More than 50% over the limit, those mushrooms.
http://english.kyodonews.jp/news/2011/04/82903.html
TOKYO, April 3, Kyodo The health ministry said Sunday it has detected radioactive substances higher than the legal limits in mushrooms sampled Friday in Iwaki, Fukushima Prefecture, where the crippled Fukushima Daiichi nuclear power plant is located. The Ministry of Health, Labor and Welfare said it found the mushrooms to contain 3,100 becquerels of radioactive iodine and 890 becquerels of radioactive cesium against the limits of 2,000 becquerels and 500 becquerels. The announcement led the prefectural government to ask farmers to voluntarily refrain from shipping mushrooms in Iwaki.
Meanwhile, the science ministry said its helicopter, which examined air samples at the altitude of 160-650 meters, detected radiation of 0.30 microsieverts per hour in the sky above Kawamata in the prefecture -- a level more than 10 times the normal figures for the prefecture's sky at 0.01-0.03 microsieverts.