Abstract
The eastern Japan where has been affected by the nuclear event formed in Fukushima 1st nuclear power plant after March 12th in 2011 was studied by a scientist in a wide range of 800km on nuclear hazards and affected population a month later of earthquake disaster and 3 months later. The annual external dose of the eastern Japan except for Fukushima prefecture is less than 1mSv in 2011. That one is evaluated to be generally less than 10 mSv for population in Fukushima considering the long period of the indoor sojourn time. Radioactivity of iodine 131 in thyroid of 76 people has been measured and then the dose was evaluated to be less than 8 mGy. Portable whole body counter on Fukushima 33 people was carried out and showed annual internal doses to be less than 0.1 mSv. These low doses indicate us no health effects in Fukushima incident.