Abstract
The authors report results on space does of radio activity after the great East Japan earthquake. In this paper, three results of radioactivity measurements are reported. The first result is the space dose of radioactivity at Gunma National College of Technology with a scintillation survey meter. While the space does in a room has been almost constant, the one in the outdoor decreses gradually. This suggests that radioactivity substances caused by Fukushima Daiichi nuclear disaster decreases. When the authors went to Ishinomaki city for volunteering, the space doses were measured. Moreover, students measured the space dose with a personal doesmeter.
