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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."
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)
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.