with a political stance on nuclear power so it seems important to put it in some factual biological context. If you can find better material with a well reasoned treatise I think what would be good and more productive than tit for tat editing.

I don't have anything better than showing the importance of the regulation of kalemie in the body why this BED idea is flawed. Climatedragon (talk) 16:50, 19 March 2011 (UTC)

Units
Unless the intent of this article is an ironic commentary on the plethora of units used in describing radiation doses (in which case it should sport a smilie, even though it is not very funny), it would be really helpful to have one unit (Sv?) used and put alongside each of the other uses.

Please ... quota (talk) 14:00, 17 March 2011 (UTC)


 * I just made this edit to the article in which, after an edit conflict, I effectively reverted some edits by User:Climatedragon. I've explained that somewhat on Climatedragon's talk page, and will expand on that here as it relates here.


 * Part of what Climatedragon's edits did was to try to clarify some of the differences between units of radiation and units of radiation dose equivalent, which is a problem with this article as it currently stands. There's a WP:hatnote in the Sievert article which appears to express concern over the same issue there (that article contains a link to this source, which supplies some clarification there). The hatnote there suggests a separate article which would explain this, suggesting Radiation levels as a name. I'll mention this discussion here on the talk page there (see Talk:Sievert).


 * I agree that explanation and clarification is needed, and that the topic is messy enough that a separate article should be devoted to the explanation. I also opine that it is a Bad Thing&#153; for several articles (this one, Sievert, probably others as well) to attempt separate explanations of this. I'm looking here for some expression of consensus that creating such a separate article is a good idea. The content I would envision for it would pretty much present information drawn from the two outside sourced I've linked above, and/or perhaps similar information from other sources.


 * Specifically regarding units of Radiation (e.g., Ci, Bq) and this article, I think that this article can and should avoid use of units other than ref and Sv (and subunits thereof, e.g., mrem, mSv).


 * Comments? Wtmitchell (talk) (earlier Boracay Bill) 04:24, 19 March 2011 (UTC)


 * Well, except that rem and sieverts aren't units of radiation I suppose that'd be fine. Charlie (Colorado) (talk) 06:18, 19 March 2011 (UTC)

Phrasing
This:


 * Because a normal, healthy person does not need any more potassium, most of it that is contained in a banana (radioactive or not) will be excreted after the usual transit of around 24 hours. During that time there will be some exposure but the dose will be orders of magnitude smaller than that given by the B.E.D idea.

isn't quite right. K equilibrates, but there's no guarantee -- in fact it's statistically very nearly the opposite -- that if you're full up on K you excrete the banana's potassium. Instead K atoms are exchanged throughout the body, and it's just chance whether a particular atom stays in the body or not.

This is also why the point about BAD not being realistic isn't quite right either -- the banana, once eaten, stays in the body and adds to K load until excreted by the kidneys, a period of several hours at least. This total dose does go up, by a quantity of dose-rate×that interval.

Charlie (Colorado) (talk) 06:17, 19 March 2011 (UTC)

BED assumes the K is assimilated by the body and remains there. This is grossly wrong and gives a dose several orders of magnitude greater than what you are suggesting, which seems close to the reality.

Even the original citation for BED gives NO explanation nor does it state the (false) assumptions on which it is based. —Preceding unsigned comment added by 95.176.126.166 (talk) 10:21, 19 March 2011 (UTC)

The Banana Equivalent is by definition the radiation absorbed by eating a banana, that would not have been absorbed if the banana were not eaten. Your objection seems to be one of how the actual dose is calculated - see the Clarifying Specifics of Calculation section above. 118.208.151.251 (talk) 11:53, 19 March 2011 (UTC)
 * Because the potassium in a banana does not emit all of its radiation the instant it is eaten, you have to measure the dose over the time period in which that extra potassium is in your body. You might note that radiation from Fukushima I has been measured in uSv/hour. There is no time period given in the University of Nevada Reno PDF, from which the 0.1 uSv value from the BED appears to come from. It seems that they mean that there is about 0.1uSv "in" the banana, but since that radiation doesn't come out all at once, we have to look at the period over which that radiation is emitted. In the case of potassium-40, its half-life is about 1.25 billion years, from which we can compute a mean lifetime of about 1.8 billion years. This value of 1.8 billion years is significantly longer than the value of 24 hours, suggested above, that the excess banana potassium remains in the body. - Afiler (talk) 23:29, 19 March 2011 (UTC)
 * See the Clarifying specifics of calculation section above. 0.1uSv would match up with about 1000 hours of all the K40 radiation from a banana being absorbed by 70kg of tissue. PeteSF (talk) 23:47, 19 March 2011 (UTC)
 * It may be that your calculations are correct, which would mean that there is an error in the University of Nevada Reno PDF, which is the only source for a value for a banana in Sieverts. If that PDF is wrong, then that means we have to rely on Wikipedia editors to do these fairly complex calculations accurately.
 * If we decide that we don't want to cite a particular value at all, then there is no "equivalence" in the "banana equivalent dose", then the statement of this article is basically "bananas have nonzero radiation, but we have nothing more specific to compare their radiation to". -- Afiler (talk) 00:30, 20 March 2011 (UTC)

Good grief, people. Grow up!
This was a concise and useful article a few days ago. Now it's been bastardized by a bunch of agenda-wielding wankers, and somebody got butthurt that they lost an edit war and made it a candidate for deletion. What good does that do for anybody???

This doesn't have to be a political struggle folks, it's juuuuust a little bit of pop science to help non-technical people get their heads wrapped around relative levels of danger and the wide ranging orders of magnitude involved in radiological measurements. There's nothing to argue about as long as the decimals are in about the right spot, because nobody EVER claimed it was some sort of precision measurement. It's juuuust like using a pea and a basketball three blocks apart to show the relative size of the earth and sun. That's allll it is. Calm down.


 * Indeed, this appears to be a much more useful version of the article. --Kvng (talk) 15:12, 20 March 2011 (UTC)


 * Yes, yes. It's absurd that the 'See also' section with links to different radiation units has been deleted. Davy p (talk) 18:28, 21 March 2011 (UTC)


 * I agree. Roll it back to the earlier version. The micromort being also the risk of driving 40km is the only useful addition since. — Preceding unsigned comment added by Innovan (talk • contribs) 03:58, 22 March 2011 (UTC)

Well trying to get any accurate information into WP is always a major political battle. Too many zealots with agendas who are not disturbed by a lack fact.

You say it was "concise and useful article a few days ago." Yes the misinformation was concise, the page layout may have been better. The big problem is this globalised urban myth is total crap.

" There's nothing to argue about as long as the decimals are in about the right spot " I totally agree. If they were I would not have been interested. The trouble is when you do calculate the BED it's about 350 times less than stated here. Since nowhere is there a link to how this is calculated or on what physics and biology it is based one can only guess at the source of the error. That in itself should negate all arguement. This is totally unsubstantiated.

I have added two refs that explain that the body chemistry of K is very important in looking at the dose but that does not seem to be enough for some. In fact there is repeated sabotage to remove and edit these sources.

But we all know that's how WP works and that's why it is of little use as a reference. — Preceding unsigned comment added by Climatedragon (talk • contribs) 08:55, 22 March 2011 (UTC)

Really disputed?
If I read the cite correctly, the dispute on whether Banana Equivalent Dose is a valid measure or not is based on a citation of an article on Boing Boing by an author of a book self-published by Lulu.com? 78.80.1.112 (talk) 03:44, 20 March 2011 (UTC) ClimateDragon's choice for a reference is to a blog article that references this very Wikipedia entry is ITS source and quotes text that no longer exists. Circular references are not acceptable and frankly sloppy. —Preceding unsigned comment added by 98.127.14.116 (talk) 22:29, 21 March 2011 (UTC)

I think there is room to point out that there is disagreement about the concept, but I think there should be a Criticism section written for that. Putting the Boing Boing link in after the opening paragraph wrecks the article, and thusly I have removed it. The link still exists in External Links, which is where it probably belongs, if it belongs at all, and if it's not being used as a citation.74.61.32.25 (talk) 07:20, 22 March 2011 (UTC)

Disputing the relevance of the concept itself in the opening is not Standard Format. Standard Format requires criticism to be at the end, much later in the article, in its own Criticism section. Having an entire quote in a break away standalone paragraph is overemphasis. And then having the entire sentence linked instead of footnoted, again, not only breaks Standard Format, but looks sad and desperate. "Radioactive iodine is exceptionally dangerous to children as it concentrates in the thyroid." is non sequitur and instead should be in a Criticism section as well. The Criticism section also has to be constructive to be useful for readers. If this model is so flawed, what are alternative, better models that are still easy to grasp for the public because it's related to something they see and do in their day-to-day lives? Most everyone has the personal experience of peeling and eating a banana. They're common, everyday objects. Peanut Butter is something more restricted to only US households, and eating "40 teaspoons" is not as easy to grasp (particularly for metric countries) as "one banana". Brazil Nuts and mushrooms are even less common to the average household. I like the cross-comparisons, but just saying "the 40 teaspoons of Peanut Butter Equivalent Dose" already shows how awkward it is. We should also somewhere be specific that the banana variety is the http://en.wikipedia.org/wiki/Grand_Nain cultivator of http://en.wikipedia.org/wiki/Cavendish_banana. The Grand Nain is the fourth most cultivated crop in the world, so much more likely to be something the average public has handled and seen in their lives. And in a later section we should probably be specific as to the weight of "one banana" and how much K and K40 are in "one banana" since people are now coming here for the math.

It's interesting in critisising the boingboing ref that you omit the fact the person quoted is former UK Atomic Energy Authority. The part of the citation got removed by an earlier editor. Maybe he felt it was not appropriate.

As such she is the ONLY competent source for this article, and neither is she some eco-loon with an agenda. Some people with agendas seem to want to propagate this urban myth at all costs and don't give a damn that it is not factual. — Preceding unsigned comment added by Climatedragon (talk • contribs) 08:44, 22 March 2011 (UTC)

Maggie Koerth-Baker is a blogger/editor who did some research in contacting Geoff Meggitt, who she quoted indirectly in the cited BoingBoing article. Geoff Meggitt (http://tamingtherays.com/) is a retired health physicist that worked with the UK Atomic Energy Authority and its commercial spin-offs. His book on the subject, Taming the Rays, is published on lulu.com, which seems to carry a stigma of vanity publishing (merited or not). Regardless, his research has been published in 2006 in the Journal of Radiological Protection. I would have loved to have corrected this, but the Wikipedia instructions on how to cite correctly made me cry. Tinfoiled (talk) 13:29, 22 March 2011 (UTC)

Who is Maggie Koerth Baker? ... and Geoff Meggitt
According to her own website http://maggiekb.com/ she is a " writer, editor and all-around idea maven based in Minneapolis, Minn. Always a sucker for random, cool facts and great stories, she now makes her living spreading interesting information far and wide. This is every bit as awesome as it sounds. She's also a contributing editor to the award-winning blog, BoingBoing.net."

Accrediting her as "former UK Atomic Energy Authority" appears to be a serious error. — Preceding unsigned comment added by Innovan (talk • contribs) 12:41, 22 March 2011 (UTC)

The original attib explaining why potassium cannot be treated like this was incorrectly attributed to Maggie, who is in fact an author and journalist (printed and web).

The UK Atomic Energy Authority source is Geoff Meggitt. 95.176.126.166 (talk) 16:23, 22 March 2011 (UTC)

More detail on his background. Sounds like a credible source on the subject

Except no one can provide the source where he says the quote attributed to him. The quoted wording never appears in the boingboing article that is cited as the source as a quote from him, it only appears as the author's opinion of what he said. And searching the text from his book "Taming the Rays" for the word "banana" shows 0 hits. As such, it should be removed as falsely attributing a quote to a living person. Innovan (talk) 18:17, 22 March 2011 (UTC)

http://tamingtherays.com/

Geoff worked as a health physicist for the United Kingdom Atomic Energy Authority and its later commercial offshoots for 25 years with particular interests in risk assessment, internal dosimetry, waste management, nuclear criticality and accident response. For five years in the 1990s he was Honorary Editor of the Journal of Radiological Protection.

Since retiring in 2002 he has spent some of his time researching the history of nuclear technology and radiation protection. The results so far are a short history of nuclear criticality safety (Fission, critical mass and safety - a historical review, J Radiol Prot 26 (2006) 141-159) and this book.

Tidying Up Criticism Section
OK, so obviously we needed a Criticism Section, both to present an opposing point of view, and also to give anti-nuke zealots a place to have their say without ruining the article's purpose of explaining the idea of BED. Fair enough. But let's keep it factual, shall we?

First thing we see today: "The radioactive risk from accumulation of potassium in the thyroid gland also has to take in account how full of potassium the individual's gland already is."

Um, right. Potassium doesn't accumulate in the thyroid. That's Iodine. AFAIK, bananas are not even a source of Iodine. Thus... I'm changing references to "thyroid" to "the body".

The next sentence is also clearly related to an editor's confusion of Potassium and Iodine: "Children whose bodies are still developing have a greater risk from exposure to radiation, both because of their higher consumption of potassium while their body size increases, and from having more ongoing cell division during their growth cycle than an adult past developmental growth."

I'm removing that altogether, as this statement is unsupported by reference.

Next: "The BED can be misconstrued as implying bananas are dangerous to eat because it contrasts the commonly understood risk of eating a banana with many events considered much more risky by the uneducated public."

Huh? The whole purpose of BED is to convey the idea that very low doses of radiation are NOT dangerous. Removing this sentence because it is the editor's opinion, not supported by reference, and silly.

And finally: "So important that the thyroid gland stores potassium for later use."

There's that pesky thyroid again. Doesn't belong in this article, at least not until someone brings forward a source stating that Potassium accumulates in the thyroid. (Good luck with that).

I'm the one who suggested a Criticism Section in the first place, so obviously I should support its continued existence. But let's not make stuff up, eh?Belchfire (talk) —Preceding undated comment added 14:08, 22 March 2011 (UTC).

Thank you for the edits. :-) Don't like "whose body is already full" --it's sounds like someone is full from eating bananas, not a gland has reached max storage capacity.

The confusion on my part is I really should have written Potassium-Iodine, which I familiar with being used to saturate the thyroid during nuclear medicine. Sources: http://www.health.state.ny.us/environmental/radiological/potassium_iodide/information_for_physicians.htm http://www.anbex.com/nrc_profile_doc.php http://ki4u.com/

Eating elemental iodine by itself is poisonous. Orally, you only should take potassium-iodine. In a pinch you can use skin absorption of a painted strip of Povidone-Iodine (10%) http://www.ki4u.com/plan_b.htm but never take iodine orally by itself.

Iodine is what's stored in the thyroid, including radioactive iodine. Potassium 40 is what's radioactive in bananas. The storage of Potassium by itself, unlinked to iodine, by the thyroid is beyond my personal knowledge. Innovan (talk) 14:53, 22 March 2011 (UTC)


 * I guess it's not so much making stuff up but someone's failure to notice when they don't understand something. I think there is a technical point to be made and a psychological one.
 * The technical point is that even the equivalent dose is not a good measure for radioactive food because it doesn't tell us anything about what happens when we eat it. While the BED has probably been coined as a particularly harmless example for external exposure, the fact that a banana is food automatically makes people think of the BED as a measure for effects from radioactive food. But when seen in that context it is not appropriate.
 * The psychological point is that the general public has no sense of dimensions. E.g. 1,400 microsievert per day sounds a lot more dangerous than 0.7 sievert per second. Most people either fall into inappropriate panic or become inappropriately careless. The BED concept is probably quite effective at moving the public towards carelessness. Hans Adler 15:08, 22 March 2011 (UTC)


 * It seems that most of the pedantic nitpicking here is based on disagreement about the precision and accuracy of BED, while managing to completely ignore that BED was never intended to be a precise thing. As I stated in another section, and as the article itself states, BED is only an illustration meant to put risks in context.  Obviously there are numerous factors that will sway the exact dose one way or the other, but that is entirely irrelevant to the concept as a whole.  Again, as long as the decimal is in the right place, the values expressed will be sufficiently accurate to convey the idea.  Arguing about how much is consumed vs how much is absorbed may or may not yield a scientifically accurate article, but it is superfluous and overly wonkish to apply those standards here.  Belchfire (talk) 15:21, 22 March 2011 (UTC)


 * According to this source, estimates for the ratios between effective dose and committed effective dose equivalent can vary significantly for some substances: up to five orders of magnitude! Unfortunately the only concrete numbers that I found are in this paper. If these numbers are correct, then it does in fact look as if bananas are representative even for ingestion. A priori I would have expected the values for potassium to be low to medium, so that some substances may well be several orders of magnitude more dangerous. This is all not excessive pedantry but very relevant: When people think of a banana, they think of eating it, not of sitting next to it.
 * I am not proposing to put my "original research" into the article. I am just explaining why the critical source cannot be dismissed so easily and should be taken seriously. Hans Adler 16:06, 22 March 2011 (UTC)
 * If the difference is indeed five orders of magnitude, that is very significant and worthy of mention. I see nothing wrong with including such information, so long as it is not done in a way that destroys the basic idea that BED attempts to convey.  Perhaps a new section explaining the various dose modes is needed? Belchfire (talk) 16:15, 22 March 2011 (UTC)


 * The problem is we are getting rather far from what is published about the original topic. Wikipedia can be quite good for such "original research", but not when a topic is even slightly contentious.
 * I just realised that I apparently misunderstood the concept of committed effective dose: It is only about the fraction that is actually ingested, and says nothing about how much is ingested. This explains why most factors in the table I found are close to 1. Maybe the source that mentions extreme variation included sources that account for typical accumulation rates, but that's just speculation. Hans Adler 16:36, 22 March 2011 (UTC)

Thank you for work on some of that totally spurious and incorrect content. There is enough of that in this whole BED-wetting article.

"OK, so obviously we needed a Criticism Section, both to present an opposing point of view, and also to give anti-nuke zealots a place to have their say without ruining the article's purpose of explaining the idea of BED. Fair enough."

This is not a case of points of view so no-one needs a special section tucked away down the page to "have their say.

"But let's keep it factual, shall we?" That what I've been trying to do for the last four days but it's an uphill battle. It seems that someone who worked for the UK nuclear industry and actually knows how the body works, and why this whole idea is wrong is not good enough for you. I guess he must be one of those anti-nuke zealots you refer to.

Look up the source linked here for the Geoff Meggitt quote. The supposed quote does not appear in the actual article. Download a copy of "Taming the Rays" from amazon, which is a "a history of the use of X-rays and nuclear radiation". The word banana appears zero times, hardly surprising since it is doubtful that the early Geiger counters he writes about could even detect 0.1 μSv. Geoff Meggit appears to have worked for the UK Atomic Energy Authority in the 1970s, moved over to a private consulting agency, retired in 2002, is a historian, and has occupied his time since with history of nuclear technology, with a particular emphasis on Geiger counters and other detection methods, and improvements in their sensitivity. He is not a licensed physician, but instead worked as as "health physicist". It appears, just as Maggie Koerth-Baker turns out not to be a UK Atomic Energy Authority who said this supposed quote, Geoff Meggitt never said this quote either. It should be removed. 63.204.130.177 (talk) 17:21, 22 March 2011 (UTC)

Now take a deep breath READ what he explains and stop sabotaging factual content because it does not fit your ideology or that ever else you have going on.

"let's keep it factual, shall we?" 95.176.126.166 (talk) 16:32, 22 March 2011 (UTC)
 * All well and good. There is room in the article for your contribution, but I don't feel it should go at the top of the page.  I started the Criticism Section for that purpose, and there seems to be agreement among other editors that this was appropriate.  Placing the Meggitt link in the opening section, where the basic concept is being explained, appears to be sabotage to this editor.  See WP:DE. It seems strange that you remove the Criticism section because it is redundant, after you have inserted critical information into the article.  Why not just place your criticism in the Criticism Section, instead?  Belchfire (talk) 16:48, 22 March 2011 (UTC)
 * Criticism sections are only used by Wikipedia as a last resort. We normally prefer to fold any criticism into the rest of the article. I not that the "flawed concept" language seems inappropriate to me. I think the first thing we should do now is to clarify whether the BED is intended for comparing external exposure to radioactivity or for ingested radioactivity. If the former, then it was misleading to use food of everything, but is otherwise valid. If the latter, then I would agree it's flawed, but would still not be sure that we can say so explicitly in the article. Maybe it's not clear in the real world which it is supposed to be. In that case we will need to find some compromise language that is open in all directions. Hans Adler 16:55, 22 March 2011 (UTC)


 * I don't feel BED is intended to compare one kind of dose to another, i.e. external, internal, absorbed, etc. Rather, it is intended to put everyday sources of radiation in scale with otherwise unintelligible raw numbers, like what we have seen in the media as of late.  This is why the precise dosage figures are less important than just putting the concept of a banana at approximately the correct place along a continuum.  Clearly, the idea is both flawed and disputed.  No argument there.


 * My issue at the moment is with the flow of the article. I think it should first explain what BED is, then how it is calculated, then how it compares to other radiation sources, THEN why it may or may not be a precisely accurate in the real world.  After all, the purpose of the article is to explain BED to those who are curious about it... not so much to debunk it.  Putting information such as the Meggitt article at the top of the article is obviously intended to defeat that aim.  Belchfire (talk) 17:06, 22 March 2011 (UTC)


 * May I ask everybody who needs it to calm down now. An escalation helps nobody. To make an article really good we often need opposing viewpoints. The latest instance of unhelpful language, by the way, was "vandalising", which has a precise technical definition that does not apply to anything that has happened at this article so far. Using the word loosely is very strongly discouraged. Hans Adler 16:44, 22 March 2011 (UTC)


 * Agreed that escalation is unhelpful. I think we should discuss how to incorporate the unsigned user's contribution in a way that doesn't defeat the purpose of the article.  Belchfire (talk) 17:15, 22 March 2011 (UTC)

Tidying Up Article
Agreed, agreed. So what do you think is the purpose of the article. Maybe that is the point of confusion. I thought it was to explain what BED is in a factual scientific way. That it is based on a total ignorance of biology of potassium and states a dose several orders of magnitude larger than reality would seem to be absolutely the most important fact for the article to contain. Once that is realised the rest of the content becomes pretty irrelevant anyway, so once there is more solid referencing of the facts the rest of the article can probably go. Climatedragon (talk) 09:13, 23 March 2011 (UTC)

XKCD article is relevant as an External link. Please stop deleting.
The Radiation Dose chart on xkcd.com is relevant. It compares the 0.1 μSv of eating a banana to the 1μS of x-raying one arm, the 1 μSv from using a CRT for 1 year, the 5 μSv of a dental x-ray, the 40 μSv of flying from New York to LA (one-way), the 70 μSv of living in a stone, brick or concrete building for one year, the 390 μSv yearly dose from natural potassium in the body, the 1000 μSv EPA limit on yearly exposure to 1 member of the public, the 3,000 μSv of a Mammogram, the 3,650 μSv that the average person is exposed to annually (mostly through background radiation), the 5,800 μSv of a chest X-ray, the 50,000 μSv limit from the EPA for yearly exposure for any radiation worker, the 100,000 μSv amount that is the lowest amount of exposure linked to cancer, and other data NOT included in this article. And it does it in a graphical form. People who are trying to understand radiation levels through the BED are also going to appreciate the XKCD chart. 63.204.130.177 (talk) 16:45, 22 March 2011 (UTC)
 * To quote xkcd: "I’m not an expert in radiation and I’m sure I’ve got a lot of mistakes in here".
 * That’s a legal disclaimer for sue-happy America despite his best efforts at information gathering. He continues “it’s for general education only. If you’re basing radiation safety procedures on an internet PNG image and things go wrong, you have no one to blame but yourself”. It's reasonable to not want to be held in court for damages from people following your advice on radiation exposure levels on the internet. Innovan (talk) 23:55, 22 March 2011 (UTC)
 * It doesn't matter what it is so long as he isn't an expert on the topic, and I think nobody would claim that he is one. I am not taking the "lot of mistakes" seriously. That's not the point. See WP:SPS for the high standards that we expect for self-published sources. For external links we have similarly high standards that mostly rest on these. Hans Adler 01:06, 23 March 2011 (UTC)


 * You're talking about http://blog.xkcd.com/2011/03/19/radiation-chart/, I'm talking about http://xkcd.com/radiation/. And while on his blog he states that he is not an expert, he also states the chart was written with the help from students at Reed studying nuclear science and with the help of the Senior Reactor Operator at the Reed Research Reactor. Innovan (talk) 18:11, 22 March 2011 (UTC)
 * The graphic or the blog post where he presents it, that's basically the same thing. It's self-published, and he admits that he is not an expert. Even the students themselves would not count as experts, although their professors might, but not when filtered through xkcd. Therefore it's not usable as a source, and for external links we have rather strict rules because of all the link spam that people are pushing here. Hans Adler 18:18, 22 March 2011 (UTC)
 * So how about http://people.reed.edu/~emcmanis/radiation.html, which was the inspiration for the xkcd chart? Innovan (talk) 18:51, 22 March 2011 (UTC)
 * Ah, so that's where the banana number comes from! I think it's a borderline case. I still doubt the number for eating a banana, but now we have it from a borderline reliable source. (Self-published source from someone who is a borderline expert.) I would not object to inclusion, but I don't know about others. However, if and when the article matures it will have to go at some point because of WP:ELNO #1: In a featured article we would have our own graphic. But in the meantime it makes sense to tolerate such a link. Hans Adler 19:21, 22 March 2011 (UTC)
 * The BEQ number quoted on that chart, unfortunately, is a circular reference back to this BED article, although the rest is references to sources outside wikipedia. The BED was cited in this 2004 article as roughly 0.01 mrem. Radiation Safety Using 1 μSv = 0.1 mrem from http://en.wikipedia.org/wiki/Sievert converts it to the current 0.1 μSv. Physical Insights did its own math in 2007 and came up with a CEDE of 0.005 mrem, which is half the 2004 number. However, PhyIn doesn't cite the weight of his original banana, where as the 2004 source cites a "medium" size banana. From the USDA for "SR 21 09040" (ie raw bananas) we have that 150g of raw banana is 1 cup by volume and contains 537 mG of Potassium, so Rad Safety appears to be using a 125g banana as "medium size". Innovan (talk) 20:46, 22 March 2011 (UTC)
 * Thanks. I still don't trust that number, but that's without doubt a sufficiently reliable source for the purpose, at least until conflicting information comes in from elsewhere that doesn't require as much computation as I did. (Has this been in the article all the time? Oops.) Hans Adler 20:21, 22 March 2011 (UTC)


 * OK, a banana contains 0.1μSv because of the potassium-40 it contains. Potassium-40 has a half-life of 1.3 billion years. So in order to get half of that radiation from a single banana you must (1) put the banana in a body cavity, making sure it stays there for the full period of time, and (2) wait for 1.3 billion years. Of course you can use several bananas to get things done faster, but I challenge you to get more than a thousand bananas close enough to your body so that they make any difference.
 * The numbers seem to be better than I thought, though not correct. I could not find any definitive information on the effective dose from eating a banana (our article only gives Becquerels, by the way, which is something totally different), but here is the calculation: An average human body (70 kg) contains about 300 times as much potassium as a banana. The potassium-40 in the body contributes about 200 μSv per year to our internal effective dose. It follows that over a full year a banana would contribute about 0.5 μSv. To contribute 0.1 μSv it would have to stay in the body for 2 1/2 months, which seems extremely long. I think 1 or 2 days is more realistic, resulting in 0.001-0.003 μSv. So it looks as if xkcd's effective dose for a banana is 100 times too big. Hans Adler 18:13, 22 March 2011 (UTC)
 * On the other hand, the 1μSv of an x-ray is what actually goes through your body at once. Or maybe it is what is absorbed -- I don't know, and one should really know before comparing, which is why we need sources from experts. In any case we can be pretty sure that a considerable fraction of it (> 1%, I guess) will stay in your body. All things considered, I am pretty sure that the total number of bananas that you will see over your lifetime will be less than the number of bananas that you would have to be exposed to continuously throughout your life in order to get the dose of a single x-ray. Hans Adler 17:21, 22 March 2011 (UTC)
 * Or to put it formally: The link is inappropriate because of WP:ELNO, items 2 and 11.


 * Item 2 is not applicable. The chart is well sourced. The sources are even printed on the chart itself. The chart itself is clearly intending to be rigorous and factual. Unlike, say, boingboing articles.
 * Item 11. is not applicable. The site isn't a blog or personal journal, and in fact is a commercial and well recognized site that has already cited many times in wikipedia. Enough so that there is a special wikipedia policy on citations to XKCD. http://en.wikipedia.org/wiki/Wikipedia:Xkcd_in_popular_culture
 * Xkcd gives sources for the chart, but I cannot find the information on the effective dose from a banana anywhere. That's not what you would expect, so at least in that respect it's misleading. In any case it's unreliable because he is not an expert. And the graphic is self-published, which is what item 11 is about. If you don't believe me, you can always ask at WP:External links/Noticeboard for a few more opinions. Hans Adler 18:26, 22 March 2011 (UTC)
 * Update: The source for the BED has been provided elsewhere on this discussion page, and has been present since 2010 if you're willing to go back 500 or so edits in the edit war. It is the 2004 University of Nevada presentation on Radiation Safety. Innovan (talk) 23:45, 22 March 2011 (UTC)


 * Based on this XKCD specific wikipedia policy, the link should be included. It is not merely a "This article in wikipedia was mentioned in this XKCD comic" link, but an interesting chart that graphically displays information beyond the original wikipedia article, helping users to visualize radiation levels in a way similar to the mental model of the BED itself. Innovan (talk) 18:11, 22 March 2011 (UTC)
 * Please make sure to use indentation correctly, ideally don't put your comments inside other people's, and don't simply delete other people's comments when there is an edit conflict. Thank you. Hans Adler 18:15, 22 March 2011 (UTC)


 * By the way, I love xkcd, but here he simply got the details wrong. Which is a pity, because how gives an idea of the scales involved is of course is of course very good. Hans Adler 17:27, 22 March 2011 (UTC)

Innovan, thanks for your research, especially for finding this link. I think this computation is flawed, and essentially for the reason explained in the Boingboing article. The published CEDE values tell us the additional equivalent dose that accumulates over the next 50 years per amount of radioactive substance that is integrated into the body. You may ask why I know it's not per amount of radioactive substance ingested. Well, I haven't seen this made explicit, and so here is why only the former makes sense:

The additional equivalent dose as a function of ingested potassium-40 depends on concentration as well as amount, and in a non-linear way. If you ingest potassium, then your body is likely to use some of it (more or less) permanently, but, having been already saturated with potassium, will release the same amount of potassium previously present there. This is already mentioned in our article (the reference to homeostasis). So we see that the actual equivalent dose that results from ingesting potassium depends on the concentration as much as on the amount, and it also depends on accidents of digestion and metabolism. Since the CEDE exists for applications in radiology, and because the literature on CEDE says explicitly that the number of years over which one integrates matters (and is taken as 50 years for adults, more for children), the normal published CEDE factors must be for the third case. Since the relation depends on concentration as much as amount, and the concentration is never mentioned in the literature, the determining number must be the net value of additional radioactive substance integrated in the body.
 * First let's suppose the concentration of potassium-40 relative to all potassium in your body is the same as the concentration in the ingested potassium. Since your body doesn't distinguish between stable and radioactive potassium, the concentration will remain the same, and so the total amount of potassium-40 that is part of your body will remain the same. Therefore the additional dose has just a day or two to accumulate before you go to the loo. After that, everything is as before. The resulting effect is what I tried to compute above. (My result seem too big compared with the numbers in the article.)
 * Second, if you ingest potassium that has a lower concentration of potassium-40 than your body does, then again there may be an exchange to some extent. If so, then the concentration of radioactive potassium in your body will decrease. (However, after eating a few bananas it will probably be back to normal.) So you have a tiny additional equivalent dose while the stuff is in your body, and then a tiny negative dose (compared to your normal internal radioactivity) over a potentially longer period: until everything is back to normal.
 * Third, if you ingest potassium with a higher concentration of potassium-40 than that in your body, then if there is time for an exchange (which presumably depends on details of your digestion), you will end up with a higher concentration of potassium-40 than before. Again, after eating a number of bananas you will be back to normal. (If your potassium-40 concentration has been very significantly increased, then it would be conceivable to me that you will need years to get back to normal.)

This is also confirmed by the fact that most CEDE factors for conversion from equivalent dose to CEDE are very close to 1. (I am contradicting myself further up now. I found a source that says that even for the same substance, literature values vary by up to 5 magnitudes. But that's not what I have seen.) If they were in relation to radioactive substance ingested, they would have to be orders of magnitude higher for iodine than for potassium.

So it turns out that the correct value should be five orders of magnitude lower than what is computed in the blog. The blog computation assumes that all the potassium-40 from the banana remains in the body as additional radioactive substance, for the next 50 years. But actually it only stays in the body for, say, two days: 50×360/2 = 18,000/2 ≈ 10,000. Hans Adler 22:05, 22 March 2011 (UTC)

PS: I now see that comment #29 for the Boingboing post says the additional potassium actually stays in the body for about 20 days. This results in a factor of 1,000, so that instead of the 0.1 μSv in our article the correct value should be 0.1 nSv. However, the same person who posted this also said that on this basis they make the value 0.1 μSv. Odd. Let's hope that this article inspires an expert or two to discuss the topic properly in a textbook that we can then cite. Hans Adler 22:48, 22 March 2011 (UTC)

Dose from eating one banana: http://en.wikipedia.org/wiki/Banana_equivalent_dose
 * Earlier comments that xkcd used a nuclear student as source, he links to her simpler graphic that inspired the xkcd version. http://people.reed.edu/~emcmanis/radiation.html
 * checking the sources at the bottom of that page we find the source of the banana irradiation figures used by this rigorous, knowelesgeable science student so keen to educate the masses:


 * So the circle of disinformation is complete. The bullshit now circling the world in graphic form originated here. Go wikipedia!

xkcd is a great comic. That does not qualify it here. —Preceding unsigned comment added by 95.176.126.166 (talk) 08:18, 23 March 2011 (UTC)


 * I was going to contradict you about "student", but it appears that Reed Research Reactor has an awful lot of "Senior Reactor Operators", and I did in fact not find any evidence that Ellen McManis is a researcher with any standing. So anything self-published by her is probably not usable as a source. Hans Adler 10:08, 23 March 2011 (UTC)


 * Good point, I had taken at first value xkcd's claim she was a student. If she is it is very sloppy of her to use such a notorious unreliable source as WP as a ref. In the UK even school children are told not use it for their homework!
 * The number of "Senior Reactor Operators" also struck me as a bit odd. I made me think of all the "managers" that fill supermarket shelves. Climatedragon (talk) 11:35, 23 March 2011 (UTC)

POV/NPOV flag
Some one had put an NPOV flag on this article that says refer to discussion but they have put nothing here to discuss.

This whole discussion has been been about factual accuracy and sourcing of information. It is a scientific article that has no place for POV from any angle. The fact the person who added the flag sees it as POV probably reflects more on their efforts than those of others here trying to find the facts behind the dose of a banana.

Since I see no POV arguements or content here I'll remove the NPOV flag. There is already a flag to indicate the problems with sourcing. That is the real issue.

If anyone thinks there is POV content here. Please state clearly what it is here and discuss before starting another wikiwar. —Preceding unsigned comment added by 95.176.126.166 (talk) 08:34, 23 March 2011 (UTC) Climatedragon (talk) 08:45, 23 March 2011 (UTC)

The quality of this article
Huge shitstorm incoming. What the fuck is wrong with you? This article was in a pretty good shape a few days ago and now it is best described by these words: Complete Bullcrap. The retard above me sees no POV in this abomination of an article beginning with "XYZ is a *flawed concept*". Okay. WHAT THE FUCK? Any lobotomized flatworm should be able to tell you, that the term "flawed concept" is a highly subjective and opinionated term. It certainly is not appropriate for a fucking encyclopedia (which Wikipedia wants to be, I think). The information content is virtually zero, the page basically says "Yo motherfuckers, your BED concept sucks", instead of exposing the concept and presenting the opposing view of homeostasis and all that shit. Now it has weird childish opinionated and suggestive phrases sprinkled all over it ("The human body does a pretty good job of regulating potassium"). I'd really like to change it, but as I know you, some of you retards are going to change it back; a tendency visible all over the encyclopedia that any hobo can edit.

FUCK

THIS

SHIT

--79.240.222.48 (talk) 13:26, 23 March 2011 (UTC)


 * Please watch your language. Also, this kind of language makes you look a bit silly if it turns out that you didn't make your homework before commenting. You seem to be commenting on Climatedragon's 8:34 comment. At the time the article looked like this.
 * There is a lot of back and forth on this article due to people having different viewpoints on various things. For me the main thing is whether the dose equivalent given is correct within one or two orders of magnitude, or not. Initially I found the argument in the Boingboing source that it is not very convincing. Now I am slowly coming around to the view that the argument given by the source was probably taken into account. But it's very hard to say with so few sources and most of them of extremely poor quality or with very few details. You basically have to guess all the time. Not even the papers computing CEDE factors say clearly enough what it is they are computing. Presumably it's defined in ICRP 53, but that's not freely available.
 * Shouting and swearing doesn't help in this situation. Pointing out good reliable sources (online or offline, in the latter case preferably with quotation of pertinent passages) does. Hans Adler 15:12, 23 March 2011 (UTC)

Hi there Mr. Anon WTF, thanks for your contribution. Speaking as a lobotomized flatworm / retard, I would just like to point out that if something that is supposed to be a scientific fact, a dose to which we can compare others, is out by a couple of orders of magnitude this may reasonably regarded as a flaw. The proposition then becomes flawed. That is not "highly subjective and opinionated". Nor is it POV. It is a simple statement of fact. In view of this huge error all the rest becomes rather irrelevant. IMHO this article should stop there, but I'm holding out for some solid refs since no-one who is propagating this notion (on web, in press or here) is able to provide a credible ref nor an explanation of the basis of the calculation.

I agree with your comment about that phrase but in the absence of fact I regard literary style as fairly secondary. (like a couple of orders of magnitude secondary). I have also refrained from editing it because someone would likely object and it's pointless at this stage.

The quality of this article would be improved by some solid refs to someone who says how this is calculated.

BTW Don't worry about apologising, that comment was a blast. ;) —Preceding unsigned comment added by 95.176.126.166 (talk) 16:10, 23 March 2011 (UTC)

adhoc calcs
Maybe we could resume any rough calculations here.

Hans: "(If your potassium-40 concentration has been very significantly increased, then it would be conceivable to me that you will need years to get back to normal.)"

The biological half-life of K is about 30 days but that deals with the change-over of the actual K stock in the body (muscle tissue etc), not the elimination of any excess in the blood. The proportion of K40/Ktotal in the body is not affected by all this. The main factor needed to calculate a dose is to know how long healthy functioning kidneys will take to eliminate any excess.

I believe this to be pretty short since hyperkalemia has fairly severe consequences and we don't see reports of people being rushed to A&E after eating too many bananas, nor for this to be a problem in cultures where banana is a staple. Climatedragon (talk) 16:40, 23 March 2011 (UTC)

First let's calcuate the dose due to it's K stock.

http://ajpendo.physiology.org/content/284/2/E416.full Potassium in the (fat-free) body : TBK/FFM =68mmol K /kg = 2.65 g K/kg (0.068 x 39)

total K in body per kg body weight = 2.65g ratio of K-40 in nature 0.012% of total K. radioactivity of K-40 = 264 Bq /mg

http://www.sialme.com/getattachment/Conference—Workshops/Conference/Mabrouk-Allagi_K-40-in-dates-and-honey.pdf.aspx http://www.sialme.com/getattachment/Conference---Workshops/Conference/Mabrouk-Allagi_K-40-in-dates-and-honey.pdf.aspx — Preceding unsigned comment added by Climatedragon (talk • contribs) 01:28, 26 March 2011 (UTC)

max beta energy of K-40 decay = 1.3 MeV. (Typical decay is less, this is max) [I've simplified a bit, there's some (11% ) 1.5Mev gamma and not all the betas will have the max energy, so I'm counting on the large side.]

1 Mev = 1.6 e-13 J seconds in one year 31.56e6

Rad = J/kg for beta and gamma exposure Rad = rem

energy/s of radiation from potassium in the body, per kg TBW: 2.65 x 0.012% x 264e3 x 1.3e6 x 1.6e-19 = 17.5e-12 J/kg/s

dose per kg body mass in one year: 17.5e-12 x 31.56e6 = 5.511 mJ/kg/year (=mrem/yr) =5.5 mrem/yr =55 uSv/yr

Don't start publishing that as a result either. Since most of this is in muscle tissue mostly superficial and in the main members most of this will only hit that same tissue or escape. You then need to look into the varying sensitivity of various tissue types to this radiation. A darwinian guess would say tissues high in K will be less sensitive, but I'm guessing. — Preceding unsigned comment added by Climatedragon (talk • contribs) 17:21, 23 March 2011 (UTC)

55uSv/yr from my personal K stock of 2.65g/kg x 80kg = 212 g means a nominal 450mg in a banana will radiate about 1/500th of that amount, 0.11 uSv/yr = 0.011 mrem/yr . Note, per YEAR.

So now we need some handle (ref) on how long the K excess from eating (swallowing) a banana will remain inside the body.

My gut feeling at this stage is that the original source did not intend to give a total dose but a dose per year (mrem/yr) and like so many people either confused the units, the context or a typo crept in. They also, having no knowlege of the biology of homeostasis, assumed once in the body it would all be assimilated and stay there indefinitely. This then was the dose per year that you would get. The rest is a sociological study on the creation and propagation of urban myths in a global village.

Or was it supposed to be a banana a day for a year ?? In any case misquoted or completely wrong.

Climatedragon (talk) 17:03, 23 March 2011 (UTC)


 * I've made a couple of minor clarifications to the section. It has been a useful excercise but is clearly original research and I've marked it as such. --Kvng (talk) 20:13, 25 March 2011 (UTC)

Yes, that section is a bit messy and clearly WP:OR. I am against any values being included for BED until something accurate can be found. That's why I put my calcs here to help understand where it comes from and not in the article.

I'm holding off on major editing until some FACTS can be found. At which point I think there should be a major overhaul.

This may be worth keeping an eye on: http://health.phys.iit.edu/archives/2011-March/031395.html

Seems like a clear expert confimation that origin BED claims are erroneous, though I don't know if that ML is WP quotable.Climatedragon (talk) 03:06, 26 March 2011 (UTC)

Discussion: EP:EL, WP:EL, boingboing, lulu, Meggitt, etc.
Here, User:Climatedragon asked me to discuss some of the above in re my three edits which immediately preceded that edit, saying "what's EP=EL? what exactly is banned. Discuss." I thought I had done that last night, but I apparently left that talk page edit unsaved. This is another try.


 * 1) The EP:EL redlink in the tanglefingered edit summary of this edit was meant to have been to WP:EL. I apparently saved that edit without proofreading the edit summary. WP:EL is a shortcut to External links, WP's content guideline for external links. It says therein, in part, "Wikipedia articles may include links to web pages outside Wikipedia (external links), but they should not normally be used in the body of an article." I note that an inline external link (EL) which I had removed in this edit has been placed back into the lead section of the article. I'll redo my removal of that inline EL after saving this comment. Also, please see Manual of Style (lead section).
 * 2) My next edit, here removed the pejorative "flawed" from the lead sentence of the article in re BED as a concept, and removed a Ref'd cite of . I mischaracterized boingboing in my edit summary there (my error), but boingboing still doesn't strike me as the gold standard of reliable sources.
 * 3) The boingboing article cited talks up the same source as the removed EL, the book: . That book is hyped on the web at tamingtherays.com/, and looks like interesting reading. I haven't read it. I wonder if anyone else here might have.
 * 4) The book is published by lulu.com. Lulu.com apparently offers editing, cover design, formatting, publishing and/or marketing services to authors wishing to self-publish books. I am unable to provide a conveninence link to their website here because they are on the Spam blacklist, and their being listed at the MediaWiki:Spam-blacklist prevents a link to anything on their website being placed in wikipedia articles or talk pages. One wonders how much of the talking up of the Meggitt book in this article and talk page stems from wikispam as a marketing tactic for self-published books.
 * 5) The Megitt book, anyhow, is apparently a self-published source, about which see Verifiability &mdash; I won't requote that here, but please do read it.

Following on the above, I will again remove the link to the boingboing article trumpeting the Meggitt book. Perhaps Meggitt is an expert (WP:SPS has some guidance about that: "... an established expert on the topic of the article whose work in the relevant field has previously been published by reliable third-party publications.) The tamingtherays.com/ website says that he worked as a health physicist for the United Kingdom Atomic Energy Authority and its later commercial offshoots for 25 years, and for five years in the 1990s he was Honorary Editor of the Journal of Radiological Protection. I wonder what his book has to say about the topic of this article. I'm traveling to the U.S. in a few days -- perhaps I'll check to see if it is findable in libraries there and try to take a look at it. Wtmitchell (talk) (earlier Boracay Bill) 21:36, 23 March 2011 (UTC)


 * First point WP:EL says it does not apply to inline citations and refers you to WP:IC which shows that the way that was linked was correctly formatted.


 * the rest of your comments are of the vein "hyped up" "talked up" irrelevant talk about lulu. So note, the text was not a citation from his book, no one gives a damn about hyping the book and the fact it was published on lulu is irrel. His book does look very interesting and knowledgeable but is about the 'history' of radiation and radiation safety , not bananas.


 * So it seems clear this guy is the nearest thing the whole damn subject has to expert comment. He explains why the biology of potassium is important. I agree the refs are not best but it does deal directly with the issue in hand and comments on BED and why it is wrong.


 * Now I don't see why you want to make a court hearing out of this and try to get this quote thrown out on some formatting or other technicality. This is not some kind of game of who knows the rule book best. You admitted in my talk page that the way you reverted some of my edits required explanation but then failed to provide one! It seems obvious from the beginning that your aim is to push your agenda irrespective of the facts and you are now playing around with edit rules in order to exclude a comment that displeases you.

The aim is to get accurate information with the best refs available. I'm still open to your coming up with better refs but so far you don't. That does not mean delete everything which is not perfect so stop deleting until you can do better.

Geoff Meggitt is clearly competent and his background suggests he is not some nutty eco-zealot, having spend his working life in the nuclear industry. Seriously, what more do you want? Stop playing games and come up with some better refs if you http://en.wikipedia.org/w/index.php?title=Talk:Banana_equivalent_dose&action=edit&section=20can be bothered.Climatedragon (talk) 23:56, 23 March 2011 (UTC)


 * Re your assertion, "First point WP:EL says it does not apply to inline citations and refers you to WP:IC which shows that the way that was linked was correctly formatted.", methinks you misunderstand.


 * What WP:EL says regarding this is that "[it] does not apply to inline citations or general references, which should appear in the 'References' or 'Notes' section" That is saying that there are things called inline citations and other things called general references which may appear in Wikipedia articles which, if they appear, should appear in the "References" or "Notes" sections of articles; further, EP:EL says that it does not apply to those things, appearing in those sections of articles. WP:EL provides convenience wikilinks to a WP:ESSAY named WP:Inline citations (Please note that Wikipedia essays, such as WP:IC, are project pages on Wikipedia-related topics, but with no official status.) and to the General references section of the content guideline named Citing sources.


 * Re your assertion, "The aim is to get accurate information with the best refs available.", re "accurate information" please read the first paragraph of WP:V (please read the whole thing but, re "accurate information", please pay particular attention to the initial paragraph); re "best refs available" please read WP:DUE.


 * Please read Policies and guidelines. Please look over List of policies and List of guidelines.


 * Regarding the placement of that external link you've placed in the article's lead section, you should be guided by content guideline WP:EL, which says, "Wikipedia articles may include links to web pages outside Wikipedia (external links), but they should not normally be used in the body of an article." you should also be guided by Manual of Style (lead section).


 * As to the rest of it, I'm going to take a breather from this article. I've got to get ready for a flight halfway around the planet beginning tomorrow, and I'm not packed yet. I'll be both jet-lagged and busy after completing the flight. I don't know when I might revisit this article. Wtmitchell (talk) (earlier Boracay Bill) 08:31, 24 March 2011 (UTC)

OK, I'm not a WP lawyer. I will try to look at the the guidelines you indicate (thanks for specific links) but like you I don't much time. However, beyond link formatting worries, it seems the primary issue here is the facts. The main fact is prominent in the article.

I have said repeatedly that this art. needs better refs but no-one seems to be able to find any. ''' The onus is on those wishing to maintain the claim that banana dose has the value stated in the article to provide expert backing for that point. All we have so far is a handbook on nutrition with no page number.'''

What we do have is a credible authority saying the whole idea is not applicable to potassium and why it is wrong. Though several improvements have been made to that this week, a better quality ref for that source would also be good.

For now I have left the oft quoted value for BED, though this seems to be totally spurious and not backed up *any* authoritative source. (nutrition does not cover competence in nuclear physics or the biology of radiation exposure, and it would seems in this case the biology of potassium got missed as well).Climatedragon (talk) 08:51, 24 March 2011 (UTC)


 * I would also suggest you get acquainted a bit more with customs here at wikipedia. also with one of its stronst rules WP:NPOV. What you suggest right now, saying "there are no reliable sources to back it", is removeal of the article.
 * About WP:NPOV calling the concept "flawed" in the first sentence before even saying what the concept is is a very strong judgment. It actually suggests that "being flawed" is its main characteristic - which I don't see. Its main characteristic and reason to be notable is (according to the article) that it has been used in political debates (where it then has drawn a lot of criticism, because of its flaws).
 * As already noted, Boing Boing as a group blog does not qualify as a reliable source. The information there is based on a self-published book from a publisher that is even on a spamlist - a strong indication that things published there do not qualify as a "reliable source" either. I do agree that what he says is actually reasonable (which is the reason, why nobody has removed the quote yet). It's also inappropriate to use direct quotes in the introduction/abstract of the article, which should briefly explain the lemma and summarize the main points of the article. You were not linked to all those documents just for fun or out of spite, but because this article demonstrated in many points a lack of understanding of conventions and rules for wikipedia articles (and articles in any encyclopedia). Cheers Iridos (talk) 10:29, 24 March 2011 (UTC)


 * It does not matter whether Lulu is on the spam blacklist. The book is a borderline reliable source because it was written by an expert. (See WP:SPS.) Reliability and spam are two completely separate concepts and it would be good if everybody here would stop confusing them. Even more importantly, the question whether the book is notable does not even arise because there is no indication that it contains the information.
 * The Boing Boing piece is an interview by the science editor of Boing Boing with an expert. While Wikipedia hasn't yet decided what to do with established group blogs such as Boing Boing in terms of (formal) reliability, it is clear that this is a voice to be taken seriously. Regardless of whether we can use it in the article or not, if we find the point made to be convincing, then this can inform our editorial decisions. If it turns out that all the numbers published in "reliable sources" are in error and are in fact wrong my several orders of magnitude, then we have an obligation not to spread the misinformation further. (In fact, in that case it would be even better to describe it and explain why it is wrong.) Misinformation is not NPOV, even if it is from a "reliable" source and the only source debunking it is "less reliable". I am not saying it is the case. I tried to find out either way but could not make up my mind due to severe paucity of published information that I can access from my university computer.
 * Those who claim that a BED is about 0.1 µSv seem to be extremely economical with any and all details that would help with independent verification of the numbers. In most cases it looks as if they just copied it from somewhere. In one case it looked as if the person who calculated it made precisely the error described by Geoff Meggitt. Let's ignore the article for a moment and find out whether they are right anyway. Hans Adler 12:37, 24 March 2011 (UTC)


 * You claim "The information there is based on a self-published book from a publisher that is even on a spamlist " which I have already pointed out is untrue. The quote was from an interview NOT from his book and any attempts to tie this into the fact that he has published a book using lulu.com is a disingenuous slur in an attempt remove his comment. It seems you got caught by the slur. See above.


 * Previous forms of this page just categorically stated an erroneous value and continued with incorrect comparisons. Up until today most sttempts to correct this error just resulted in it being reverted to what was known to be wrong. No one could be bother to improve, just embarked of silly edit wars. This seems to one of the predominant "wikipedia customs" I have encountered.


 * Now 'frog has made some sensible changes, maybe some progress can be made.


 * There is still no proper source for those who want to put a number on this. But the rest makes more sense now. And at least indicated to the reader that the value seen all over the web is not correctly calculated and why that is so. That's an improvement Climatedragon (talk) 12:33, 24 March 2011 (UTC)


 * Anyone have a copy of CRD Handbook on Rad Measurement and Protection? p640 (in a pre-1995 edition at least) apparently talks about a "reference banana" and runs the usual cals. The entire 1995 discussion on the radsafe list covers everything that's been said here (even homeostasis of potassium) two decades ago. Note that the later 2004 University of Nevada article uses 126g as a "medium sized banana" while in 1995 radlist may have used 150g as the standard banana, resulting in slight different numbers. As for those that doubt that bananas have high enough of a radiation level to trip U.S. port radiation detectors: Don't Go Nuclear Over a Banana Innovan (talk) 21:05, 24 March 2011 (UTC)


 * I believe was can now say Gary Mansfield at the Lawrence Livermore National Laboratory originated the Banana Equivalent Dose on March 7 1995 on the radlist discussion group based on this citation and eliminate Bowes and Church's as a reference. Bowes and Church is cited in the 2004 University of Nevada article for the amount of Potassium per 150g (also conveniently one cup by volume) of raw bananas, but it never origins the BED itself. Innovan (talk) 21:28, 24 March 2011 (UTC)


 * No, sorry, while you are more likely right about this than not, we can't say that he originated the concept because this is a primary source which we can't use in this way. It's entirely possible that he wasn't the first to come up with this idea.
 * But for me it's an extremely valuable source because it has pointed me to Federal Guidance Report #11 as the source of the CEDE factor of 5.02×10-9 Sv/Bq. While this document doesn't say where the number comes from, it has some detailed discussions for other substances for which the value was changed. From these discussions it is clear that the factors are based on approximate models of metabolism. Unless and until another reliable source says specifically that this factor is wrong, we should accept it as correct and discard Geoff Meggitt's argument as not being sufficiently specific. While it is clear that he believed that the calculation did not take homeostasis into account, the objection (at least as filtered through the Boing Boing piece) is not detailed enough to decide whether he was saying that the value in FGR11 is wrong, or just assuming that the BED is computed in a more ignorant way (as the Boing Boing article suggests). Hans Adler 22:46, 24 March 2011 (UTC)

FGR#11 is interesting and gives some insight into how this bureaucratic world functions. A couple of things I noted. The table of p28 shows a good dozen elements (including Ca) where the values changes by well over and order of magnitude from on "model" to the next. The following summary on p29 says: "for about 70% of radionuclides, the differences are not substantial, ie., less than a factor of four.

That points out that none of these figures are derived from actual physical measurements but from computer models. Also there is no qualification on the uncertainty of these values as one would expect if it was a scientific test (which it is not, it's a model). The magnitude of the changes and that fact that a factor of 4 is seen as "not substantial" gives an idea of how reliable the number may or may not be.

http://health.phys.iit.edu/extended_archive/9503/msg00092.html I don't know what the exchange rate for K is, but it is prsesent in signif- icant amounts in the urine, at concentrations that vary comparatively widely. This would suggest, I suppose, that the body regulates K very closely, disposingof excess amounts very rapidly. Perhaps someone should do a study by feeding Reference Bananas to.... [his dots]

http://health.phys.iit.edu/extended_archive/9503/msg00074.html

I have found this "Banana Equivalent Dose" very useful in attempting to explain infinitesmal doses (and corresponding infinitesmal risks) to members of the public. (Interestingly, the anti-nukes just HATE this, and severely critisize us for using such a deceptive concept.)

Would love to go into more detail, but have to get back to our DEADLY Human Radiation Experiments (i.e., eating bananas.)

Considering the fact that the DOE has officially stated that "there is no safe dose of radiation" my advice to you all is to stop eating immediately.

Disclaimer:

Neither Lawrence Livermore National Laboratory, the University of California, nor the Department of Energy recommends eating bananas.

So it seems the advocates of this BED idea do regard it as a bit of an insider joke, and take joy in using it to be provocative.

But if the K-40 in a banana is 400 times more potent than that already in muscle tissue there is still a "substantial" problem somewhere.

At least this is getting closer to understanding where it comes from and how it is calculated. Climatedragon (talk) 07:07, 25 March 2011 (UTC)

Ah! That same doc shows the f1 uptake rate as 1 (100% uptake in lower intestine) and that is why the result is so high. Now that is the response to a small dose of pure K-40. It is not the uptake of a 0.017% K-40 in a bulk of natural potassium. What this poster is doing, is applying the CEDE for a small dose of pure K-40 to the absorption a bulk dose of natural K.

I don't have the definition of the "reference man" they use in the model but this study is designed for evaluating normally low levels of exposure in working environment, not swallowing grams of various radionuclides.

This would explain the difference with Geoff Meggitt's comment. This needs verifying but I think this explains the obvious discrepancy.Climatedragon (talk) 08:24, 25 March 2011 (UTC)

Micromort
The article previously included content a paragraph on micromort. I don't disagree with the removal of that particular paragraph (which failed to relate to the topic except by dubiously including a quantitative conversion factor) but I think it would be good to retain a link to micromort, even if only in a "see also" section. They are related as both are (arguably slightly idiosyncratic) concepts intended to assist people to reason about extremely small risks of dramatic consequences. (Does someone know the more general title for the cognitive bias relating to large numbers etc? Would be useful in phrasing the relationship with micromort, and more generally for explaining from another angle the motivation for BED.) Also, worth listing a couple other examples used for the same purpose, for example that radiation doses are often quoted in terms of numbers of not bananas but medical X-ray proceedures or CT scans or intercontinental flights? (The CT/MRI scans are potentially misleading though, since that kind of dose is avoided except when there are overriding medical motivations, contrasted with something like a dental x-ray done routinely for preventative/explorative reasons..) Cesiumfrog (talk) 01:55, 28 March 2011 (UTC)