Banana equivalent dose | Hacker News Reader

Banana equivalent dose

en.wikipedia.org

470 pointssoyelmango84 comments

A number of years ago there was an incident in Sweden where a tiny crack was discovered in a container that had been used to transport nuclear waste from one of Sweden's reactors.

This caused a lot of media attention and some politicians made statements about how this was unacceptable and that they would look into it.

One reporter interviewed an older physicist that worked with radiation protection for the government and asked him if a substantial amount of radiation had been released. He said something along the lines of:

"Well, yes there was a fairly significant amount of radiation, about the same level as you would be exposed to when standing next to several crates of bananas."

This made the media hype seem somewhat exaggerated...

I love the comparison through to three-mile-island. This really goes to show that radiation is so hyped and never put in perspective. Obviously not everyone is a nuclear physicist or even understands this stuff. This is why people should have researched and claimed that the radiation exposure they got from 3mi is the equivalent of ingesting a single banana. It is important to put things in terms most people would understand when you are making a public announcement. Maybe that is asking too much from the media...

Unfortunately, radiation lends itself very well to sensationalism - "Invisible death rays are killing you right now!" That's exactly the kind of thing you would actually, really want to be very afraid of if it were happening, because developing symptoms is the only way a civilian could notice.

But the important part of assessing danger is knowing the strength of the radiation, and most public accounts simplistically divide objects into "radioactive, run for your lives" or "safe". Since measurements can accurately distinguish levels of radiation that are actually indistinguishable as far as real danger to human beings, you get reports like in the link stating that "the milk is radioactive!" when it's only 1/75th of a banana dose and no threat at all.

> Unfortunately, radiation lends itself very well to sensationalism

It's strange, but it wasn't always this way. If you look back into older literature, there was a sense that radioactive things would bring about a bright, promising future. So much so that people did some pretty crazy things (at least, knowing what we know now) like those foot x-rays that shoe stores once gave (which caused some pretty high radiation exposure), or those "health" drinks that got people to drink Radium water a long time ago[1].

But once the problems came to light along with the fears of nuclear war and the demonstration of the power of atomic weapons, radiation became something to be feared, even irrationally much. I really hope that things even out over time, so that we fear it neither too much nor too little. It certainly can be dangerous. There were even some really scary criticality accidents[2] with people working on the cores to nuclear bombs. But at the same time, people point out that we don't have to fear every bit of radiation. After all, there's plenty of natural background radiation all around us, from bananas to Brazil nuts.

I wish that we could come up with a happy medium, but I think it will require a lot of time and education.

[1] If you want to see the Radium water, read this: http://www.popsci.com/scitech/article/2004-08/healthy-glow-d...

[2] The "walking ghost" phase after massive exposure is especially creepy. More info here: http://en.wikipedia.org/wiki/Criticality_accident

OT, but interesting factoid about TMI:

TMI-2 was built on the final approach path to Harrisburg International Airport, a former U.S. Air Force base, and was therefore beefed-up specifically to withstand the impact of a B-52 hitting the structure at 200 knots. A normal containment [vessel] would have been breached.

http://www.cringely.com/2009/03/three-mile-island-memories/

I think the media's exaggerated response to tiny nuclear leaks is, however, one case where I'd prefer media hype to put the pressure on the industry to over-engineer their containers.

The consequences of breaking open (not just a tiny crack) a crate of bananas and a container of industrial nuclear material are probably many many multitudes apart.

I'll bet that more people have been killed in the last 10 years by falling crates of bananas than have been killed by leaking nuke containers.

Yes, there are far more crates of bananas. My point is that we should make these decisions with cost-benefit analysis, not hype.

How do you weigh the benefit of not killing unaware people against the benefit of not killing people? At least banana loaders know they're in some danger, and have probably analyzed the cost of that against the benefit of a larger pay.

Six months ago you could have made the same claim about blowout preventers. Extremely rare catastrophic failures can cost a bundle. In many cases you may not even be aware of the risks or the potential costs before you first encounter them.

More nuclear power is the future, at least in the near term, but we should have the humility to admit we don't really understand all the risks and all the costs.

We also don't have enough resources to protect against every imaginable risk, which six-months ago, is all the current oil disaster could have been: imagined.

It still makes more sense to spend attention and resources protecting us from falling crates of bananas if those are more harmful in reality.

But fear normally wins these battles, like with terrorism. Automobile accidents kill about 36,000 people[1] per year in the United States. That's 12 times the number[2] of people killed in the 9/11 attacks. Which one of those do you think we're spending hundreds of billions on?

1. http://www-fars.nhtsa.dot.gov/Main/index.aspx

2. http://nymag.com/news/articles/wtc/1year/numbers.htm

>... every imaginable risk, which six-months ago, is all the current oil disaster could have been: imagined.

Ahem:

http://www.liveleak.com/view?i=127_1274931222

I don't know, how much goes into transportation in the US? I mean, aside from the vehicles, including researching new tech for safety, advertising those features, law enforcement of safe driving laws, DMV money, roadwork, and whatever else goes into it. It seems like a lot to me.

Another thing to think about is that maybe we're hitting the safety cap in automobiles. Maybe the cost of making things more safe nowadays is just way too high. It could be that the cost of going after some terrorists is even higher, but we might not have been so sure at the time.

Also, the problem with ignoring people who set out to murder you is that it shows an unwillingness to do so. It might prompt other would be killers to attack. A car, on the other hand, isn't going to notice all the accidents happening, and choose to crash because of them.

>Also, the problem with ignoring people who set out to murder you is that it shows an unwillingness to do so.

Terrorism is not about murdering people. It's about pushing people like yourself to overreact.

Terrorism is pretty much about murdering people. If you're talking about the motive for terrorism though, I didn't mention it, so I don't know why you would try to contradict me on something I never mentioned.

Also, what are people like me? And what is a proper reaction to an organized attempt to kill civilians in your country? I do not suggest that the US took the proper course of action, btw.

> Terrorism is pretty much about murdering people.

No. Terrorism is, by definition, about using fear as a weapon to further your goals. Terrorism can be perfectly successful even if nobody dies -- it's all about playing your opponent's need to react against him. That's why even a fake bomb, or pre-announced bomb attacks IRA style are terrorism -- because there has to be a reaction to a bomb threat, at a relatively small cost a terrorist can force the opponent to do huge evacuations and bomb sweeps.

Completely ignoring the 9/11 would have been a better reaction that what the USA took -- but as usually with well planned terrorism, completely ignoring the attack would have been politically impossible.

> And what is a proper reaction to an organized attempt to kill civilians in your country?

A proportioned response against the attackers, instead of some of their various allies or complete third parties.

Expand that to 60 years and you include Japanese who suffered long term radiation problems and birth defects as a result of Hiroshima and Nagasaki, not to mention Chernobyl and those who suffered as a result of depelted uranium munitions in both Gulf Wars.

On the last point:

http://www.seattlepi.com/national/95178_du12.shtml

Over x10 increase in Iraqi birth defects from 1989 - 2001:

http://www.wsws.org/articles/2005/may2005/iraq-m10.shtml

I think giving lethal doses of radiation is an important part of what a nuke is supposed to do (which is mostly to terrify the other side).

As for Chernobyl, it was significantly underengineered and negligently operated, something clearly indicated by the fact no other comparable nuclear accident happened, before or since.

And depleted uranium ammo... well... that's what you get when you use something toxic (depleted uranium is toxic even if it's not that much radioactive) to make your ammunition.

It wasn't merely negligently operated. The safety was turned off for tests. Effectively, it was the equivalent of sawing off your brake pedal and driving full speed into a wall to see if the airbags hold. With known-faulty airbags.

The only point I was making was in response to the comment above where the commenter was downplaying the effects of radiation poisoning causing huge amounts of human suffering and death. I was merely pointing out that there has been a lot of hardship caused by both nuclear weapons, DU and nuclear accidents - read the second link above, and account of a guy who was sent to clear up DU after the first Gulf War. Pretty horrific stuff.

Both the radioactive fallout of a nuke and the toxicity of depleted uranium are features rather than bugs. Those things are designed to be as lethal as possible.

OTOH, in the specific case of the depleted uranium, it could be possible the extra lethality was only a happy accident.

Weapon designers are an interesting breed.

Part of the problem with objective cost/benefit analysis in the case of nuclear exposure is the history of government deception about the risks of nuclear experiments. All that lying has made people very distrustful of both scientists and the government.

I found

http://mitpress.mit.edu/catalog/item/default.asp?ttype=2&...

to be a revelation in this regard. It's about the uses and abuses of the Nevada test site over the 1950s. From the summary:

"In the late 1950s, birth defects and deaths from cancer began to soar among civilian and military test-site workers and their newborn children, and among "downwinders" living in Nevada, Utah and other western states. Gallagher, a professional photographer, spent several years interviewing and photographing these nuclear-test victims and gathering evidence of official indifference, callousness and outright cover-ups. The sheer density of suffering depicted here is awesome; in certain Utah towns, for instance, Gallagher found cases of cancer in every house. The bitter, stoic testimony of the victims (many of whom have since died), accompanied by Gallagher's photographic portraits of them, is deeply disturbing and exposes a major national scandal. "

I think hype does far more harm than good. It tends to produce blanket opposition to nuclear power rather than pressure to do it well. And nuclear facilities are already over-engineered. What we need is calm examination of the risks and benefits, not hype.

Yes, but you should put equal pressure on other industries that do as least as much harm. E.g. coal burning power station release more radioactivity [1] into the atmosphere (and other worse stuff) than nuclear power plants.

[1] Coal contains some radioactive elements, and they are burning so much coal, that it gets significant.

Its easy to cause hysteria over things one can't have one of the few senses to grasp. Radiation has no taste, smell or other subjective graspable metric. Thats how you can play on it and media knows it, as good writers do.

From now on, all small leaks should be denoted in crates of bananas. 1x1 meters in size.

I wonder at how many bananas my WRT54Gs radiates...

Radioactive output of Chernobyl = 140e6 curies [1]

Output in picocuries = 140e6 * 1e12 = 1.4e20

Picocuries per kg of bananas = 3520

Radioactive output of Chernobyl in kg of bananas = 1.4e20 / 3520 ~= 4e16

(for reference, the weight of the Earth ~= 6e24 kg [2])

1: http://archive.greenpeace.org/comms/nukes/chernob/read25.htm...

2: http://www.wolframalpha.com/input/?i=weight+of+the+earth+in+...

Neat, but misses the point.

Not really. One thing missing from the article is the banana equivalent level for more serious radiation concerns, such as the banana-equivalent of a chest x-ray or radiation poisoning. Otherwise, when someone hears, for example, that living within 10 miles of a certain nuclear plant is equivalent to eating a banana a day, they may well conclude that both the plant and bananas are serious health risks.

Ah, good point.

I was thinking more along these lines: the purpose of talking about "banana equivalent doses" is to make otherwise meaningless numbers easier to understand by relating them to everyday experience. The comment by m0th87 doesn't really do that. "40000000000000000 kilograms of bananas" is just as difficult to comprehend as "140000000 curies".

So to relate serious radiation back to bananas, let's say that Chernobyl released as much radiation as worldwide banana production[1] for the next 55,000 years.

[1] http://en.wikipedia.org/wiki/Bannana#Trade

> 140000000 curies

I gather 140000000 curies means something like "how many is the least of your problems"

This seems like a useful way to decrease concern about radiation exposure, but I think it causes the reverse problem. There is no size of banana-pile that I would consider dangerous. I would never think, "Well, that's as dangerous as a pile of 5 million bananas! Holy shit! Break out the lead suits and the iodine pills!"

Edit: if you believe the Wikipedia page on röntgen equivalents in man, it would seem that 100 rems "will cause illness," which, if I did my math ("maths" in the UK) correctly, is equivalent to eating around 10,000 bananas. It's not clear how much safer it is if you're not eating the bananas, but merely sitting near them, juggling them, or bathing in their puree.

> 100 rems "will cause illness," . . . equivalent to eating around 10,000 bananas

Well, those numbers are for acute exposure, so you would have to eat them all at once. In which case, I'd think the 1.2 million calories would also be a concern.

I'm thinking that 10,000 bananas in your stomach at the same time would be an even GREATER concern.

if I did my math ("maths" in the UK) correctly, is equivalent to eating around 10,000 bananas.

I think the number of bananas is actually higher:

100 rems * (1000 millirems / rem) * (365 bananas / 3.6 millirems) = about 10,000,000 bananas

Oh shit! Even worse! Break out the lead coffins!

Man, I should get better at math ("maths" in the UK).

When I worked at Brookhaven National Lab, the sewer system had radiation detectors in it, to ensure there was no improper disposal of radioactive stuff. It was said that it was sensitive enough to detect someone flushing a banana down the toilet.

The Assistant Director of the lab at the time, had had a radionuclide angiography, and I guess the radio marker is emitted in the urine, because he claimed to have set the alarms off after coming back to the lab post-procedure.

I hear plumbers aren't too fond of that.

This reminds me of a story about my wife. She worked in a hot-lab at the time, using P-32, and she was extremely fastidious about using the Geiger counter to ensure she never spilled any material on the bench or equipment.

Then, one day she calls me to her lab, and I can tell she's very frantic. I rush up the 3 flights of stairs and into her lab and ask what's wrong. She was worried that she had spilled the raido-isotopes because the Geiger counter was picking up counts all over! The lab bench, the pipettes, the Eppendorf tubes, everything seemed to be hot. I paused for a moment, then took the Geiger counter from her and pointed the probe at her. The needle JUMPED to the max and she turned flush white...

...the day before she had undergone a stress test with a Technetium tracer.

Possibly apocryphal story that supports the assertions of BED, I read somewhere long ago that the Monticello nuclear power plant sheds less radioactive stuff into the Mississippi river than the water treatment plant 100 miles downriver at Pigs Eye in St. Paul because of flushed medical diagnostic residues. Off topic: around the same time I read that there's a statistically significant difference (a rise) in the level of caffeine in the Mississippi as measured above and below the Twin Cities.

One thing to keep in mind vis-a-vis radioactive iodine is that it tends to concentrate in the thyroid, whereas potassium is distributed pretty evenly and excreted quickly.

I'm really surprised no one else is discussing this point. The article says that potassium stays mostly in solution in the body, which means that regardless of how many bananas you ate (or anything else with high levels of potassium) your body is just going to excrete most of it.

So there is no real comparison to make between bananas and any dose of gamma+beta radiation, making the whole "banana equivalent dose" at best mistaken and at worst willfully misleading.

> So there is no real comparison to make between bananas and any dose of gamma+beta radiation

Why is that? Let's say you receive a millirem by standing close to a nuclear power plant core. Then you eat a banana, which spends one day in your body before the potassium is excreted, giving your body one millirem of radiation in the process. What's the difference?

I'll agree for iodine ingestion however. They could consider the radiation emitted over a human lifetime to be fairer.

The article says the banana equivalent dose concept was intended to ridicule people who were afraid of nuclear power plant accidents. Such accidents would expose people to radioactive iodine, which, in the article itself says: "The combination of bioaccumulation and the greater penetrating power of ionizing Gamma radiation makes radioactive Iodine significantly more hazardous to humans than equivalent amounts of Potassium-40".

So no, being in the vicinity of a nuclear accident at dose X of Gamma + Beta radiation in the form of iodine that is going to be absorbed into the thyroid (leading to continued further exposure) cannot be meaningfully compared to the same dose of just Beta radiation from potassium that is passed through the body and excreted.

My point is that gamma/beta radiation is not "in the form of iodine". Iodine releases radiation; this radiation is the same, wherever it came from.

Gamma and beta radiations can in fact be meaningfully compared on their effect on the body. The nature of the rays is taken into account when calculating the rem dose. See the radiation quality factors: http://www.nuclear.utah.edu/class_notes/5700/sup_9.doc

The BED cited by wikipedia (3.6 millirems for eating one banana a day for a year) is equal to .000036 Sv. Will you get chronic radiation sickness from that? Not even close. Chronic exposure to radiation in the 0.4 Sv range--over 10,000 bananas per day--is not enough to cause harm, and actually appears to be beneficial.

http://cerrie.org/committee_papers/INFO_14-C.pdf

For those wanting to learn more about nuclear power, from uranium mining to how power plants work and how they are operated (the logistics of them), I recommend:

Power to Save the World: The Truth About Nuclear Energy by Gwyneth Cravens.

She spent almost a decade doing the research for this book with lots of help from a physicist who works on nuclear safety at a US lab (forgot which one). She used to be an anti-nuclear activist, but gradually changed her mind during the process of writing this book.

I propose a larger unit of measure: the Chernobyl Sheep Equivalent Dose. This is based on a 50kg sheep at the upper allowable limit of 1000 Becquerels per kg. http://en.wikipedia.org/wiki/Chernobyl_disaster_effects#Food...

Converting our Banana Equivalent Dose of 520 picocuries. 1 Bq (Becquerel) = one radioactive decay per second. 1 Ci (Curie) = 3.7 * 10^10 Bq. 520 picocuries = 520 * 10^-12 Ci = 19.2 Bq. Our 50kg sheep = 50 * 1000 = 50000 Bq.

1 Chernobyl Sheep Equivalent Dose = 2600 Banana Equivalent Doses.

Hopefully I got my sums right.

But that undermines the main point, which is to allow non-experts to evaluate the risks by using units they can understand. The general public does not understand Chernobyl Sheep; they DO understand bananas. If you say a leak was the equivalent of 200 bananas, then people can tell whether that's a reasonably size to be seriously concerned about.

And depending on how it's reported, it might also be possible that instead of reassuring the general public, reporting radioactivity in banana units might decimate sales of bananas.

Indeed. If people on Hacker News are responding to this news with a newfound fear of bananas (which several comments in this thread seem to indicate), I can only imagine how the general public would react.

Can they? The BED is radioaction from an ingested banana. I can tell 4 bananas eaten isn't very worrisome, but I've never really seen anyone go above it. I have very little understanding of the effects of eating 200 bananas, besides probably dangerous bloat.

200 BED is just a large number. The BED is great for putting small doses into perspective, but for slightly larger ones I'd need a different frame of reference, such as first lethal dose.

Smugglers: hide your uranium in shipments of Brazil nuts.

I'm not trying to make a joke. That seems (to me, at least) as though it'd be a pretty solid way to defeat import security, which might be some cause for concern.

The worrying part of this joke is that it seems (at least to me) quite possible that this method could allow someone to smuggle enough of some radioactive waste product to make a not insignificant "dirty bomb".

Or possibly to make a dirty bomb by refining brazil nuts.

Fortunately, newer detectors can catch this and separate the bombs from the Brazil nuts.

IANANP, but very sensitive germanium semiconductor detectors, and certain scintillation detectors (sodium iodide (NaI), etc.) can be used to determine isotope type at a distance by gamma-ray spectroscopy.

Fissile material (plutonium or uranium in particular) can also be very effectively detected through neutron emission measurements, but this depends on pricey helium-3-based detectors. In these detectors, thermal (low energy) neutrons from radiological material are captured by He3, causing the He3 to split into hydrogen and tritium (H3) and the release of a gamma photon. The gamma photons can then be detected by traditional means, and the photon counts can be related to neutron flux. Flux measurements can then be used to (hopefully) determine the type of neutron source.

n + 3He → 3H + 1H + 0.764 MeV

The problem with He3 detectors is that the gas has a very low natural abundance, and is accordingly expensive. Most of the current He3 stockpile originates from decaying tritium present in nuclear weapons (~5% of the tritium decays to He3 each year). It can also be manufactured by creating tritium in a reactor and waiting for it to decay. Tritium production is expensive though, as the process requires high-neutron flux bombardment of a boron, lithium, or nitrogen target.

Ok. Exposure equiv to 1 banana. Sounds innocuous. But, is that 1 banana per day, hour, minute, per walk by the contaminated creak? And, for folks living near/in contaminated area with say 2 beqs a day. Has there been any studies of radiological health effects of "eating" 2beqs a day for 365 days over 10 years.

This measurement unit swings too far in the other direction of making radiation sound safe and tasty.

Radiation exposure is cumulative, every bit damages dna/cells even if only a little. I stopped eating Brazil nuts as a kid due to radiation amount. Now considering limiting banana to 1-2week instead of 1-2 day I eat now.

There's no need to cut down on bananas - simply wrap the banana in a thin layer of lead before ingesting. Seriously though, you could be hit by a bus tomorrow; eat the dang bananas.

Actually, there has been a study done, and a fairly statistically robust one at that. There appears to be no cause for concern if you do the math.

http://news.ycombinator.com/item?id=1430003

The radiation hormesis effect:

http://en.wikipedia.org/wiki/Radiation_hormesis

Potassium in a banana: 400 mg. Recommended daily intake of potassium: 3500 mg.

Don't try so hard to avoid radiation sickness that you wind up malnourished.

More to the point: Bananas are radioactive precisely because of the large amount of potassium they contain -- naturally occurring potassium contains a radioactive potassium isotope. You must consume some amount of radioactive material as part of your daily potassium intake regardless of whether it comes from bananas or other food sources.

Brazil nuts are another matter, as they are radioactive because they contain radium, which your body doesn't need.

And I just can't help but thinking... "Aha. So that's where the Bananaphone song got its superpowers from!" ><

On a more serious note, I do love everyday comparisons that everyone can understand. For example, science books for kids measuring things in elephants or houses. It's a comparison they can understand. It's like scaling things down for your brain. They're good tools to detect nonsense, too. Take antivaccinationists. For example, they do talk a lot about "toxins" in vaccines - like formaldehyde. Sounds dangerous, doesn't it? Except... That the average pear has about fifty times the formaldehyde in it, and formaldehyde is naturally present in your body in the first place. Then there's the mercury preservative mostly gone from vaccines anyway - gone in a matter of days, since ethyl mercury is easily passed. The methyl mercury from that tuna salad you ate a month ago is still in your body. But when a non-scientific person just hears "mercury" or "formaldehyde"...

Speaking of having fun with radiation. I've never had the opportunity to point a geiger counter at the stomach of someone who has just eaten a banana, but I have "tracked" through walls and around the corner a co-worker who had just taken radioactive iodine(to destroy his thyroid). Good times.

Wait, why would someone deliberately take radioactive iodine to destroy their thyroid?

Ahh, this reminds me of when wikipedia used to have a "list of ridiculous measurements" page.

I'll have to see if I can find this page in google's cache - I'd be curious to see how many of those 'ridiculous measurements' were really ridiculous, or whether they served a similar purpose to the BED; to allow the average person to understand unfamiliar things in everyday terms.

Found a copy!

http://www.indopedia.org/index.php?title=List_of_strange_uni...

That page has a link to the World Snail Racing Championships as a reference. The web is marvellous.

It always makes me happy that Smoot ended up being the ISO president.

He retired from the ANSI in 2005, and did an NPR interview http://www.npr.org/templates/story/story.php?storyId=5043041; I made sure to wander across town and across the Harvard Bridge the next day, in honor. It’s great that they still repaint the numbers from time to time (annually?).

The relevant Wikipedia articles are:

http://en.wikipedia.org/wiki/List_of_unusual_units_of_measur...

http://en.wikipedia.org/wiki/List_of_humorous_units_of_measu...

Thanks for the link! I'm surprised how many of the unusual measurements I take for granted, even though they're imprecise.

Ha... "New York Second

Theoretically the shortest period possible in Quantum Time, this is the time that elapses between a Manhattan traffic light turning green and the taxi behind you honking its horn"

A better idea might be more education on how radiation works and what kind of radiation is coming from the leak/crack/banana etc. At least in the US people are extremely ignorant of how radiation works and how it can make you sick.

"Chernobyl's radiation was detectable across Western Europe. Average doses received ranged from 0.02 mrem (Portugal) to 38 mrem (portions of Germany).[2] For comparison sake, the dose received from eating one banana per day for one year is roughly 3.3 mrem." http://en.wikipedia.org/wiki/Chernobyl_compared_to_other_rad...

Wow... Who knew that eating one banana a day for a year could give a false alarm on a radioactivity detector?

However much science and practical use the radioactive bananas have behind them, this really made my day.

"Banana equivalent dose (wikipedia.org) 420 points by soyelmango 19 hours ago | 74 comments"

I wonder if I'm the only one who saw that, didn't read the article, and thought "Did some stoner just hack HN?"

how dense should banana jam be to start a chain reaction?

Donkey Kong's origins explained! http://x93.xanga.com/6f5f9254c2234259950277/z207033998.png

Whoa I just ate one. Shouldn't I be getting super powers soon?

Yet another reason why bananas are the Athiest's Nightmare

? What do you mean? I'm not sure how that makes sense, Particularly considering that the modern banana is largely a product of human bio-engineering and has very little resemblance to a wild banana.

It was a reference to Ray Comfort: http://www.youtube.com/watch?v=Y4yBvvGi_2A

I forgot to use sarcasm tags

Note to self: smuggle nuclear weapons underneath a pile of bananas.

Or at least draw a picture of it because of how hilarious the premise is.

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