inhalation at Bikini Island also of plutonium to a person's urine exceeds thap in New York. during the course of a year. The transfer coefficient across An inhalation pathway analysis based on a mass~loading concept the gut into the blood is assumed to similar to the one used for the be 3 x 107° for ingested plutonium. ©° Enewetak Atoll dose assessment” also At Bikini this would mean that indicates potentially higher intake 1.54 x 107° at Bikini by inhalation. to the blood. Using a pCi would be transferred Of this amount, mass loading of 100 ug/m> as in the approximately gylo st? or 1.2 Enewetak assessment; an average, 0- x 10°? pCi would be transferred to to 5~cm concentration of plutonium the urine. in Bikini soil of approximately that at Bikini the ingestion pathway 9 pCi/g;" and a breathing rate of contributes more than the inhalation 20 m>/day; we find the annual intake pathway to plutonium in the urine of via inhalation would be 6.6 pCi, man. compared with the estimate of 0.2 pCi based on aerosol measurements. . . 16 Inhalation experiments and dose We find from this analysis In New York, the contribution of ingestion to the total level of plutonium in urine (1.6 pCi x 3 modelg>?t°>4? indicate that approxi- x 1072 x 0.08 = 3.8 x 107° pci) is mately 0.1% of the activity inhaled negligible compared to the contribu- will be excreted in the urine. tion of the inhalation route. If. There- we assume that a person's annual fore the estimated total annual plu- intake via inhalation'is 0.2 pCi in tonium in urine would be 2 x 10° both Bikini and New York, inhalation for New York residents and 2 x 10. would contribute only 2 x 1074 pci 41.2107 =21.4 x 1077 pCi for Table 6. pCi 4 Comparison of estimated annual intakes of plutonium at Bikini with those at New York. , Pathway Est. annual intake, pCi/yr Bikini New York Inhalation 20.2 Drinking water” 8.7 Terrestrial foods 21.9 Marine foods a. 4 Cistern water only. 482 Ratio of intakes, Bikini/New York 0.2 ol 0.13 58 1.4 i5 0.024 2x 10 4 Any use of ground water would increase this estimate. -12?- 6032