I have just read the news in the New York Times : Radiation-Tainted Beef Spreads Through Japan’s Markets

Quote Originally Posted by New York Times
Japanese agricultural officials say meat from more than 500 cattle that were likely to have been contaminated with radioactive cesium has made its way to supermarkets and restaurants across Japan in recent weeks. Officials say the cattle ate hay that had been stored outside and exposed to radiation.
Radioactive material has been detected in a range of produce, including spinach, tea leaves, milk and fish. Contaminated hay has been found at farms more than 85 miles from the crippled Fukushima Daiichi plant, suggesting that the radioactive fallout has reached a wider area than first suspected.
The government has suspended agricultural shipments from within a radius of about 12 miles around the Fukushima plant, as well as a number of other identified radiation “hot spots.” But farms outside those areas, even those relatively close to the plant, have faced few restrictions in shipping their produce.

For months the government balked at placing a wider ban on produce from the Fukushima region despite sporadic discoveries of contaminated produce, for fear of bringing fresh confusion in the disaster-stricken area, putting thousands more people out of work and adding to growing compensation claims for Tokyo Electric Power, which operates the Fukushima plant.
I stopped eating beef for years after the BSE cases in Europe and Japan. I surely won't go back to Japan without a Geiger counter to make sure my food is not (too) radioactive. I even thought of buying one for imported Japanese food products (like soy sauce and green tea).