Greenpeace conducted a survey for fish sold at 5 major supermarket chains.
They are AEON, Itoyokado, UNY, Daiei, Seiyu
You can find one or a few of them everywhere around in Tokyo.
They searched at the branches in Tokyo, Kanagawa, Saitama, Ibaraki, Fukushima, and Miyagi
They used NaI scintillation detector (LB 2045), collaborating with ACRO.
As the result, all of them sold contaminated fish. (34 out of 60 samples)
Though the highest amount was 88 Bq/kg from UNY, it measured only Cs-134, 137.
When it comes to seafood, the main risk is Strontium, which is water soluble and can easily absorbed to the bone to cause leukemia.
Now there is the truth that if they ban selling all the contaminated food, food prices will be as double as before.
We pay money and life to live today.
(Source)