Mad River Tap Room, Blue Lake, CA – Dec 5, 2012
- I added another radiation data source to my list of Radiation Monitors in Japan:
h/t: Fukushima Diary‘s Dec. 1, 2012 reporting: ‘Radiation level spiked up in west coast of Japan for about 10 hours‘, which includes the above source.
It’s a large collection of monitors across Japan, graphing radiation measurement (in the SI radiation dose unit µSv/h (‘microSievert per hour’ – see Radiation Units for conversion info) in near-real-time: http://ma-04x.net/all.html
This image (below) is a screenshot I took today (Dec 5, 2012 in California, already Dec 6, 2012 in Japan), showing clearly that radioactive particles continue to be blown around and/or released into the atmosphere:
The radiation swings are too much to be attributable to anything natural (for sea level, at least), so it must be ongoing Fukushima radioactive dust blowing around. An example of one monitor, below. (I don’t read Japanese (yet) and the images make copy-pasting for translation not possible, so I don’t know the precise location for this monitor.):
Couple notes that may help interpret the data (couple more data snapshots further below):
- Beware of the inherent “deceptiveness” of radiation ‘dose’ comparisons. As I pointed out on my ‘Radiation Exposure Effects (Health Effects)’ page awhile ago, comparing the dose of an air plane flight, for instance, to the calculated “dose” received from ingested or inhaled fallout particle (Cs-137, I-131, etc.) is completely ridiculous. A blip of 0.5 µSv/h of cosmic rays is nothing unusual at higher altitudes, where background radiation often spikes over 0.3 µSv/h (which I also measured myself when I lived in Park City, Utah at 8000 ft., in June 2011). Another example: On a transatlantic flight (Belgium to USA in June 2011, using a Gamma Scout), I measured over 6.o µSv/h: completely normal natural background radiation at 35,000+ ft altitude. The transmitting source of this radiation is external (exploding stars very far away, etc.) and does not get absorbed.
On the other hand, you can have an area with a “2.91 µSv/hr” dose rate, which doesn’t seem like much, but it is INCOMPARABLE to that same ‘dose’ from an X-ray, CAT-scan, or what not, when much of that “dose” comes from radioactive particles that are ingested/inhaled/absorbed. 2.91 µSv/hr was the reported background radiation, a meter above the ground level in parts of the Fukushima Prefecture in April 2011 (see my (unanswered) June 6, 2011 blogpost ‘Background Radiation DOSE & fallout deposits’ ACTIVITY… – What’s the calculation trick?‘), which showed a fallout deposit of about 3,7oo,ooo Bq/m^2 (3.7 megabecquerels per square meter) in the very same area. By the way, if you’re not sure if 3.7 Mbq/m^2 is bad, it’s “off the scale” used for Chernobyl, where areas over less than half that (1.48 MBq/m^2) faced mandatory evacuations (see also my Fukushima 2011 versus Chernobyl 1986 fallout map comparison). Anyhow, make no mistake about it: a spike of even just 0.05 µSv/h at sea level, from fallout, implies a much more significant health risk than its ‘dose’ seems to hint of. [DISCLAIMER].
- Just for reference, radiation in the Fukushima Perfecture is currentlty described as ‘normal’ (wtf) by the Japanese Government:
- Part of this Japanese new “normal” apparently includes the whopping 18080 nGy/h (nanoGray per hour, which is a human-specific dose, which tranlates to 1.808 µSv/h in the air immediately above the monitor’s location in the insanely contaminated Yamada Futaba Town (in the exclusion zone, less than 10 miles North of the ruined and still-leaking Fukushima-Daiichi Nuclear Disaster Plants (for which ‘J-Village‘ is a good point for Google-mapping).
- Other towns in the Fukushima Prefecture currently show these (below) measurements (Dec 6, 2012 in Japan, still Dec 5 (almost 8pm) in California):
SCREENSHOT FOR REFERENCE: