This information, combined with the lens-voluwze measurements end the data on efflux via exchange with seawater (tidal effects) being obtained in Noshkin's current lens-weter program will lead to a model for the kinetics of the soil/plent /lens-vater system. 3. Turnover of the Lens-Water System In. the lens-water studies of the marine group, importint results ere being obteined on dynamics, comcosition, and geographic Gistributicn of lens-water systems on many of the islends. An Independent measurement. o7 Lens-vater Pr such) as volume and dynamics can be made by using an effective water t tritiun. The samples that are being cbtained in the Nosnii ere used effectively to measure the volume, turnover, imter-iens comounic end input diluticn effects from rainfall end seawater. These resuitse con be verified by injecting the avprooriete amcunt of tritium intc several wells on the contaminated islands. The present program, if augmented by water-t studies, perhaps both by labelling of the internal lens-water and by surfi lebelling of tie soil above a lens, will vield ingenvendent, ecliateral measurements cr lens-water characteris s. This i possibility treat the turnover rate of the lens system c controlling factcr, other than radioact from the atoll environment. kh, ec = x Eveluation of Extermal Beta Dose In NVO-10 the beta dose was given only minor attention in the external dose measurements and calculeticns. In reviewing the data, Beck and MehLaugyhiin estimated that the -‘YSr/>*¥ beta free air dose at cne meter could be rour times the ice camma dose. The TLD's as used on Fnewetek hed scme sensitivity to bevas, whe aerial system none, and the porteble scintilicators practically none. Limited results from T measurements CUES she survey indicate considerable lower beta exposures than the estimere : cen be considered reliable due to the limited dete base. LS To complete the external dose estimates, the range of beta to gemma aose rates shculd be determined. The range of ratios must be erphasized as the ratio should vary widely due to ground cover, depth of burial, ote. A network for measuring beta doses will be established on two or three islands using a grid similar to that of the 1972 TLD survey. Belle and Daisy or Belle and Jenet are good candidates due to locetion, exposure rates end range of ground cover offered. Adeauete data can be obtained vith minimel instrumentation such as TLD's with special holders for bete response end thin window Gi survey instruments with panceke Gi probes and removalble shields. Data from these exper inents will permit e more comprehensive essessment of external dose to the skin of persons inhabiting the atolls.