Wednesday, March 16, 2011

Live Geiger counter in Tokyo

Here's a web-enabled, real-time radiation sensor in Tokyo:

The graph is showing Geiger counts per minute. Around 100CPM = 1 microsievert/hr, the common measurement you're hearing in the news around the Fukushima Daiichi plant accident. Around 1 millisievert (1,000 microsieverts) per year is normal radiation exposure. (Tokyo's normal range of 15-20CPM, equivalent to .15-.20 microsieverts per hour, works out to around 1.5 millisieverts per year, which is pretty common for a congested urban area.) 100 millisieverts (100,000 microsieverts) in a short period of time can cause a severe risk of injury or cancer, but levels below that can also cause increased risks over time.

As you can see, at the moment the radiation level is pretty normal (this is equal to the reference graph below it on the site). But there have been times over the past few days when it has spiked a bit, though nowhere near a dangerous level. I personally probably wouldn't really start to worry until I saw this meter inching up past 5,000CPM. Even that is still low level radiation, but if it goes that high so far from the plant, it's definitely worth watching, at least. That would still be just 50 microsieverts/hr. For reference, a typical CT scan is about 15 millisieverts (15,000 microsieverts), but it's worth remembering in any example like that that you don't typically have a CT scan for more than a few minutes at a time, and doctors won't let you have more than a couple per year. So whenever you see people cite such examples, they're not really examples of radiation you can live with on a continuous basis - but they are examples of what the human body can absorb in a short period of time without any ill effects.

If you're in Tokyo or know anyone who is, it may be worth checking the site linked above every once in a while until the situation in Fukushima is resolved, especially given the useless government and TEPCO announcements that aren't telling anyone what's actually going on there.

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About This Blog

This is increasingly not a blog about Alphabet City, New York. I used to live in the East Village and work on Avenue B, but I no longer do. Why don't I change the name if I'm writing about Japan and video games and guitars? Because New Yorkers are well-rounded people with varied interests, and mine have gone increasingly off the rails over the years. And I don't feel like changing the name. I do still write about New York City sometimes.


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