[ RadSafe ] Cesium in Fukushima fish
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:
> 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:
> 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
> 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:
> 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.
> Best wishes for the weekend,
> Mattias Lantz
More information about the RadSafe