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."
Safecast (Score:3, Informative)
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 . . .
Measurement (Score:5, Informative)
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)
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.
Re:Save your money. (Score:4, Informative)
Re:Gamma rays (Score:2, Informative)
It's not proximity to static sources that will hurt this man and his children. It's ingestion, inhalation etc. Think food chain, water and dust/air contamination.
Radiation levels in the bay off Fukushima are not falling. Consider what that means.
Re:Don't feed your child bananas! (Score:5, Informative)
(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
Re:I can't figure out Slashdot . . . (Score:2, Informative)
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 some definitive source for geiger counters -- especially since if you are in Japan, you'll probably want a local source rather than a US one, and there are few people on here that'd know where to buy anything in Japan. if you want to buy a geiger counter, buy one, but it'll be expensive. Alpha and beta particles are harder to detect, that is because they do not even penetrate the top level of the skin (so any contained detector, the alphas and betas will probably bounce off the case.)
Thirdly, this recent radiation scare proved to be because of vials of radium on-site, and was not hot enough to be harmful anyway.
3 different cheap DIY 'detectors' (Score:4, Informative)
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
Re:I can't figure out Slashdot . . . (Score:4, Informative)
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:
Detector in Tokyo (Score:5, Informative)
Re:Save your money. (Score:5, Informative)
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:
http://www.mext.go.jp/english/ [mext.go.jp]
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.