Blog shows I-131 in 1/20/12 Tokyo snowfall
I am not sure what to make of this. It is a on a blog but the equipment is not junk - http://fukushima-diary.com/2012/01/iodine-131-measured-from-snow-in-hach...
If there were just the cesiums present I would chalk this up to wind-borne dusts being "snowed-out", but the I-131 is a whole different cup of tea. It cannot be from the original accidents. I checked the decay energy of another common nuclide found in rain and snow (Be-7) and they are far apart from each other so it's not that.
Mi no sabe.
BC 1/20/12
I-131 found in Minamisoma tap water 3-2-12 = criticality
Title: Iodine131 measured from tap water in Minamisoma
Source: Fukushima Diary
Date: March 5, 2012
Citizen’s volunteer group HCR reported Iodine 131 was measured from tap water in Minamisoma. [...]
Location : Daimachi Minamisoma
Date of the analysis : 3/2/2012 [...]
Iodine 131 : 5.37 +- 2.60 Bq/kg (Detectable amount : 4.01 Bq/kg)
Cesium 134 : ND (Detectable amount : 11.0 Bq/kg)
Cesium 137 : ND (Detectable amount : 11.7 Bq/kg)
See lab report at:
http://fukushima-diary.com/2012/03/iodine131-measured-from-tap-water-in-...
Clarification
Via the safecast mailing list -
"Thanks for the clarifications:
The Pb-214 half-life seems to match with the half life I observed when measuring a fresh snow sample. Though I didn't have the SAM handy, I used absorption filters which indicated it was a beta emitter.
It is good to understand this phenomena here in Japan, as people will measure it and confuse it easily for Fukushima related contamination."
Appears that this was not I-131 but Pb-214 radon daughter....
BC 1/26/12
Further info.
I hope I don't look like a ding-dong being the only one to post one a thread I started, but I thought this info was pretty interesting and important and I do like to follow a story to completion.
http://blog.safecast.org/
In a nutshell the recently detected radioactivity in snowfall rapidly decayed to background, indicative not of fallout by radon and friends.
BC 2/4/12
Informative
Hi, BC.
Thanks for this thread. It became a bit chaotic there when this happened. I am Japanese, so I gather a lot of information available in Japanese. I am glad you are keeping an eye out. There was a significant earthquake there on January 1, and the measurements in some places went up quite a bit several days afterwards. Do you think the fallout came to the west coast from that event?
Are you familiar with the civilian soil testing project?
http://www.radiationdefense.jp/?lang=en
You're welcome
I am aware of the 1/1 earthquake, but I have no indication that any fallout was generated by that event either here or in Japan.
The link you sent is quite interesting, I had not heard of them but am familiar with safecast who is doing some good work in your country. They have a google group that you can subscribe to which may provide you with some info.
http://groups.google.com/group/safecast-japan/about
If I was in Japan I would be on this mailing list for sure.
BC 2/10/12