I used to think canned food was ok, but even that was an illusion.
Greenpeace measured canned fish.
The samples were taken from 15 branches of 5 major super market chains from North Japan to Kanto area. The measurement was conducted in October.
As a result, they measured cesium from 27 of 75 canned fish.
They announced it on 11/16/2011.
Eg,4.6 Bq/Kg from canned chub mackerel.
This seems to be merely a beginning of the huge food problem. Greenpeace is expected to conduct continuous surveys.
(Source)
Greenpeace has also measured variety of sea food sold at major supermarkets.
The data is below.
20111117 SUSEA Result