- This data was created based on the results of "Reinforcement of Environmental Radiation Monitoring in Examination Operation Sea Area" released to the public in the Fukushima Prefecture Government website.
- Corresponding to the revelation of highly contaminated water leakage to the exclusive port of Fukushima Daiichi NPP on July 22, 2013, the "Environmental Radioactivity Monitoring by Fukushima Prefecture (Ports and Sea Surface Fishing Ground) " has been conducted. This survey picked 6 sampling points within the examination operation sea area from the sampling points of the monitoring mentioned above. In addition to the nuclides analyzed in the said monitoring, tritium and all beta radiation were also analyzed. The seawater samples were collected at the outer layer and at the sea depth of 7 m.
- This survey has been conducted every month since August 2013.