Radionuclide concentrations in the drinking water of Bikini cisterns, pci/liter in June 1975. Table 1. Building that the cistern collects from 1376. 90... 239,240), 24 2.5 1.8 L.l 1.9 7.9 x 107? 13.7 x 107° School 1.7 1.4 29.0 x 107° 5 drained from the windward roof of each building. Ground water has also contained 0.6 + 0.2 fCi/liter of 239,240... and 0.09 + 0.04 pCi/liter been used for drinking in periods of of 13766. drought and will be used in the rain-water supply collected at future whenever cistern water is Kwajalein Atoll and is therefore unavailable. indicative of fallout concentrations The ground water is This water came from the presently in high demand for agricul- in Marshall Island rainfall. The ture on Bikini Island. 239,240), and 13766 concentrations Three of the cisterns were first in Marshall Island rainfall are then sampled in June 1975 and analyzed for approximately 1/20 of the concentra- Iles, 29g, and plutonium radio- tions in the Bikini cisterns. nuclides. therefore conclude that the Bikini The results are abstracted in Table 1? From an examination of We cistern water contains levels of the fallout in rainfall at other plutonium radionuclides that, while Pacific islands over the period 1968 small, are nevertheless significantly to 1974, it was concluded that the 906, and, by analogy, Seg and elevated above the levels expected from worldwide fallout., The higher 239,240), concentrations in the concentrations could originate from cistern water did not result solely leaching of the concrete cisterns from worldwide Fallout.” Instead, the (the concrete used for the cistern cisterns appear to have contained construction was locally derived) or, locally derived levels of radio- alternatively, from labeled particles nuclides. being resuspended in air, accumu~ In support of this conten- tion, two water samples collected by lating on the drainage surface of the one of the authors (V.N.) in October roofs, 1975 from the drinking water tanks cisterns with the next rain. on the ERDA-supported Marshall Island latter mechanism is correct, research vessel, the R. V. Liktanur, suspension processes contribute Wea 5010221 then being washed into the If the re-