1. 1) Free blank map downloaded from http://www.freemap.jp/ on 30 October (2011).
2. 2) The Japan Ministry of Education, Culture, Sports, Science and Technology: Reading of environmental radioactivity level by prefecture[Fallout], The file was downloaded from http://eq.wide.ad.jp/files/110729summaryfallout_1400.pdf on 30 December (2011) (in Japanese).
3. 3) Sago, T.: Simple monitoring of low level contamination with γ-(X-) ray emitting radioisotopes using an evaporation procedure—With special reference to radioactive iodine—. Radioisotopes, 30, 602-605 (1981) (in Japanese).
4. 4) Yoshinaga, T., Shirakata, T., Dohtsu, H., Hiratsuka, H., Hasegawa, M., Kobayashi, M., Hoshi, T.: Polyvinyl alcohol as a useful indicator on iodometry: Volumetric and spectrophotometric studies on iodine-PVA and iodine-starch complexes, Anal. Sci., 17, 333-337 (2001).
5. 5) Japan Meteorological Agency: “Previous Weather Data” downloaded from http://www.data.jma.go.jp/obd/stats/ (in Japanese).