We conducted a radiation hygiene survey after the March 2011 Fukushima Dai-Ichi nuclear power station disaster due to the tsunami caused by the enormous earthquake. Our survey has revealed that the public annual dose was 10 mSv following the disaster and in situ dose evaluations did not suitably address health hazards. This study has focused on internal dosimetries of iodine-131 in the thyroid and cesium-134,-137 in the whole body. We have especially been studying radiation hygiene in cattle livestock in Namie, a town located within the 20km evacuation zone around the Fukushima Daiichi nuclear power station. To date, we have found no problem regarding recovery prospects.