.Fete ee “i feePT eaateed RRL eR ariaeee Pe seat ae pee ea ae, Seip * Vee a cy ard ADgyNS ; ae r . and sex subgroup distributions. This less pronounced variation may be due tu “a the fact that ©> 7 measurements took place over a 3 year interval while 905, and 1376, occurred over a 23 year interval and thus was contained in a more homogeneous population than were the longer lived nuclides. ; ede. 90 Figures 22 and 23a and 23b summarize the ! uy ~’Sr dose equivalent results for individuals at Ronge lap. In this analysis, only the ingestion pathway was considered important, Some radioactivity would enter the body via the resuspension and direct inhalation pathways. It is known that for a given soil concentration of ‘the Stable s * naturally occurring analogs to the radionuclides considered here, the ratio: : 5 | * i of food and fluid intake to blood relative to airborne intake to blood, are as follows: Co > 3000 Zn > 130 Fe > 550 Sr > 10,000 a Ce > 400 Thus, dietary intake of radioactive material is the principal pathway leadiig to internal deposition, This applies to most nuclides in the environment, howrver, there are notable exceptions including I, U, and Pu. External Exposure ag A value of .73 rade in tissue of interest per rontgen, measured in air at . A one meter above the surface, was used to convert exposure in air to absorhei dose in tissue. The source was assumed to be an exponential distribution of tivity with depth in soil, typical of aged fallout (Be70). 137, ae Because of the multidirectional nature of the source, variation of absorbed dose with depth of organ was minimal. Additionally, external doses were adjusted for living pat 43 mo