Environmental radiation status in and around Tokyo immediately after the TEPCO Fukushima Dai-ichi nuclear power plant disaster

Abstract

An example of environmental radiation status in and around Tokyo immediately after the TEPCO Fukushima Dai-ichi Nuclear Power Plant (NPP) disaster is introduced. The east part of the Metropolis of Tokyo and northwest of Chiba Prefecture are located about 200–250 km south from the NPP. The local governments in the area have offi cially surveyed the environmental radiation status after the disaster in response to numerous requests from their citizens. The radiation surveillance by local governments has been conducted and technically guided by the radiation protection specialists. The two main goals of the surveillance are (1) to measure the ambient radiation dose (microsieverts per hour) at all the schoolyards, public parks, and representative measuring points selected by the local government, and (2) to measure the specifi c radioactivity (becquerels per kilogram) of drinking.