~5future Bikini and Enewetak residents is being facilitated by including gutters and water storage tanks in plans for houses and community structures. Some of the larger islands have fresh ground water located only a few feet below the surface. Analysis of this water for its radio- nuclide content has been limited to date and the capacity of this resource to serve the needs of island residents is not well defined. More study of this water is being supported by ERDA,. PERSONNEL MONITORING Dose predictions for Bikini and Enewetak Atoll residents derived from . environmental data have been deliberately conservative, and establish probable upper limits on doses to be expected for individuals. Reliable assessments of actual doses must be determined through personnel monitoring. External radiation dosimeters do not appear to be a practical means of personnel monitoring for individual external dose measurements, although certain individuals within given populations may be relied upon to wear them. A "lifestyle model" which includes estimates of occupancy factors for various locations in a given atoll has been coupled with environmental monitoring data to estimate average external radiation doses to individuals. This model will be revised as needed so that it closely approximates the actual lifestyle of the people. The more important internal pathway can be monitored directly by conventional techniques of bioassay and whole-body counting of individuals. A portable shadow shield whole-body counter has been constructed and mounted in a shipboard trailer for use in the Marshall Islands. It is capable of quantitative detection of very small quantities of certain radionuclides in the body such as 137 Cs and 60 Co, the primary environmental gamma emitters at Bikini, Enewetak, and Rongelap Atolls. The system