526962 -~ Extract: . Health Hasards of Operation Castle, fT, L, Shipman, u. D., Health Division, LASL, 6 Mares 1953 This ie in somewhat belated reply to your seam of 13 February 1953. have purposely been slow in answering in order that I aight have full opportunity to discuss the astter thoroughly with those people whos I consider the best authorities on these probleas. '‘y comments will be gmeral rether than specific and will pertups cover a good deal sore Cf territory tran was actually required by your request. ae far as actual health hasards at Operetio: Castle are coneerned, there is net auch one can say except that they will be sisilar to those at previous Eni+setok operatione only more so. The possibilities and the dangere of fall-out should be no greater thea has been the case in the pest. With cetonations of high yieid it becomes extremely difficalt te predict the a..oe and location of the fall-out pattern. Seas material otvicusily is coming down somewhere, and thors can never be any positive aseurance that some of this will not land on inhabited ielande or on ships of the Task Foree. If this does happen, it creates an annoying situatian, but in all probability not one which can in any way be regarded as truly hazardous. It mist be admitted that sose uncertaintics regarding thie astter etill exist, and if all conditions were just right, it aight be poeaible to preduse a situation aore than annoying, at least in the immediate vicinity of the shot islands. Ome situation which will be somewhat different from previous tests involves the necesaity of having ships of the Task Force enter contani~nated waters. It ia difficult to assess the amount of trouble this aight cause, bub examination of the pertinent data from Operatian Croesreads indicates that the contamination which will be acquired by snips operating in sueh waters ony be a nuisance but will not approach haserdoas conditions. Inel 2 of Inel 2 to TAB "F" . e /o