B. Radioactivity In Food, Water Supplies and Air 1. Activity in Cistern Water The main water supplies at Rongelap, eight cisterns, each contained 0.23 m high of water during the later part of March and early April 1954 (Sh57). (He65). Held reported a storm with heavy rain on or about March 15, 1954 This storm followed many weeks of drought (Sh57). Water was drawn from six of these cisterns at Rongelap for gross beta analysis on March 2, 1954 (Report of the USS PHILIP, 0C68), and one other cistern was reported as out. Each cistern opening was about 0.65 me (see Fig. 8) and was fed by galvanized metal sheeting used for catching rainwater (Sh57). on the afternoon of March 1, 1954 (Sh57). A little rain was reported The additional area for catchment of water with subsequent runoff into cistern ‘water was not assumed to contribute to the estimate of water or activity in the cistern. The concentration of activity was taken to be dependent on cistern water height which was taken to be at the level reported by Sharp (Sh57). Fallout in runoff feeding the cisterns and a different cistern water height, both of which were possible on March 1, 1954 would impact on the estimate of water activity concentration. Results of the analysis for gross beta activity concentration in cistern water ranged from 11,000 to 120,000 dmm1! with a mean of 60,000 dm? m1? at 50 hours post detonation (0C68). The fallout from Castle series coral surface bursts including BRAVO was barely soluble in water (Ka66). Rain and water would have disolved part of the fallout particle and released only a fraction of the iodine near the surface of the particle (Ka66). In BRAVO fall- out which was collected with mixtures of rain and sea spray, 20-50% of the io~ dine activity was found in the liquid phase (Ka66). The servicemen at Rongerik Atoll examined the terrestrial fallout under a microscope and reported that the 23