operations to assist aircraft in finding the best sampling areas. Pref aration of the air radex area consisted of selecting an altitude at th bottom of the volume under consideration, considering this altitude as surface plane, and constructing a hodograph using appropriate winds abdve the surface. Areas of possible contamination were then predicted by t use of diffusion factors applied to the resultant winds obtained, and ified to account for deviation from a point-source origin of fallout ( erence 16, pp. 66 and 67). Offsite Monitoring Much of the CUTF 7 planning correspondence (Reference 16, Tab C) clearly shows concern for the safety of the native population on the v ious atolls in the PPG. An 1l December 1953 communication to CINCPAC stated, "The decision to shoot should be reached with the understanding that no health hazard to .. . populated islands . . . will ensue." 4H ever, CUJTF 7 did not believe it necessary to monitor the islands for ra joactivity, or to sample the drinking water of distant atolls -~ a proced followed during Operation IVY in 1952. re CINCPAC did not completely conc A 31 October 1953 letter directed CJTF 7 to sample drinking water in th event "that radiological conditions require." A later letter (11 Febru ry 1954) directed CJTF 7 to assist the AEC New York Operations Office, Hea Lth and Safety Laboratory (NYKOPO, HASL) in aerial monitoring of inhabited atolls in the Marshall, Mariana, and Western Caroline islands. The sur reys were to be made only of those atolls where the possibility of contamina tion existed, rather than of all atolls as was done during Operation IVY. The aerial monitoring was conducted by aircraft operating from Kwaj lein and Guam (VP-29) and from Oahu (VW-1). The radiation detection eq ip- ment was provided by the AEC, but AEC staff members did not participate in the monitoring flights. Table 9 lists the potential flights and the is; lands each flight was expected to monitor. Ground monitoring stations were established by HASL at Truk, Yap, Ponape, Kusaie, Majuro, Rongerik, Ujelang, Wake, and Midway. recorders continuously monitored gamma radiation; however, Automatic the upper limit 116 oy