DRAET 16- via the inhalation pathway. This is the same approach used to evaluate the inhalation pathway at Enewetak Atoll (23). The mass loading concept may be more relevant for estimating the potential dose via inhalation than open air aerosol measurements because the resuspended material created by a person in his own immediate “environment may be significantly greater than is reflected in open air measurements. Therefore, it is assumed that the concentration of Pu observed in the surface soil at Bikini and Eneu Islands will remain the same in the respirable resuspended surface material. In addition, a mass loading of 100 ug per m3 and a breathing rate of 20 m? per day are used to develop the Pu inhalation rate in pCi per day. A mass loading of 100 yg/m? is at the high end of the observed range for norma] open air aerosol measurements. However, in view of the fact that local resuspension created in the immediate vicinity of an individual during his normal activities is probably greater than open air measurements, it appears reasonable, for lack of specific data, to use the higher number. The average Pu concentrations in the surface soils (0-5 cm) - for Bikini and Eneu Islands are 9.3 pCi/g and 1.4 pCi/g respectively. The pCi per day intake resulting from the above model is therefore, 0.019 and 0.0028 for Bikini and Eneu respectively. | The doses resulting from inhalation of 239,24°Pu are listed in Table 5 for the three critical organs: Lung, bone and liver. The doses predicted for Eneu are of course less than those predicted for Bikini Island. [a 500989 |