RESULTS AND DISCUSSION Daily Activity Ingestion Rates Daily activity ingestion rates were calculated for dosimetrically significant nuclides post return, An exponential decline was proposed for the inges- tion rate within a population subgroup and initial reference values are given in Figures 10 through 14 (June 1, 1957, was assigned as @ return date to Rongelap). Figure 10 demonstratee the differences in ingestion of 1376, for various popila- tion subgroups. This undulating pattern was exhibited by 1376, 905, and Orn, nuclides for which sufficientdata existed for analysis. Differences in ingestion rates of the stable element at: the same geo~ graphic location have been shown to occur among members of a population (ICRI tay 23). +etd Age dependent diet studies for ingestion of Cs for urbah' Japan have valuen varying from 1l yg av} for adults cto 8.6 ug a”for children, Sein a westein Fe ingestion in a western type diet has a mini~ mum at age 3 and maxima at ages 1 and 20 years. Co is ingested at a rate of 2() ug avi for Japanese adults and half this amount for children. The Marshallese population also exhibits dietary changes as a function of age. The authors of the Marshall Islands Diet and Living Pattern Study (Na80) observed coconut sap being used as a major food supplement for infants, and later in adult life as 4 major source of daily fluid intake. Since coconuts and coconut tree sap pro- vided the major source of 13705 on Bikini Atoll (Le80, Mi80), the shape of Fig: ure 10 was in agreement with the observed diet pattern. 22 ant observed in adult tea drinkers. BEE “Be abSy“ae a8 in the United Kingdom rose from 2 to 40 mg al, the higher value of Zn being weal + = 3,600 yg a7} for 13 year olds and fell to a mean of 1,900 isa"*tor adults. 2n ee a _ “ee Oe: ne at: ogee type diet rose from 600 pg a7!for infants to 690'ug d7 fox 5 year olds to