Ae ee RADIOACTIVITY BACNGROUND IN THE OrsN SEA 455 LAGOONS OF THE PACIFIC PHovVING GROUNDS AnEG 2 by DeCourcey Martin, Jr. and Nooert L. Wisner = The M, V. HORIZON 4s equipped with a smell radlochemical 3 iaboratory, radiation setection and assay equipment, and ampling devices. Assay of the radioactive contavination in the Paecifie Froving Ground Area was dome in cenjgunetien with the prelininary cceancgterhnic studics. A study was meade of the redioaetivity of the waters in ad the ° oper ocean. Samples of the Isgoonge and ccoan Ploor were ah . n oS << obtained with a coring davice and wy Gyedge, aoa jn: oo ant oes Piankte. samples » were taken dn the oven ocean and phytopicrkton aad solloided nathe were filterec Crom lagoon waters. isms ' ( ee . Gther ravine orgtae were osteined by trawling, Line fishing and szin-diving. Several semples were teken of the air over the see surface. 2.1 ASSAY EQUIPHEIN: my fey cre oe yt tt mat pee aos samples were meesvuved Por uf ~~, ation. Those samples . os os anglyzai 3 oe 7 my ine a } Séwy to determine i eS raed =] WwW cS ann a eytoe, sry 4 ‘woth beta end ganne vedi- aa Le Dba nant} mene waish vere sulfieiesnily ageire le . by weans of7. gamma ray. mom ent hated the isctopes Jeg et eRe produsing wn oD ah Aned, si e654 AQCAVLLLGa $ fe rf EM: An end-window Geiger-ltiller tube, wlth met fet o pt the traviction oe Kos ow. sa ay Giffercnviah pulse heignt I. = vare snalysis. veeremoanta|d YI Sras SQ Fe OT a mica win The counting tube was shielded by tuo inches of lead to reduce the background of cosmic and externel instrument a li ep 13 /3