APPENDIX V. AIR SAiiPLING PROGRAM Air samplers were operated on eight populated islands during operation HARDTACK, These included the six major Sampling stations on Wotho, Utirik, Ujelang, RNongelap, Parry, and Eniwetok plus the island of Japtan just north of Parry and Kwajalein, Samples were taken daily during the first part of the operation, but due to equipment failures this was abandoned and samples were taken for a period of 48 hours after each shot, The samples were taken with a Standard Staplex air Sampler employing a four inch head, For processing, the samples were sent to the AEC field office in Las Vegas, Yeveda. A gross beta count was tkken and this compared to a Sr-¥’~standard source to obtain the concentrations in air a certain number of days after coljection, attached, These data have been tabulated and are Since the samples were only counted once, no attempt has been made to assign an age to them, However, activity values determined at the count time were extrapolated to the end of the collection, The assumptions made in the extrapolations were that the activity decay rate followed the tl. law; that the activity of each air sample was entirely due to the preceding detonation; that residual activity from detonations other than the preceding one was regarded as having been formed by the preceding one, Extrapolated values for samples collected on a shot day were determined at the (H+1l day) level as it was not practical to extrapdlate beyond this point, All other samples were extrapolated at the actual time interval from the preceding shot to the end of collection time, Example of extrapolation method: Conditions: At the first count, the activity of the- Sample was equal to 30 mmc /al?, The time elapsed from the end of the collication to the first count was 23 days. collected 2 days after a detonation, Solution: The sample was Days from shot day to first count equal 25. Using the "Radiation Dosage Calculator,” set 25 days opposite 30 on the outer dial. Read activity at end, of collection on outer dial opposite 2 days which equals 625 mme fil, About 85 air samples were followed for decay and absorp- tion over a two months period, However, the raw data has not yet been analyzed and no significant conclusions can be drawn at this time, at