-410- Several of these reports will be completed this year; the remainder (and some not listed above) will be nearly finished in FY 1979. During November 1977, we resampled ground and cistern water at Bikini to evaluate the environmental residence times of several radionuclides. The main supplies of cistern drinking water were contaminated with coliform bactecia. This was reported hastily to DBER and Trust Territory officials, who will have health officers investigate the source of contamination. Air samplers were established and operated on the ocean reef at Bikini and Eneu Islands. This effort was motivated by our inability to explain reasonably the higher-than-fal lout plutonium concentrations in Bikini cistern waters and on the catchment roofs supplying the cisterns. We must determine if the higher concentrations result from airborne plutonium particulates injected into the atmosphere as marine aerosol aggregates by wind and wave action on the ocean reef. Water and suspended material were also collected from the reef near the air samplers for comparative anlaysis. The samples are still being analyzed. : Our planned trip to Enewetak In January 1978 was cancelled because storm damage now limits site operations; the trip is rescheduled for March 1978. EXPECTED RESULTS IN FY 1979 AND FY 1980: The WHO! joint cruise to the equatorial Pacific currently is . scheduled for 18 June to 13 July 1978. Sampling locations are established and are concentrated along the trajectories of the major fallout clouds so we can study the history of down-wind, down-current distributions of the close-in fallout. A major water sampling program is planned and more samples than one laboratory can handle adequately will be collected for analysis. Water from closely spaced depths off the bottom will be analyzed to determine if remobilization from bottom sediments is occurring. These results should benefit evaluations of any disposal procedures for radioactive wastes into the deep ocean. A number of sediment cores will provide data on redistribution processes of surface-deposited, close-in fallout debris. Manganese nodules, plentiful in certain regions that received high levels of close-in fallout, will be collected for anlaysis to determine if fallout radionuclides were Incorporated in the nodules. This study should provide significant information about the growth rates and processes of these deep sea nodules. . Our recent data from fish show a large discrepancy with the result reported on plutonium in fish during the 1972-1973 survey. We believe a large part of the discrepancy was in the analyses because water and other samples analyzed since 1973 show little temporal variations. Our plutonium concentrations in fish are significantly lower than the reported 1973 levels and are being used to update dose estimates to populations using the marine food pathway. However, to ensure that our results are representative of concentrations and doses that can be nee 17-18,