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Ask Slashdot: Radiation Detection For Tokyo Resident? 371

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."
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Ask Slashdot: Radiation Detection For Tokyo Resident?

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  • by Kagura ( 843695 ) on Friday October 21, 2011 @07:37PM (#37800128)
    Ask Slashdot anything you want! No need for prior research or common sense.
  • Save your money. (Score:5, Insightful)

    by Goaway ( 82658 ) on Friday October 21, 2011 @07:39PM (#37800148) Homepage

    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.

    • Re:Save your money. (Score:4, Informative)

      by EdZ ( 755139 ) on Friday October 21, 2011 @08:26PM (#37800516)
      Additionally, any equipment sensitive enough to detect the trace amounts of radiation above background in a reliable manner is a) going to be rather expensive and b) need regular calibration (in the correct manner) to produce reliable and accurate results. The latter is the main reason why the whole 'citizen radiation map' thing differs wildly from the IAEA figures: buying a cheap GM tube off ebay is not the path to accurate measurements upon which health decisions should be based.
    • by Idou ( 572394 ) on Friday October 21, 2011 @08:27PM (#37800520) Journal
      If this were any other topic that required technology, the majority of highly modded posts would point to various resources on how to approach the technology. Some posts would even include first hand accounts. However, if it is dealing with nuclear power, which apparently the majority of Slashdoters are completely sold on, the highest modded posts are, "don't bother." Any ideas on the discrepancy? If you LIKE the technology, then shouldn't you be trying to get more people involved? What geek hasn't wasted $300 on some device they didn't really need? Why is it not worth it this time and who are you to judge that for a fellow geek?
      • by Goaway ( 82658 )

        If you LIKE the technology, then shouldn't you be trying to get more people involved?

        "The technology" is, in this case, radiation detectors. Now, it is true that I like radiation detectors quite a bit. However, I also realize they are expensive, hard to use, and of little to no value to the person asking the question, and thus the only advice I can honestly give is to not bother, as he would be throwing his money away based on a misunderstanding.

        • by Idou ( 572394 ) on Friday October 21, 2011 @08:41PM (#37800618) Journal
          Alright, why not advise that he BORROWS one from an organization then? Like from Safecast []?

          And what misunderstanding? Maybe he has a kid that likes to play and eat mud and he noticed the 57 microSv/hr hotspot in Kashiwa []. Who knows wtf is going on around Tokyo, but woudn't a legitimate geek response be to scientifically test the area, just in case? Your response is either non-geek like (for a geek site) and/or just playing "nothing to see here, folks" shill-speak.
          • by Goaway ( 82658 ) on Friday October 21, 2011 @08:48PM (#37800676) Homepage

            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 was actually excited about the possibility of constructing a bomb out of some explosives and Tokyo mud. Talk about a dirty bomb!!!! (Dear FBI, I'm kidding, everyone knows you use the contents from old smoke detectors - still kidding!!!)
        • by Ruie ( 30480 ) on Friday October 21, 2011 @11:49PM (#37801630) Homepage

          If you LIKE the technology, then shouldn't you be trying to get more people involved?

          "The technology" is, in this case, radiation detectors. Now, it is true that I like radiation detectors quite a bit. However, I also realize they are expensive, hard to use, and of little to no value to the person asking the question, and thus the only advice I can honestly give is to not bother, as he would be throwing his money away based on a misunderstanding.

          Radiation detectors are not that expensive ! You can pick up old ones on the cheap, or get a new one for $300.

          A few pointers:

          • There are radiation detectors that measure alpha, beta and gamma depending on what shield is on top of the geiger counter.
          • The sensitivity of the detector depends on the volume of the geiger tube. Large ones (pancake, for example) are more expensive.
          • Most of the radiation is not that harmful, and the real danger comes from what manages to get inside, such as with food.
          • It is hard to figure out whether the food is dangerous with a regular detector as you need to integrate data from a high-sensitivity detector over a long time to be sure. This is also why a radon check takes tens of hours to do properly.
          • A sane thing to do with your own detector is to note the level of background radiation usual to where you live and check for any increases. There is usually variation depending on the time of the year (especially with a gas heater), weather, etc.

      • However, if it is dealing with nuclear power, which apparently the majority of Slashdoters are completely sold on, the highest modded posts are, "don't bother." Any ideas on the discrepancy?

        Yes, the answer is this is a "side of the room" problem. It's essentially a form of tribalism. A "side of the room" problem is where a complex issue is divided into two sides, with no room in between. Each group tries to enforce a strict, and narrow viewpoint. Anyone outside of this narrow point of view is simply ign

        • by Knave75 ( 894961 ) on Saturday October 22, 2011 @01:45AM (#37802048)
          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.
      • by Troggie87 ( 1579051 ) on Friday October 21, 2011 @09:21PM (#37800890)

        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.

        • Re: (Score:3, Interesting)

          Personally, I thing ignorant people *should* be learning about and experimenting with radiation detection equipment. The lack of understanding causes a huge amount of trouble, and this is how people learn. And telling people that they are too uneducated to ever understand this stuff is exactly why the public refuses to trust us when we say that they don't need to worry about Fukishema unless they are next door.

          What they need to be told at the same time they start to measure radiation is Don't Panic. The g
      • Re: (Score:2, Informative)

        by Anonymous Coward

        You have this wrong. When people have asked questions where the answer is "don't do it", people have said "don't do it.". That is the right answer in this case.

        First, if someone said, for instance, "What 8-core server do you recommend for me to run my personal web site on?" The answer would also be "Don't bother." Same here. People have hysteria over "radiation", when low levels are simply not harmful.

        Second, there just isn't

    • Re:Save your money. (Score:5, Informative)

      by Kyusaku Natsume ( 1098 ) on Saturday October 22, 2011 @01:00AM (#37801920)

      If he lives in eastern Tokyo metropolitan area there is a slim chance that he indeed have something to worry about like in Chiba or in Saitama. If he lives in western Tokyo he doesn't have absolutely nothing to worry about. Levels in Tokyo in practical terms are at the same level than before the disaster. It would have been helpful if the poster wrote in which zone lives. The MEXT readings in the previous format put Bunkyo-ku as Tokyo's ward with the highest readings, but still not something to worry about.

      Now, the most update info is here: []

      Still, I liked more the previous graph version that MEXT had under prime minister Kan since it clearly put visual info about the highest levels recorded by prefecture, the normal recorded levels and the current levels.

  • by CrimsonAvenger ( 580665 ) on Friday October 21, 2011 @07:41PM (#37800166)

    When they talk about "radiation hot spots", they're not talking about anything that will be a problem unless you're standing on it 24/7 for a decade or so.

    But, to provide more detail, alpha isn't a problem unless you eat the emitter (or inhale it), beta isn't a problem unless the emitter is in contact with your bare skin, and gamma can be a problem, assuming you live next to it for a while....

    If the muddy spot bothers you, hose it off.

    And good luck with the kids....

    • People don' t eat mud, right!? Neither do people eat radioactive caesium, strontium, or plutonium. See, no problem! Man and radioactive isotope can peacefully coexist!
    • by Animats ( 122034 )

      alpha isn't a problem unless you eat the emitter

      True, but that's usually the problem - alpha emitters getting into air or food. A gamma emitter big enough to be a hazard is easy to detect and tends to be noticed. [] Japan has a decent monitoring system, and the US has a paranoid one since 9/11. (Back in 1983, there was an incident where a scrapyard in Mexico got a big cobalt-60 radiation source [] and recycled it into steel. Radiation detectors then went in at US border crossings.)

      Monitoring milk is a good check for airborne radioactives, because cows conc

    • by sjames ( 1099 )

      Actually, most of the hot spots wouldn't be a problem if you stood on them for life. The radiation measured was lower than background in other places.

  • Android app (Score:4, Interesting)

    by Anonymous Coward on Friday October 21, 2011 @07:47PM (#37800214)

    There is an app for that: - and no, it's not one of those fake geiger counter apps, but instead a clever hack using the CCD of the internal camera for detecting beta and gamma radiation. All you have to do is cover the camera, so only radiation events will show up on the CCD. The app counts the events and checks against an established calibration table.

  • I don't know about a radiation detector, but I do have some entertainment suggestions for your music player, assuming of course that it doesn't get fried by the radiation...

    "Christmas at Ground Zero" [] by Weird Al

    "Hot Frogs On The Loose" [] by Fred Small

    On a more respectful note, there is also Small's "Cranes Over Hiroshima" [].

  • Safecast (Score:3, Informative)

    by Idou ( 572394 ) on Friday October 21, 2011 @08:01PM (#37800318) Journal
    You should contact Safecast []. I believe they will even lend you a device and the data will be incorporated into their map.

    Oh, yeah, and you asking Slashdot this question is like asking PETA how to skin a deer. Hope you have the persistence to scan through all the highly modded posts insulting your intelligence to actually find useful answers to your question . . .
  • by rubycodez ( 864176 ) on Friday October 21, 2011 @08:02PM (#37800322)
    Rather than geiger counter, there are plenty of electronic pocket dosimeters which can also show accumulated dose. Your main concern is measuring gamma. These dosimeters will run from $200 to $600 for a basic model. Some even can show dose rate graph over time. []
  • There are some bulky Geiger counter wristwatches you can buy. Polimaster makes some, for example. They're pricey, but they'll do that job. An alarm goes off if it detects too many Sv, which you can set after establishing a baseline for where you live. Since it's a small counter, it takes about a minute for it to accumulate enough statistics to warn you.

    Just never take the thing on a flight. It'll beep without end at high altitude. If you explain why it's beeping, you'll be detained.

  • Measurement (Score:5, Informative)

    by jd ( 1658 ) <> on Friday October 21, 2011 @08:09PM (#37800358) Homepage Journal

    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.

  • Forget it (Score:5, Informative)

    by gweihir ( 88907 ) on Friday October 21, 2011 @08:15PM (#37800408)

    You cannot do this at home. The equipment you can afford (and use) will basically be able to tell you when to run, but that is it. Radioactive substances have highly different toxicity and the direct radiation effect is often not what counts. Example: Plutonium is completely harmless unless ingested. You skin shields completely against its radiation. However when ingested, if comes close to cells and becomes the most deadly substance known to mankind. Also, air happens to shield its radiation! So measuring it requires a very, very thin layer of the substance to be measures, or better vacuum. And very specialized and expensive equipment.

    I advise to invest the effort instead in healthy living. If you can, move far away from Tokyo. Other than that you best bet is to hope for the best.

    • I asked about this on here not too long ago and was advised that the actual test procedure is to have a fan, and a filter, and to test the filter for particles. It seems to me like you could put a remote sensor in a little wind tunnel with a fan at the back and a filter at the front. You can buy an aerosol cleaning spray intended to remove radioactive particulates from the sensor, but you can also just put it in a plastic bag to prevent it from becoming contaminated itself. You can get medical grade air fil

      • by gweihir ( 88907 )

        You actually have to incinerate that filter to measure what was caught in it.

        On the Geiger-counter edge, a normal Geiger-counter does only measure count, not intensity. Yet intensity is critical to identifying what you actually have in your sample. A count of alpha or Beta particles or Gamma rays does not tell you a lot. It basically just tells you "get out here fast" if it is high. The second problem is that Geiger-counter tubes change over time. So what you actually do in a real measurement is first calib

    • by jtara ( 133429 )

      Well, TLDs are cheap. It's just the equipment to process them that's expensive! They're the first-line monitoring device in nuke power plants. Employees where them on the job for a month, and they get turned-in. []

      I think the OP was more interested in a survey instrument in order to test suspected hotspots, though.

      "fleas" might be a problem. I was surprised to find they showed-up in California not much after the accident. San Onofre had a flea problem whe

  • by TwineLogic ( 1679802 ) on Friday October 21, 2011 @08:18PM (#37800420)
    As others have noted, ingesting the material is hazardous. This includes inhaling the material. Wear a face filter if dealing with anything suspicious like that. Otherwise, consider putting on rubber gloves with the mask, and removing the gunk from the gutter to somewhere safely away from you.
  • by riptide_dot ( 759229 ) * on Friday October 21, 2011 @08:27PM (#37800522)
    From []:

    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, (


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

    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.
    • by tg123 ( 1409503 )

      ....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.

      That has to be the best way to trivialise the argument I have ever seen. :-)
      um but we aren't talking about bananas and granite here we are talking about people and are you able to defend
      your argument better than just talking about and hiding behind the trivial ?

    • by bcrowell ( 177657 ) on Friday October 21, 2011 @09:59PM (#37801114) Homepage

      (Interestingly, the anti-nukes just HATE this, and severely critisize us for using such a deceptive concept.)

      Well, that might actually be because you have your facts wrong. BTW, I have a PhD in physics, my specialty is nuclear physics, I am very much in favor of nuclear power, and I think the radiation issues at Fukushima were ridiculously overblown. But nevertheless that doesn't affect the reality that your facts are wrong.

      The body has systems that regulate the amount of potassium it holds. If you ingest more potassium, your body immediately detects that and immediately excretes the excess in your urine. Therefore ingesting a banana has essentially no effect on your radiation exposure. For a very short time, you have a slightly higher than normal amount of potassium in your body. Then it goes back down. The integrated excess dose turns out to be negligible compared to natural background.

      If you want an example that's scientifically correct, here are some:

      sleeping in the same bed as someone else for one month = .001 mSv (not that this will be an issue for slashdotters)

      eating a pound of Brazil nuts = .001 mSv

      long plane flight = .1 mSv

      CT scan = 10 mSv

      dose needed to cause mild radiation sickness = 1000 mSv in a short time

      maximum excess rate of exposure for people in Tokyo due to Fukushima = .001 mSv/hr

    • "CRD Handbook on Rad Measurement and Protection..."

      Unfortunately, for all of us, that particular text was compiled and put into print on March 26, 1986, long after the US, the Soviet Union and other countries had already set off more then 2,000 nuclear explosions during testing. Is that taken into consideration when measuring radiation in a banana?

      Your banana is really more of a "relative reference banana", is it not?

    • by BillX ( 307153 )

      For that matter, I was shocked to discover that porcelain teeth emit a surprising* amount of radiation. For a 5th grade science fair project, I took a handful of dental X-ray films (my father is a dentist) and attached them to various everyday objects folks (or 5th grade kids) might be suspicious of emitting radiation, then developed them in batch after one month of exposure. For the youngsters who have never seen a dental x-ray using real film, they are small (about 4x5cm) squares of photographic film seal

  • Googled for "ratiation detectors for Japan []". Found this interesting link [], among other things.

    I was going to echo the general attitude that the fears are probably misguided, but somewhere in the Church literature (I'm "Mormon") I was reading several months back, I noted that we had sent a bunch of radiation detectors to the Touhoku area.

    So they apparently are either taking the risk seriously, or they are wanting to provide our members with a way to check and avoid unnecessary worries.

    But you might check with

  • So the story others have pointed towards talks about a "neutron hotspot" someone found. The measured level of neutron radiation is 464 nano-Sieverts/hour. That's an annual dose of 464*24*365= about 4 million nano-sieverts/year, or 4 milli-sieverts/year. Background radiation varies in the world from around 2-6 milli-sieverts/year. So essentially the additional neutron radiation is about equal to a normal background radiation. Basically these so called "hot-spots" are completely harmless. If you're espe

  • [] sells a Geiger counter kit. They specifically state that it's not for life-or-death situations, but it sounds to me like all you really need is a little peace of mind. For $99, plus shipping and a little elbow grease, this should do the trick.

    If, on the other hand, you have reasonable cause to think that there is a real threat in your area, then disregard my suggestion. I don't know enough about the subject to provide the answers you need.
  • by EmperorOfCanada ( 1332175 ) on Friday October 21, 2011 @09:05PM (#37800780)
    Here is a way to build your own radiation detector to check a sample. [] The coolant used is an air duster can turned upside down. Any self respecting slashdotter should have one of these.
    So basically what you need is isopropyl alcohol 99%, a clear sided container with the bottom painted black, a bright flashlight, a small rag or tissue, and an air duster can.
    Should be able to build it in 10 minutes. If you have a hot source you will see many streaks of radiation. With background radiation you will only get the occasional streak. Maybe one every 20 seconds.
  • You used to be able to get a Geiger counter on eBay for well under $100 (which is itself a rip-off because in Eastern Europe they are really cheap). After Fukushima people went crazy in countries as far away as America thanks to our media's 24-hour *F*E*A*R* cycle. Prices jumped up to $1000 and were sold out for many months in advance. They've fallen back to $400. Still a rip-off, but wait and they will keep falling.
  • They have Geiger Counters at most government facilities now and will come and check areas of concern. Out of curiosity I went to a nearby civic center and had my cars air filter checked out after I drove through Fukushima (on the Touhoku expressway) and it didn't read higher than normal. Then a week ago there were concerns over mushrooms from the area and my wife had some checked out. It's not just government facilities offering the service - depending on where you are community centers and other groups, su

  • There were 2 radionucleides released which are particularly important: iodine-131 and cesium-137. Of those, ioidine-131 is about 1000x more radioactive and has a half-life of about 8 days. It has already done its damage and decayed. Only 0.01% remains. In other words, the horse has already left the barn. If you wanted to do something, then the time to do so was within 2 weeks after the meltdown.

    Your chances of having been harmed are small.

    Don't take anything you read on slashot too seriously.

  • Greenpeace Japan just came out with a report on supermarkets a couple days ago and they are pro-consumer.
    They might have some info.
    Generally the radiation went over Tokyo and landed in Shizuoka destroying the green tea crop.
    There are a couple hotspots though the main one I think is some idiot who was storing bottles of radioactive water.
    I doubt your gutter is a problem but then again you could clean it out..
    The main issue for you is that for infants, extremely slight contamination of Tokyo water, shellfish

  • by B5_geek ( 638928 ) on Friday October 21, 2011 @10:50PM (#37801398)

    First and foremost, as others have posted this is too late to worry about it, AND there is nothing to really worry about.

    BUT, if you want to approach this as a fun sort of science-fair project that will only tell you 'IF' and not 'HOW MUCH', read on.

    You have 3 dirt-cheap and easy ways to detect radioactivity:

    1) take an unexposed roll of film (B&W might make it easier to see) and place it near to suspected source. Go develop the film. If you see alot of 'static' then there might be something there. (make sure the place that develops it does the whole roll and doesn't try to malipulate/enhance the image for you) Tell them you will pay for all frames including the 'blank' ones. *For bonus points, you make a frame that you can mount strips of unexposed film to and 'aim' the film at the suspect areas. (make sure you keep the film away from the light)

    2) (must be done at night) grab an old phosphor screen (like from an old television), as radiation hits it you will see small flashes of light like static

    3) Use a smoke detector. as beta particles pass through the detector, the alarm will go off

  • Some come with data ports and you can help map Japan at []
  • It's the only way to be sure.

    Then you don't have to worry. You'll know it's hot!
  • Detector in Tokyo (Score:5, Informative)

    by Bushcat ( 615449 ) on Saturday October 22, 2011 @12:34AM (#37801836)
    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.
  • by Renraku ( 518261 ) on Saturday October 22, 2011 @12:48AM (#37801880) Homepage

    There are three types of radiation you have to deal with when it comes to fallout. Alpha, beta, and gamma.

    Alpha radiation can't even go very far through the air. Few inches give or take. It isn't dangerous to you at all unless ingested.

    Beta radiation goes a little farther but isn't dangerous unless very concentrated and close, or is ingested.

    Gamma radiation is what you would have to worry about the most, but significant levels aren't going to accumulate near you unless you're directly in the path of the fallout. In which case there would likely be much higher radiation readings between you and the plant.

    As for alpha and beta, you won't be able to easily test for these. These are mostly rather transient in nature. Gamma rays you can easily test for, just buy a Geiger counter online and make sure it works. Your local university would probably be glad to help you calibrate it, talk to the physics or nuclear engineering department.

"The pyramid is opening!" "Which one?" "The one with the ever-widening hole in it!" -- The Firesign Theatre