[ RadSafe ] Cesium in Fukushima fish

Maury maurysis at peoplepc.com
Fri Oct 26 14:26:12 CDT 2012

Thank you very much for the information you have added to this picture.
Hope yuo have  a pleasant Fall weekend,
Maury&Dog          [MaurySiskel  maurysis at peoplepc.com]
On 10/26/2012 12:03 PM, Lantzelot wrote:
> Maury,
> The measured activities in the Baltic Sea may be an interesting 
> comparison for "extreme" values.
> Anti-nuclear groups often mention the Baltic Sea being the world's 
> most radioactive sea, see for instance the following document with 
> Cs-137 levels in fish from various seas measured during the 1990's: 
> http://www.nonuclear.se/files/baltic-radioactive200612.pdf
> As you can see from the first graph the activity is of the order of 20 
> Bq/kg fish, though near some sediment hot-spots fish with up to 200 
> Bq/kg have been found (there are inland fish in Sweden with much 
> higher levels). The activity level of Cs-137 in the water is about 45 
> Bq/m3.
> As a side note, the relatively high level is due to 80% from the 
> Chernobyl accident. The rest is from atmospherical nuclear tests in 
> the 1950-60's and from the Sellafield and La Hague processing plants. 
> Only 0.04% is from the nuclear facilities around the Baltic Sea 
> (something that is rarely mentioned by the anti-nuclear groups, it 
> somehow ruins their argument).
> The activity decreases slowly due to dilution from the rivers that 
> enter the Baltic Sea, but in comparison with other waters in the world 
> this is a rather slow process due to the closed system with only a 
> narrow exit between Sweden and Denmark (see this map that indicates 
> all areas where water systems go into the Baltic Sea: 
> http://www.grida.no/baltic/related/balans_lc.jpg).
> Less than 2.5 Bq/kg is considered to be a "normal" level, and the goal 
> is to reach that level within a foreseable future.
> Therefore the levels near Fukushima, in an open sea basin of very 
> large volume (the Pacific Ocean), is of concern. Please note that the 
> article mentions that it is for bottom-dwelling fish. There may be 
> hot-spots in the bottom sediments (there are some in the Baltic Sea 
> with rather high levels, several 100 kBq/m2) that locally will supply 
> fish with high levels for a very long time. So it will have to be 
> investigated closely and monitored for a long time. Ironically, a ban 
> on fishing in the area may have some positive effects on the local 
> marine life, no risk for over-fishing.
> Anybody interested in more details about the radioactivity levels in 
> the Baltic Sea is recommended to read the Baltic Sea Environment 
> Proceedings No. 117 published by HELCOM  (Helsinki Commission - Baltic 
> Marine Environment Protection Commission) in 2009.
> http://www.helcom.fi/stc/files/Publications/Proceedings/bsep117.pdf
> Best wishes for the weekend,
> Mattias Lantz

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