radiological safety monitor equipped with suitable RADIAC equipment and a radex plot. This monitor shall be capable of calculating allowable exposures under both tactical and Operational conditions. (4) All persons in aircraft at shot time, or at subsequent times when engaged in operations in or near the cloud or radex track, shall wear film badges. (5) Pilots and copilots of aircraft in the air at shot time shall use modified all-purpose 0.1 density filter goggles. Copilots should, as an extra precaution, cover their eyes with forearm at zero hour. e. In air and water the following continuous levels of radioactivity are considered safe from the viewpoint of personnel drinking and breathing: (uc -— microcurie). Long-lived Alpha Emitters Beta or Gamma Emitter NOTE: Water Air 5 x 1073 uc/cc 1076 uc/ec (at H+3 days) 1077 uc/ec 6 x 10742 uc/ce In air for any 24 hour period after a shot, 1074 uc/ce of which particles less than 5 microns shall not exceed 1076 uc/cc). 13. All radiological safety operations for Operation CASTLE will be con- sidered as routine and will comply with permissible radiological exposures for routine work, except “special operations" which must be specifically designated by CUJTF SEVEN. In tactical situations the military commander must make the decision regarding allowable exposures. As military personnel are normally subject to only random exposure, health hazards are at a minimum. Current Department of Defense information on exposure to gamma radiation in tactical situations is indicated below: a. Uniform acute (immediate) exposure of 50 roentgens to a group of Armed Forces personnel will not appreciably affect their efficiency as a fighting unit. b. Uniform acute exposure of 100 roentgens will produce in occasional individuals nausea and vomiting, but not to an extent that will render Armed Forces personnel ineffective as fighting units. Personnel receiving an acute radiation exposure of 100 or more roentgens should be given a period of rest and individual evaluation as soon as possible. c. Uniform acute exposure of approximately 150 roentgens or greater can be expected to render Armed Forces personnel ineffective as troops within a few hours through a substantial incidence of nausea, vomiting, weakness and prostration. Mortality produced by an acute exposure of 150 roengtens will be very low and eventual recovery of physical fitnesS may be expected. d. Field commanders should, therefore, assume that if substantial numbers of the men receive acute radiation exposures substantially above 444