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Ask Slashdot: Radiation Detection For Tokyo Resident?
An anonymous reader writes "I'm an American who is living in Tokyo. Stories have started popping up about 'radiation hot spots' in Tokyo and surrounding prefectures so I have begun to worry. I live on the first floor of my apartment building and right by our washing machine there is a gutter out there that is clogged with rain water and mud, which has me especially worried because my wife and I are planning to have kids soon. Obviously no one from the government is going to come by to check our gutter so I feel the need to take matters into my own hands. I have absolutely no idea so I'm asking you guys. What kind of radiation detector should I get? A Geiger Counter? If it measures Gamma rays is that enough? Are alpha and beta dangerous too? I know no one has all the answers regarding radiation but any advice you guys could give me would be great."
Ask Slashdot anything you want! No need for prior research or common sense.
Even the Setagaya hotspot, caused by a forgotten stash of highly radioactive radium, which was orders of magnitude worse than anything else found in Tokyo, was nowhere near the point where it would have posed any danger to the people in the vicinity.
This is just not something which is worth worrying about, much less spending money on. Save your money for the thing your kid actually needs.
Well, what the best device is depends on what it is you want to measure. Alpha particles are not harmful if on the outside - they can't penetrate the skin - but can be exceptionally nasty if ingested. Beta particles can travel further and through more, but still aren't exceptionally dangerous at the kinds of doses you're likely talking about. Even radioactive particles that emit gamma aren't dangerous in low quantities.
The limestone caves in the Peak District are considered dangerous enough that guides can't go down them on consecutive tours and sections are off-limits to potholers. You should probably wait 10-15 mins after going on a tour before getting into a car if there's a group of you. The source of the radioactivity is a mix of uranium-containing ores and radon-bearing igneous rocks. If you were to encounter anything comparable in Tokyo, you'd be in serious trouble,
In reality, the biggest hot-spot reported to date was due to antiques. In all probability, uranium ore (a very popular mineral for adding a yellow tint to glazes and glass in the 1800s and early 1900s) would be what was found, although depending on the instruments used, radon-based paints (very popular for its glow-in-the-dark properties) is another strong possibility. Neither could be considered remotely a health hazard to your average citizen. In fact, given the volcanic nature of Japan, radon-bearing rocks are almost certainly your number 1 health hazard. For that, you'd want a Geiger counter (only if paranoid) and a decent extraction fan (radon is a gas).
If you're worried about fallout, then put a small plastic tray on the roof to collect rain and borrow a Geiger counter. If the rainfall contains nothing of significance now, then it won't do in the future. It takes a LOT to put something as heavy as dust as high up as the cloud layer.
If you are absolutely paranoid, take a roll of 35mm film into a pitch-black room and unroll it. Cut it into squares. Put each square between two pieces of cardboard that are just thick enough that absolutely no light will get through. Use duct tape round the edges to seal the sandwich up. Radioactive dust is the biggest problem and dust is worst in the corners of rooms, since they're hard to clean. Put a film sandwich in all the corners in your house. Leave them there for, say, about a week. Gather them up and take them to anyone with a darkroom to develop. If the squares are completely fogged over, THEN you can worry. And buy a better vaccuum cleaner. If the film shows little or nothing, then you can be absolutely certain that the only thing that you're in danger of is a heart attack from self-induced stress.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
From http://health.phys.iit.edu/extended_archive/9503/msg00074.html:
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re: The Radiation Dose from a "Reference Banana."
Some time ago (when I almost had time to do such things) I calculated the dose one receives from the average banana. Here's how it goes:
On page 620 of the CRD Handbook on Rad Measurement and Protection, the concentration of K-40 in a "Reference Banana" is listed as 3520 picocuries per kilogram of banana. For those of us who are stuck in certain unit ruts, this is equivalent to 3.52E-6 microcuries of K-40 per gram of banana.
An average "Reference" banana weighs (masses) about 150 grams (I think.) So, the ICRP Reference Banana contains about 5.28E-4 microcuries of probably deadly K-40.
Federal Guidance Report #11 lists the ingestion dose (committed effective dose equivalent) for K-40 as 5.02E-9 Sv/Bq or (again, for those of us who are "unit-challenged," 1.86E-2 rem per microcurie ingested.)
Thus, the CEDE from ingestion of a Reference Banana is 5.28E-4 x 1.86E-2 = 9.82E-6 rem or about 0.01 millirem.
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.)
The same table in the CRC Handbook lists 3400 pCi/kg for white potatoes and 4450 pCi/kg for sweet potatoes - so you could carry through the same sort of calculation for Reference Potatoes. Interestingly, raw lima beans come in at 4640 pCi/kg, "dry, sweet" coconut comes in at 6400 pCi/kg, and raw spinach (yum!) comes in at 6500 pCi/kg.
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.
Oh yes! Almost forgot. Regarding K-40, go into your local grocery store, buy some salt-substitute (there are two common brands, and the one in the white and orange labeled container works best) spread some out on a table and check it out with a GM survey instrument. There it is folks, deadly radioactivity in your grocery store!
Yours for healthful diets . .
Captain Internal Dosimetry
aka Gary Mansfield, LLNL, (mansfield2@llnl.gov)
Disclaimer:
Neither Lawrence Livermore National Laboratory, the University of California, nor the Department of Energy recommends eating bananas.
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The point of course, is to make people realize that the notion that "there is no safe dose of radiation" isn't necessarily correct. Your granite countertops have trace particles of uranium in them. The Capital Building in Washington DC has so much granite in it that it wouldn't be qualified as a nuclear facility because it already emits too much radiation. We consume radiation all of the time from a variety of sources and our bodies rid themselves of it naturally.
I was in the park the other day wondering why frisbees get bigger and bigger the closer they get - and then it hit me.
I do not have any information about place where you could borrow one, so I am unable to give any advice on that. What I said was, specifically, "Save your money".
I only just found out about the 57 microSv/h hotspot. That is indeed very interesting, but it is extremely unlikely to have anything to do with Fukushima, and sounds more like buried illegal radioactive waste, or maybe another forgotten stash of radioactive material that got buried by chance. That is something that could be found pretty much anywhere, and if you wouldn't worry about that living anywhere else, you shouldn't worry about it when living in Tokyo. The chances of encountering such a thing are quite minuscule.
Now, having citizens equipped with radiation monitors moving around measuring radiation is actually a very good idea, for exactly this reason: There is a lot of forgotten radioactive material around the world that it would be good to find, and lots of people moving doing lots of measurements helps with that. We saw this already with the Setagaya hotspot. However, this doesn't seem to be what the person asking the question is interested in. He just seems to want to measure radiation around his house, not over a larger area and not coordinated with others. This is basically useless.
I love technology of all kinds. I am also working on a graduate degree in health physics (radiation protection would be the more appropriate title, fyi). Frankly, assuming this isn't someone trolling slashdot, he really shouldn't bother. The fact that he had to ask if alpha radiation was a significant concern tells me he isn't even close to qualified to assess the risks a radioactive source poses.
Think of it this way.. If someone asked you "I want to write my own TV database scraper. What would the best type of programming language to learn be? Will I need a keyboard? Just fyi, I only have a small amount of time, as this isn't my career," what would your response be? The question he asked is on the same level. If you don't immediately recognize that, then you really have no business commenting on the subject. It would be like someone asking for the best statistical thermodynamics textbook, then making it apparent they didn't know basic algebra.
Ignoring for a second the obvious serious lack of knowledge, radiation monitoring equiptment of any quality is expensive and needs calibration. Which requires access to radioactive standard sources. A geiger counter tells you nothing, especially a crappy one. I have a natural uranium deposit not far from my home. A geiger counter would light up like a christmas tree near it. If you didn't understand what what was going on, or even worse, didn't have any understanding past "the needle is moving, oh no!", then the results would be at best worthless and at worst misleading. And in the end someone untrained would have wasted thousands of dollars for no reason.
Believe it or not radiation is a complex and not at all obvious thing. Most people haven't studied it in any significant fashion, in a university or otherwise. In the same way a doctor would never encourage someone to self diagnose, I would never encourage someone to measure radioactive exposure by themseves. It would be irresponsible for me to do so. And excuse all the comparisons, but I occasionally go to public outreach meetings and have become aware that people need things put in terms they understand. Especially smart people. Smart people tend to form an ignorant view, assume they are right, then assume some kind of conspiracy when they are informed they are wrong.
If Mr/Ms Anonymous wishes to contact me, I can check the gutter etc for him/her. I've checked out friends' places in Chiba and elsewhere. Immediately after Fukushima, prices on detectors rocketed past $1200; now they're back down around $300 and in plentifu supply. The cheapest sensible devices available in Japan at the moment are probably one of the Soeks range. This is a detector, not dosimeter. It doesn't log data, and there's no PC connectivity, for example.It only runs 10 hours on a battery, though. For dosimeter, the DosRAE2 is readily available and, again, reasonably priced. It runs 400 hours between recharges and is designed to be worn as a badge. Lots of alarms. The PC software for logging data and managine multiple DosRAE2 badges is laughably bad, though. If you really want one of these things, I'd definitely go for the simple geiger counter (i.e. Soeks), because you get a very visual idea of what's going on around you. Many of the people using these things around Japan aren't capable of interpreting the results. Hotspots within Tokyo: not seen anything comparable to yer average granite lobby, and nothing anywhere near, say, Colorado.
Slashdot is of course on the "pro-nuclear" side
Slashdot has educated people, with backgrounds in science, who understand the issues involved in nuclear processes.
Your implication is that there are two reasonable sides to the argument: pro-nuclear and anti-nuclear. This is akin to saying that there are two sides to the flat earth debate. The only difference is that everyone knows the flat earth people are wrong, but it takes a substantial amount of education to recognize how badly wrong the anti-nuclear crowd generally is.
As for the topic of this thread, the idea of asking for a geiger counter to measure some pool that is probably barely above background (if at all) would be like somebody asking if he needs to buy a set of 11 super-powered turbo fans for his home computer that he uses for email that has been running a little slow lately.. He can buy the fans, and there might be some marginal use to them, but the money would be better spent dealing with real problems.
Yes, I have a background in nuclear physics. No, I don't think it makes me biased, I think it makes me informed.