Farmers in contaminated areas in Fukushima, Miyagi, Iwate, Tochigi, Ibaraki, Gunma, and Chiba continue to farm, and the government is busy setting up one PR campaign after another to appeal safety of things produced in Japan. The media do report, but unless your information comes from the net only, the news gets buried in the cacophony of mind-numbing small news of no significance on TV and print media.
Here's the list of food items that I found which exceeded the new safety limit of 100 becquerels/kg of radioactive cesium:
Shiitake mushrooms: 350 becquerels/kg from Murata-cho, Miyagi Prefecture
Bamboo shoots: 120 becquerels/kg from Kisarazu City, Chiba Prefecture; 110 becquerels/kg from Ichihara City, Chiba Prefecture
Bamboo shoots: 130 becquerels/kg from Sakae-cho, Chiba Prefecture; 170 becquerels/kg from Abiko City, Chiba Prefecture
"Komon Kasube" (common skete): 640 becquerels/kg, test fishing off the coast of Iwaki City, Fukushima
Beef: 106 becquerels/kg from Shibukawa City, Gunma Prefecture (the cattle had to eat the feed (rye) with 772 becquerels/kg of cesium...)
"Suzuki" (sea bass): 104 becquerels/kg in Sendai Bay, Miyagi Prefecture
Shiitake mushrooms: 146 becquerels/kg from Shirosato-machi, Ibaraki Prefecture; 131 becquerels/kg from Sakuragawa City, Ibaraki Prefecture
"Wakasagi" (pond smelt): 426 becquerels/kg from Akagi Onuma in Gunma Prefecture
1, 2, 4: Nikkei Shinbun (4/4/2012)
3: Chiba Prefecture press release (4/5/2012)
5: Yomiuri Shinbun (4/5/2012), Gunma Prefecture press release (4/5/2012) for meat, and for feed
6: Miyagi Prefecture press release (4/4/2012)
7: Ibaraki Prefecture press release (4/2/2012)
8: Kyodo News (4/3/2012)
All these food items (except for No. 4) would have been freely sold and bought, as "safe", under the old, provisional safety limit that was in effect up till April 1, 2012. Checking the prefectures' press releases, there are many other whose cesium levels are barely under 100 becquerels/kg.
In case of Gunma Prefecture, they use NaI scintillation survey meter with detection limit of about 30 becquerels/kg. Only when the meat is found with cesium exceeding the rather high detection limit, they use their germanium semiconductor detector.
This happened last month in March, but a kindergarten in Okazaki City in Aichi Prefecture (whose governor is pushing Toyota to become the final disposal site for disaster debris ashes) served lunch to kindergarteners using dried shiitake with 1,400 becquerels/kg of radioactive cesium from Ibaraki Prefecture. 30 kilograms of these shiitake are either in the markets or have already been purchased by customers in Okazaki City. (NHK News, 4/5/2012)