Contamination from Local Fallout In order to ascertain the degree of radiation hazard associated with residual contamination, survevs of the fallout contaminated areas have been conducted over a 5-vear period. The most comprehensive studies were made at ] and 2 vears following the accident ‘Rinchart et al. 1955: Weiss et al. 1956). Data were obtained on the residual activity in soil and on the uptake and retention of fallout material by plants and land and marine animals. Thesc data form the basis for an estimate of the radiation hazard associated with both an acute and chronic exposure to local fallout. It is perhaps the only long-term study of a community exposed to a significant local fallout, and thus is of considerable value. Further, since the Rongclap pcople were moved from their original habitat and then returned after a period of 3 vears, the relationship between body burden and changing levels of environmental contamination can be studied. Unfortunately, subse- quent weapon tests in the Pacific Proving Grounds durng the past 5 vears have to a degree interfered with the assessment of the relationship between environmental contamination and rate of equilibration of various of the fission products in the bods. insofar as the, have contributed small but detectable accretions to the contamination in this area. The procedures for sample collection. prepara- tion and radiochemical analvsis have been described (Rinehart et al, 1955: Weiss et al. 1956; and Shipman et al, 1955}. The most interesting new technical development in the field of fission product analvsis in human bemgs has been the application of the technique of whole-bod, gamma spectroscopy. In 1957 it was determined bv Miller that direct whole-body gamma counting of the Marshallese was feasible. A group of seven’ Marshallese was brought to Argonne National Laborators and counted in their whole-body counter. In 1955 and 1959. a ‘portable’ (20 ton) wholebodv counter, designed and built at Brookhaven National Laboratory, was taken out to the Marshall Islands for use in the annual medical survey. Several hun- dred Marshallese people were counted (Conard and Robertson, 1958; Cohn, 1959). The technique of whole-body spectrometry has been described by Miller (1959). RESULTS AND Discussion The radiation hazard to human beings resulting from habitation in an area subjected to radioactive contamination resides in the fate of the radioactive material deposited thereon. Radioactive material settling down on the carth’s surface is transported through the soil, air and water to plants, and thence to animals and finally to man. The levels of radioactivity in cach of these com.) -‘ ponents of the ecological chain from soil to man were measured and are tt ported below. External Dose The levels of radioactive contamination which fell on the Marshall Islands .- were reficcted by the doses that were received over approximately 48 hours 307