A. SUMMARY OF EVENTS Prior to Departure of Joint Task Force SEVEN Medical Team and Fnroute to Rabaul To our personal knowledge, the first indication regarding the incident of the TAKUYO MARU and SATUMA MARU (also spelled SATSUMA (old spelling)) was a message seen by Colonel Ralph M. Lechausse, USAF (MC), Staff Surgeon, JIF-7, on 19 July 1958. This was message date-time group 190204Z, routine precedence, from CINCPAC with information to Commander JIF-7, Eniwetok (see Tab A, Appendix I). This message originated in Tokyo at 10 a.m. on 17 July from MacArthur to State 110 and said, "CNO not adee pass by CNO 171905Z 2 Maritime Safety Board ships now engaged in Pacific survey projects in connection IGY have reported high levels of radioactivity in vicinity of Truk. Ships have informed MSB of 19,000 count per minute on scintillation counter, rain radioactivity of up to 100,000 coumts per liter and sea water radioac~ tivity of 247 counts per liter per minute. Vernacular press have given fairly extensive back page play to these reports. MSB officials told Naval Attache that crews on both ships are very worried about radio- activity. MSB, though not too concerned about reported levels of radioactivity, has diverted both ships to Rabaul for fresh water decontamination." In view of the absence in this advisory of certain important technical information (19,000 counts per minute, etc., of what? Effi- ciency of the counter, calibration, etc.), certain assumptions were tiePAIR? ~~ DOE ARc::-----5 Le Dee UTE ae8) cont 554wes nee. _