Appendix 3 A Summary of the Findings over the 20 Year Period on the Japanese Fishermen Exposed to Fallout in1954 On March 1 in 1954, 23 Japanese fishermen aged from 18 to 39 were exposed to radioactive fallout produced by the thermo-nuclear test explosion which was performed by the U. S. Authorities at Bikini lagoon. They were crew of a tuna-fishing boat "The 5th Lucky Dragon". The location of the boat was 166°58' E. and 11°53'N.. At about 3.50 a.m. they saw a huge red light in the west and heard detonationlike sounds 7 - 8 minutes later while they were fishing for tuna. At about 7.00 a.m. white ashes began to fall on the boat which continued for about 4 1/2 hours. After 14 days navigation they returned to their harbor, Yaizu, on March 14, 1954. After landing, all the fishermen were found to have been injured by the radioactive materials. Seven of them were hospitalized to the Tokyo University Hospital and the other sixteen to the First National Hospital of Tokyo by March 28. They were discharged from both hospitals in May 1955, except one fatal case who died on September 23, 1954. After being discharged, most of them have been examined so far as possible on an anual basis. A. State of Irradiation and Estimated Radiation Dose When fallout fell most intensively they could not keep their mouths and eyes open. Fallout deposited on the deck as thick as their foot prints were marked. three ways : The persons were irradiated in the following 1) From the radioactive materials adhered to the skin 2) Externally from the radioactive materials in the cabins, on the deck etc. 3) Internally from the radioactive materials entered various organs. The estimation of radiation dose to skin as well as the dose by internal exposure were difficult. - On the other hand, the estimated 8689 -